Welcome to 911UK
The only place for Porsche, 911uk is the definitive enthusiast and resource site for the Porsche 911.
Registration is fast, simple and absolutely free, so join up today for full access to the site and benefit from latest member offers.

Porsche Classifieds
Sell Your Porsche on 911uk
Create a Free Classified Advert
Search Ads
Classified Adverts FAQ
Trade Classified Information
Buyer & Seller Fraud Protection
Consumer Rights Act
Pre Purchase Inspection (PPI)
Porsche Car Sourcing
Porsche Cars Wanted
Official Porsche Centre Reviews
Model
Stock
Porsche 911
992 : 2019- 0
991 : 2011- 24
997 : 2004- 60
996 : 1997-2005 30
993 : 1993-1998 2
964 : 1989-1993 0
Carrera 3.2 : 1983-1989 2
Carrera SC : 1977-1983 3
930 Turbo : 1975-1989 1
Early 911 : 1964-1977 1
Porsche Other Models
Classic : 1950-1965 0
Boxster : 1997- 27
Cayman : 2005- 22
Cayenne : 2003- 7
Macan : 2014- 5
Panamera : 2009- 0
912-914-924-928-944-968 0
959 - CarreraGT - RaceCar 0
Car Parts For Sale & Wanted
Other Items For Sale & Wanted
Wheels Tyres For Sale & Wanted
Number Plates For Sale Wanted

Porsche Services
Porsche Body Shop Repair
Paint Protection & Wrapping
Porsche Classic Insurance
Porsche Classic Parts
Porsche Classic Restoration
Porsche Design Collection
Porsche Engine Gearbox Rebuild
Porsche Heritage & History
Porsche News
Porsche Picture Gallery
Win a New Porsche 911

Porsche Parts
Body Parts, Body Styling
Brakes, Clearance
Electrical, Exhausts
Engine Cooling, Engine Electrical
Engine Rebuild, Heating Cooling
Interior Incar, Lighting
Rubber Seals, Service Parts
Steering, Suspension
Transmission, Workshop Tools
Early 911, 911 - 930, 928 - 968
964 - 993, 996 - 997, Boxster
Cayman, Cayenne, Panamera

Porsche Model Range
911 [992] 2018-Current
Porsche 911 [992]
911 [991] 2011-2019
Porsche 911 [991]
911 [997] 2004-2012
Porsche 911 [997]
911 [GT] GT1-GT2-GT3
Porsche 911 [GT]
911 [996] 1997-2005
Porsche 911 [996]
911 [993] 1993-1998
Porsche 911 [993]
911 [RS] RS-RSR
Porsche 911 [RS]
911 [964] 1989-1993
Porsche 911 [964]
911 3.2 1983-1989
Porsche 911 3.2 Carrera
911 SC 1977-1983
Porsche 911 SC
911 [Early] 1964-1977
Porsche 911 [Early]
Boxster & Cayman
Porsche Boxster & Cayman
Cayenne & Panamera
Porsche Cayenne & Panamera

911uk Site Partners

Post new topic   Reply to topic
Author Message
Marky911
Sepang


Joined: 04 Jun 2009
Posts: 2829



PostPosted: Sat Jul 27, 2019 8:03 pm    Post subject: Reply with quote

^^^ I agree totally.

There are some cracking threads gaining momentum at the moment. We have this one, Rich ELA has just bought himself a Spyder and then there’s the M96 lads like Crash, MC and Dammit with their boundary pushing. Plus many others.
It all makes for some great reading.

I’m enjoying the suspension updates Henry. A stark reminder that even with the best intentions at installation time, the most minor of issues or iffy decisions can lead to all sorts of problems further down the line.
As you say Matty at FS had no option but to fit the remote canisters where he did really, but it caused a headache later.

I can’t believe the 90mm holes cut in there. Surprised
Good fix though. As you say it looks almost factory.
It’s unbelievable and slightly disheartening what the so called experts do sometimes. We hand our cars over for top notch knowledge and attention.
Very disappointing.

Looking forward to the next instalment. Thumb
 
  
View user's profile Send private message
   
The return of Marty Wild
Kyalami


Joined: 04 Nov 2016
Posts: 1969



PostPosted: Sat Jul 27, 2019 8:09 pm    Post subject: Reply with quote

You’re one of the perps, you doughnut Grin

It is awesome to see what you guys get up to, especially those lucky enough to have a GT3 in the stable.
_________________
Life's too short for cr4ppy cars, keep it German!

Boxster S 986.1
Cayman S 987.1 (gone but not forgotten)
 
  
View user's profile Send private message
   
Marky911
Sepang


Joined: 04 Jun 2009
Posts: 2829



PostPosted: Sat Jul 27, 2019 10:19 pm    Post subject: Reply with quote

Haha, cheers. I’m a lightweight though.

And yes it’s nice to see that 996 GT3s are still getting some love and appreciation.
 
  
View user's profile Send private message
   
The return of Marty Wild
Kyalami


Joined: 04 Nov 2016
Posts: 1969



PostPosted: Sun Jul 28, 2019 5:19 am    Post subject: Reply with quote

Nah, your thread is anything but lightweight.

996 GT3s will always receive the love they deserve, they’re the originators. My mate has a gen2 tucked away that he tries not to use as its on its way to 50 on the clock. Now things have softened a touch, maybe he needs to get it out more.
_________________
Life's too short for cr4ppy cars, keep it German!

Boxster S 986.1
Cayman S 987.1 (gone but not forgotten)
 
  
View user's profile Send private message
   
ELA
Barcelona


Joined: 30 Aug 2011
Posts: 1347
Location: Nurburgring Doorstep


PostPosted: Sun Jul 28, 2019 6:01 am    Post subject: Reply with quote

Cracking stuff H, it's all the intricate fiddly tasks which go seemingly unnoticed, which change a good car into a great car Thumb
Shocked to see professional outfits committing some of the heinous acts you have depicted here, but perhaps you have misunderstood the genius of the butchering; to the uninitiated these mortar shell lesions are as you cleverly describe (great surname alteration Grin ), however perhaps they were seeking out a few critical grams of weight loss, as you know how badly the 911 is rear biased Grin I may even steal this idea for a few of my projects.
Keep up the great work Thumb
_________________
CLR996 1086kg bespoke design
 
  
View user's profile Send private message Visit poster's website
   
Johnd52
Montreal


Joined: 06 Oct 2014
Posts: 624
Location: North Yorkshire

2011 Porsche Cayman 987

PostPosted: Sun Jul 28, 2019 6:59 am    Post subject: Reply with quote

A great thread(s!) about a great car. Thank you for posting about your ongoing development work and dedication to getting it ‘right’

Having read it through a couple of times I am still not understanding why the damper reservoirs cannot be inside the car. I would have thought that attaching them to the hub or arms would be a no-no, increasing unsprung weight and putting them in a fairly hostile environment.

I am really intrigued to see where this takes you. Next instalment soon please.
_________________
2015 Cayman GTS. No more PDK but still red.
 
  
View user's profile Send private message
   
Slippydiff
Nürburgring


Joined: 22 Nov 2007
Posts: 417



PostPosted: Sun Jul 28, 2019 9:42 am    Post subject: Reply with quote

Johnd52 wrote:
A great thread(s!) about a great car. Thank you for posting about your ongoing development work and dedication to getting it ‘right’

Having read it through a couple of times I am still not understanding why the damper reservoirs cannot be inside the car. I would have thought that attaching them to the hub or arms would be a no-no, increasing unsprung weight and putting them in a fairly hostile environment.

I am really intrigued to see where this takes you. Next instalment soon please.


Thanks for all the kind comments guys, they’re much appreciated. It’s a shame we can’t get more threads like ours on here. In the past I’ve really enjoyed reading Marky’s and Richards threads, and whilst they’re enjoyable to read, they also provide really useful information on what bits look like and how to remove/strip/refit them.

I’m looking forward to Richie’s posts on the Spyder , and also Marky’s upcoming Euro tour (I’m deeply envious BTW Mark) as I’ve not been over to Europe with a car in at least 5 years now.

Anyway guys, keep up the good work, as the more of “our” type of the threads on here, the less residuals/best spec for investment, should I tick the contrast/deviated stitching box ? threads there’ll be ...

John, there’ll be a better explanation as to why the Ohlins canisters couldn’t go IN the car itself when I cover the front suspension Thumb
 
  
View user's profile Send private message
   
Slippydiff
Nürburgring


Joined: 22 Nov 2007
Posts: 417



PostPosted: Sun Jul 28, 2019 3:31 pm    Post subject: Reply with quote

Front Suspension

In light of my findings with the rear suspension, I thought it prudent to check the front damper/canister install too.
As it turned out, it was a wise decision, as a careful inspection revealed this :



The image shows the banjo for the remote damper hose where it meets the damper body itself, just beneath the top mount, slightly weeping/leaking.

So to answer John's question as to why the Ohlins remote canisters aren't/can't be mounted inside the car itself :

The internals on any high end damper are incredibly close tolerance/precision machined components, be that the valves, the damper rods or the pistons.

Good quality damping relies on moving large quantities of damping oil at high velocity through jets (holes) via valves or shims, this volume of oil needs to be moved incredibly quickly, but in a highly controlled manner.

The shims (some of which are wafer thin) are discs of metal which deflect as the hydraulic pressure is applied to them, and as they deflect, they allow hydraulic oil (damper oil) to pass through a hole or a series of holes in a highly controlled manner. By adjusting the thickness and number of the shims (the shim stack) the damper characteristics or "valving" is tuned/adjusted.

The oil within the damper needs to be maintained at a certain pressure, firstly to stop cavitation of the oil, but it can also be used to provide a secondary springing medium to further fine tune the damper's characteristics (and the car's ride). The best gas for this is nitrogen, it's cheap, inert and stable when temperature of the damper increases.

By fitting long hoses between the damper body and the remote canister (such as those that would enable you to place the canister within the cabin or the luggage area in a 911) you introduce an element of hysteresis (effectively though the damper oil is not compressible, the flexibility in the walls of a long length of hydraulic pipe, will flex and create hysteresis (lag))
It's this “delay” in the pressure being transferred to the shim stacks and valves in the damper, that Ohlins aim to minimise.

Doing so means the hydraulic hoses between the damper body and the remote canister that Ohlins specify, are high quality, but pretty inflexible and they tend to keep the runs to the absolute minimum length. Great for maintaining optimal damping accuracy, but a royal PITA for locating the canisters on a car from a purely practical perspective.

To minimise ANY chance of leaks, Ohlins don't fit dry break connectors to these lines, neither will they utilise banjos that enable the hoses to swivel in use, where they connect to the canister or the damper body, and this in addition to the limited length of the hoses, often makes finding a location for the canisters difficult, and the hose runs sub-optimal if not downright awkward.

With space limited behind the headlamps due to the compromised HID install, finding a suitable location for the front canisters was proving tricky. With the added complication that the hoses need to be kept away from the wheels/tyres which are not only moving up down, but being steered left and right too …

On the face of it, Matt's decision to mount the canisters on top of the front uprights/hub carriers was questionable, but in his defence, his options were pretty limited.

I have to say I harboured genuine concerns from the minute I saw their location on the uprights, primarily due to the heat that would be generated by the front brakes and their close proximity to the canisters, but also because I intended fitting large diameter brake discs.

Having found the weep from the hose connection banjo at the damper body, I guessed there was an issue with the hose run. A check to see if the banjo bolt was loose and causing the weep, indicated it was just loose enough to allow the banjo to rotate minutely when the front suspension was at full droop. In other words, the hose was just too short and being over-extended at full stretch (maximum suspension droop)

Whilst Ohlins won't fit banjos to the end of the hoses that articulate freely whilst in use, they've engineered the whole “collar” (the brass thing that can be seen at the top of the damper below the top mount) that the banjo bolts onto, to enable it to rotate (it's clearly cleverly sealed) however even this slight bit of rotation/articulation was insufficient to stop the banjo/ banjo bolt and it's dowty seals/washers from leaking.

Unfortunately the remote canisters/dampers are pressurized with between 10-15 bar (that's 150-220 psi in old money) of nitrogen, so any leaks are a fairly major problem, all the moreso as should all the gas pressure leak out, the lack of pressure behind the valves in the remote canisters can allow them to hit their seats and cause expensive damage.

All of which meant the dampers needed to be removed to have their pressures checked and adjusted. A call to BG Motorsport at Silverstone established the eye watering cost of replenishing and re-gassing if required ...

Removing the front dampers is pretty straightforward (or should be … !!)
Actually it is a straightforward job, but my ineptitude meant I caused a further (brake system) complication in the process. Doh !!

The front dampers were subsequently removed and checked. One was found to be at 12 bar, the other (weeping) one was found to have dropped to 11 bar, and on the basis less than nought point nought percent of chuff all damper oil had actually leaked out of it, we just recharged the offending damper back up to 12 bar.

Doing so requires this piece of kit :



https://performanceshock.com/index.php?main_page=product_info&products_id=679&zenid=b3d8ede2bd68f6eee97f23fcec7b86d7

and a cylinder of nitrogen.

The recharging process involves removing the screw (arrowed in red here) on the remote canister :



This exposes a self sealing rubber diaphragm. A hypodermic needle is pressed through the diaphragm. At the base of the needle is a boss with a thread that fits into the thread in the canister housing that the sealing plug/screw has previously been removed from.

Onto the boss is fits an adapter (it's the gold bit you can see in the image of the kit) that houses a pressure gauge, and a valve which enables you to bleed off or add pressure.

All pretty straightforward, though it becomes considerably more complicated if you need to add additional damper oil …

With the dampers checked and re-gassed, I put them back on the car, albeit this time with the canisters re-located somewhere they wouldn't be exposed to excessive heat and their pipe runs would not be under tension at full suspension droop.

With the front arch liners completely removed to fettle them and the various brake ducts, it became obvious fairly quickly that finding an alternative location for the canisters would be easy. And after a bit of trial and error, an alternative location was found that is stealthy (you can't see the canisters at all from under the car now) far more protective of the canisters themselves, their hoses, AND ensured the hose runs were completely unstressed and the radii of the their runs smooth and gentle :







With the use of some rubber mounting blocks and some sturdy cable ties, the canisters now reside behind the arch liners, away from any flying debris and the worst of any rain etc etc.

I toyed with the idea of using a 90mm tank cutter to cut a hole in the front arch liners to make a circular access "window" to enable adjustment of the rebound and compression adjusters on the canister without having to remove, or partially remove the archliners, which I'd close using the 90mm rubber grommets I used for the the rear inner wheel arch repairs.
But I figured that having set the adjusters to what BG Motorsport and I had previously determined were the optimal settings (more of which later) there wasn't a lot of point really.

Last edited by Slippydiff on Wed Jul 31, 2019 1:27 pm; edited 2 times in total
 
  
View user's profile Send private message
   
JamieG
Newbie


Joined: 24 Feb 2008
Posts: 19



PostPosted: Sun Jul 28, 2019 7:16 pm    Post subject: Reply with quote

Evening Henry, another cracking thread about your fabulous car. Glad to hear you have been out enjoying the brute. Please keep these threads coming! (PS - think I missed my chance with your old Manthey-car Sad )
 
  
View user's profile Send private message
   
Johnd52
Montreal


Joined: 06 Oct 2014
Posts: 624
Location: North Yorkshire

2011 Porsche Cayman 987

PostPosted: Sun Jul 28, 2019 9:29 pm    Post subject: Reply with quote

Thanks for the detailed write up on the suspension and the damper units. Being regularly on here provides a lot of education, but occasionally you get a degree course. Amazing work.
_________________
2015 Cayman GTS. No more PDK but still red.
 
  
View user's profile Send private message
   
Slippydiff
Nürburgring


Joined: 22 Nov 2007
Posts: 417



PostPosted: Sun Jul 28, 2019 11:04 pm    Post subject: Reply with quote

JamieG wrote:
Evening Henry, another cracking thread about your fabulous car. Glad to hear you have been out enjoying the brute. Please keep these threads coming! (PS - think I missed my chance with your old Manthey-car Sad )


Email sent Jamie Smile
 
  
View user's profile Send private message
   
Y2K
Montreal


Joined: 08 Mar 2016
Posts: 552
Location: Hampshire


PostPosted: Mon Jul 29, 2019 4:17 am    Post subject: Reply with quote

Quality stuff, keep ‘em coming.
_________________
2005 996 GT3 mk2
1999 Integra DC2
 
  
View user's profile Send private message
   
JamieG
Newbie


Joined: 24 Feb 2008
Posts: 19



PostPosted: Mon Jul 29, 2019 7:35 am    Post subject: Reply with quote

Slippydiff wrote:
JamieG wrote:
Evening Henry, another cracking thread about your fabulous car. Glad to hear you have been out enjoying the brute. Please keep these threads coming! (PS - think I missed my chance with your old Manthey-car Sad )


Email sent Jamie Smile


Thanks Henry - reply sent
 
  
View user's profile Send private message
   
Marky911
Sepang


Joined: 04 Jun 2009
Posts: 2829



PostPosted: Mon Jul 29, 2019 11:20 pm    Post subject: Reply with quote

Great work again and especially on the front canister location. I was racking my brains as I read the post, questioning where I’d put them?
Great solution, especially with the protection offered by the arch liners. Thumb
 
  
View user's profile Send private message
   
Slippydiff
Nürburgring


Joined: 22 Nov 2007
Posts: 417



PostPosted: Tue Jul 30, 2019 12:07 pm    Post subject: Reply with quote

Rear Brakes

And so on to the brakes …

There were several very specific briefs for the brakes. But first a quick overview of the existing brake set up :

The car was fitted with Mk2 six pots on the front with Alcon floating discs, and Alcon 350mm rear discs utilising the standard rear calipers spaced out with bespoke 10mm spacers. Both sets of Alcon discs were within their wear limits (the rears only just) but had had a hard life and the rears were badly Mick Jagger'ed Very Happy





I asked the previous short term owner to remove the Endless front pads, as whilst their stopping abilities were beyond compare, they squealed like a London bus, something Mark is finding intolerable with the RS29's in his car currently. I concur that I find the noise equally unacceptable.

In place of the Endless pads went a set of completely shot, 70% worn Pagid RS29's.

Some of you will know that high performance brake pads used repeatedly on track and subjected to frequent high temperature heat cycling, causes the various elements of the lining to be burnt off and/or them changing in their composition accordingly.

The end result of this process is a large drop in the lining's coefficient of friction, this in turn leads to a wooden feeling brake pedal that lacks any real bite and this in turn increases disc temperatures and wear.
RS 29's have gained a reputation for losing their efficiency once 60-70% worn

The rear pads were standard OE Textar items that were 75% worn and again, well past their best …

And so the the brief.
This is a fast road car, so the likes of the track biased discs from companies such as Alcon, Performance Friction or Brembo weren't even considered.
I wanted drilled rather than grooved or hooked disc faces.

The pads needed to be OE spec, easy to bed in, to work from cold, but work consistently at higher temperatures also. They'd also need to be OE from a NVH perspective, so no squealing, no vibration, no excessive noise under heavy braking from high speeds.

On the basis the engine now produces 465hp and the car weighs in at 1450kgs ?? I figured that Gen 1 997 Turbo (480+ hp, waaaay more torque and a kerb weight probably closer to 1750kg) brake components should be more than equal to the task.

The easy option would have been to fit a set of OE spec 350mm steel “boat anchors” both front and rear, and that's what I went with for the rear discs. For the fronts I went for a somewhat more bespoke set up.

Rear Brakes.

A set of Sebro (they're an OE supplier) 997 Turbo 350mm rear discs were purchased (£89 plus vat each) along with a set of Textar 996 GT3/997 C2S front pads (they're the same pad profile as the 996 GT3/Turbo rear pads)

With the car up on stands for the now completed suspension fettling, I figured the rear disc and pad replacement would be a maximum of half an hour a side … Fat chance Floor

With the pads removed and the handbrake shoe adjusters backed off, the old Alcon discs came off to reveal the handbrake shoes on the O/S almost worn down to their backplates ... Question

Matt had removed the rear calipers and discs to Timesert the rear caliper mounting bolts. This was necessary as some bright spark had used the original rear caliper mounting bolts, despite having fitted 10mm spacers to the caliper mounts, this left precious little thread for the bolts to screw into, and thus the remaining thread was overstressed and s t r e t c h e d.

At the same time as the threads were Timeserted, the handbrake shoe retaining/hold down springs were replaced (the new retaining springs can be seen in the image) as they'd failed and were allowing the shoes to cant over (and as a result bind) instead of running parallel to the handbrake drum surface :



And these are the same shoes less than 200 miles later (this the good end of the shoe, the lining on the other end was a wafer thin sliver) :



WTF

A quick call to Porsche confirmed I wouldn't be buying OE replacement set of shoes of them !! So thoughts turned to having the shoes re-lined, but before doing so, I thought it would be worthwhile giving the company I'd bought the rear discs along with the front and rear pads off, a ring for a price. Just as well, they supplied a set of four Mintex shoes for the princely sum of £25 plus VAT. Dance Tap

With the shoes purchased I attempted to fit them. Let me say here and now, the handbrake linkage assemblies are fiendishly fiddly items (they're used on the 968, 964, 993, 996, 997, 986 etc) and despite having taken several images prior to stripping them down, rebuilding them wasn't a straightforward undertaking.

Having pulled the N/S apart and cleaned, inspected, lubricated and reassembled it, I thought the O/S would be a breeze … Rolling Eyes



Having started to strip it down, I found that the pivot pin (blue arrow) was partially seized. As was the handbrake cable attachment pin (yellow arrow)

This pin floats freely (and is only about 8 mm long) and is retained/held captive by the sides of the stirrup (white arrow) but worse still the lever (black arrow) it runs in was fouling and binding inside the stirrup that retains the pin.

With it freed off and stripped down I set about tweaking the pressed steel stirrup to allow some additional clearance for the lever and the pivot pin that runs within it.

The stirrup is 2-3mm thick piece of mild steel that had been stamped into the required shape then folded and spot welded (red arrow) to hold the ends together.

Simple I thought, install a couple of small pry bars between the two sides, and then I'll spread them sufficiently to clear the lever that runs between them.

A quick “pry” revealed the lever was tougher than it looked … So on the basis brute force and ignorance can shift anything, I pryed (is that even a word ?) somewhat harder. At which point the tiny (2mm) spot weld failed.
This was the culmination of long, drawn out, irritating (nee downright annoying) and frustrating day Gun Fire

Tools became airborne, as did the broken stirrup. Meanwhile the neighbours most likely thought the bloke next door had a bad case of Tourette's …. Grin

I shut the garage door behind me and kicked the cat before downing a large glass of Amaretto.

The following morning I took the broken stirrup to my local fabricator/welding guy. Five minutes of filing/grinding prep, followed by 2 minutes TiG welding and a further two minutes on the grinder and the strirrup was now worthy of being considered a MotorSport heavy duty uprated part.

Back home for 9am, the O/S shoes and linkage were reassembled and back on the car within twenty minutes.

(Tip : Snap-On make a superb tool that enables you to easily press these springs in and then rotate them 90 degrees to secure them, but a pair of thin-nosed Vise-Grips do the same job perfectly, although the pointy bits really dig into your palm when you use them in this manner) :



The new brake disc was degreased and offered up, but wouldn't fit over the new and freshly assembled shoes and linkage … Splat

Some head scratching and disassembly of the shoes and the linkage, revealed the linkage was “too long” thus forcing the shoes apart sufficiently to stop the disc going over them. This despite the shoe adjusters being fully backed off.

Further investigation/analysis of the linkage showed it's fulcrum point was making its effective length too long, with no obvious way of shifting the fulcrum to decrease its effective length.

If all else fails, go on Youtube, and it was here the answer was to be found in the shape of a DIY video on adjustment of the handbrake …

Prior to adjusting the handbrake shoes within the drums themselves, the handbrake adjustment itself needs to be backed right off.
With the majority of the screws retaining the centre console removed … I happened across the one that secures the glovebox/cubby hole floor panel, and with it and the floor removed, the handbrake adjuster mechanism was revealed in all it's misadjusted glory :



Rolling Eyes

With the locknut undone and the adjuster nut backed off, the rear disc flew over the newly fitted shoes Thumb



The handbrake shoes were adjusted at the hubs and the handbrake lever subsequently adjusted in the cabin.

Sorting that lot out took considerably longer than the hour it should have done to fit new rear discs and pads ... and had the handbrake shoe linkages been checked when the retaining springs were replaced, along with the handbrake shoes and lever itself being adjusted correctly, would have been completely unnecessary...

Last edited by Slippydiff on Wed Jul 31, 2019 1:28 pm; edited 2 times in total
 
  
View user's profile Send private message
   
infrasilver
Fast & Furious
Fast & Furious


Joined: 04 Oct 2010
Posts: 8560
Location: East Midlands

2001 Porsche 996 Targa

PostPosted: Tue Jul 30, 2019 12:42 pm    Post subject: Reply with quote

Considering it's old tech, the Porsche handbrake system is a pain to get set up correctly. I've been through this with both my 996 and 944, both the same set up and both equally annoying.

My 944 had been plagued with handbrake MOT fails and advisories over the last decade with previous owners and their mechanics, it took me some thinking and time to actually get it sorted for the first time in a long time, both cars work a treat now but as you found out there is a procedure to follow to get it working well and not binding.

I have used Mintex shoes on mine and there is also significantly more pad material, in length than the shoes that were removed.
_________________
http://euroroadtripper.blogspot.co.uk/

 
  
View user's profile Send private message Visit poster's website
   
Slippydiff
Nürburgring


Joined: 22 Nov 2007
Posts: 417



PostPosted: Tue Jul 30, 2019 1:09 pm    Post subject: Reply with quote

infrasilver wrote:
Considering it's old tech, the Porsche handbrake system is a pain to get set up correctly. I've been through this with both my 996 and 944, both the same set up and both equally annoying.

My 944 had been plagued with handbrake MOT fails and advisories over the last decade with previous owners and their mechanics, it took me some thinking and time to actually get it sorted for the first time in a long time, both cars work a treat now but as you found out there is a procedure to follow to get it working well and not binding.

I have used Mintex shoes on mine and there is also significantly more pad material, in length than the shoes that were removed.


Agreed. It's positively "Dickensian", but not helped by what are clearly lazy technicians not being bothered to delve into its intricacies or seemingly adjust it properly/at all.
Once stripped, freed off, lubricated and reassembled correctly AND adjusted properly, it's "functional" if not particularly pleasant to use.

I noted the increased lining length, it almost had me scuttling to the phone to question the supplier as to whether he'd supplied the correct part. But a back to back comparison showed the backplates were all but identical.
 
  
View user's profile Send private message
   
Pip1968
Suzuka


Joined: 26 Oct 2009
Posts: 1205
Location: Blighty


PostPosted: Tue Jul 30, 2019 7:20 pm    Post subject: Reply with quote

Good effort Slippydiff, I think we all have those simple tasks that turn into epics. In the early days it was usually caused by not having the correct tools. These days one is always looking for a new fabulous tool to add to the collection (I bought one of these [below] rotator ratchets recently on recommendation - ideal for tight spots where you cannot lever the ratchet)

To be honest though I am surprised the shoes are so badly worn. I rarely if ever use the handbrake going on the Norway premise where in Arctic you never put the handbrake on as it is likely to freeze to the discs. I always leave in gear and only use it after a track session to keep off the main brakes or on a hill start.

Trouble is with these post is you think "Hmmm .....perhaps I should put new pads on just in case"

Looking forward to the next episode.

Pip
 



Facom rotator drive.jpg
 Description:
 Filesize:  3.96 KB
 Viewed:  2277 Time(s)

Facom rotator drive.jpg


  
View user's profile Send private message
   
Slippydiff
Nürburgring


Joined: 22 Nov 2007
Posts: 417



PostPosted: Tue Jul 30, 2019 8:29 pm    Post subject: Reply with quote

Pip1968 wrote:
Good effort Slippydiff, I think we all have those simple tasks that turn into epics. In the early days it was usually caused by not having the correct tools. These days one is always looking for a new fabulous tool to add to the collection (I bought one of these [below] rotator ratchets recently on recommendation - ideal for tight spots where you cannot lever the ratchet)

To be honest though I am surprised the shoes are so badly worn. I rarely if ever use the handbrake going on the Norway premise where in Arctic you never put the handbrake on as it is likely to freeze to the discs. I always leave in gear and only use it after a track session to keep off the main brakes or on a hill start.

Trouble is with these post is you think "Hmmm .....perhaps I should put new pads on just in case"

Looking forward to the next episode.

Pip


Hi Peter, I’m like you when it comes to handbrakes, I rarely if ever use the things.
The N/S handbrake shoes would have gone again inside the new discs, though the O/S definitely wouldn’t.

Put simply, the accelerated, excess wear (less than 200 miles since the shoe retaining springs were replaced and the shoes adjusted) was due to the two pivots (the cable attachment pivot pin AND the pivot pin of the activation lever) being seized or partially seized, along with the activation lever getting jammed in the stirrup due to a lack of clearance.

In addition to the above, which would have made adjusting the shoe to drum clearance accurately all but impossible, the adjuster on the end of the handbrake cable/s at the handbrake lever, hadn’t been backed off at all, and by not not doing so, trying to adjust the shoe at the hub was a pointless and expensive exercise in futility.
 
  
View user's profile Send private message
   
Slippydiff
Nürburgring


Joined: 22 Nov 2007
Posts: 417



PostPosted: Wed Jul 31, 2019 11:19 am    Post subject: Reply with quote

Front brakes.

Fortunately the car was fitted with the Mk2 6 pot front calipers, and whilst they were in reasonable condition aesthetically, I thought it best they went away for a purely mechanical refurb.

I mentioned in a previous post, that whilst removing the front dampers, I'd made a faux pas, that being that whilst I was manhandling the the N/S strut out of the hub carrier/upright, the caliper which I'd carefully balanced out of the way, fell off it's temporary perch, in doing so the full weight of the caliper was born by the braided hydraulic brake line. It may have been undamaged and unstressed, but knowing it had happened meant I now had to replace it, and whilst doing the N/S, I may as well also replace the O/S.

With both calipers removed from the car, I inspected the dust seals, all twelve had disintegrated and were in need of replacement and several of the ceramic pucks had separated from the ends of their pistons too.

I rang a couple of Brembo agents to get the prices for the primary piston seals and the dust seals (and the cost of replacement pistons with their ceramic pucks) The figures were truly eye watering.

So I decided to take the calipers over to Bigg Red at Worcester to be mechanically refurbished.

My first question to them was : Are the replacement seals they supply genuine Brembo items ?

They informed they were not, they were manufactured by a well regarded Spanish company who supplied seals to a host of automotive suppliers and brake component manufacturers.

Bearing in mind the good reviews Bigg Red seem to get and the volume of calipers being overhauled in their workshops, they must be doing something right. So despite concerns over the non OE seals being used, I elected to get them to do the refurbishment.

This would entail cleaning and stripping the calipers, fitting new primary seals, dust seals, bleed nipples and finally, pressure testing them ...

They had the calipers for three days, and their costs were very reasonable. Whilst delivering the calipers to them, I noted they also manufactured Hel braided brake lines. Accordingly I provided them with the braided line off the car and asked them to replicate a pair.

With the calipers now overhauled, I was left waiting for the AP front discs to be supplied and the custom bells to mount them to be manufactured.

I'd planned to fit 380mm X 34mm discs, but I suspect that clearance (even with the BBS E88's) would have been on the tight side. So I settled for 365mm X 34mm Audi B7 RS4 front discs. These are a standard AP Racing part (albeit they have 6-8 week lead time) Rolling Eyes

They're reasonably priced, but have the benefit of being supplied with the required mounting bobbins, securing nuts, bolts and washers and anti rattle springs included in the price. Two bobbin sets would be required and they'd normally cost £50 plus vat for each bobbin kit. Thus making the discs considerably cheaper.

https://www.part-box.com/ap-racing-front-brake-disc-right-hand-side-audi-rs4-b7-rs6-c5-365x34mm-cp8080z14sd

These aren't much (if any) lighter than 362mm Alcons, but both are lighter than the OE one piece 350mm “boat anchors”.

The bells took some weeks to manufacture, but were worth the wait. They're as light as feather and nicely finished with a durable hard anodised process.





The slightly larger discs also required some slightly thicker 8mm caliper spacers, these were supplied with the bells.
To ensure the front pads were easily bedded, quiet and worked from cold, but also up to the rigours that would be imposed upon them, I went with a set of TRW 997 Turbo items.

I did a dry build, but needn't have bothered, the whole lot bolted up easily and fitted absolutely perfectly thumbsup

Fitting the new Hel braided brake lines wasn't so straightforward …
When I came to fit them to the car, the diameter of the bosses on the chassis end of the pipes were too large to fit the brackets that secure the connection between the hard line and the flexi pipe on the inner flitch.
Of course I could just have opened out the hole in the brackets, but that was never going to happen. So I returned the pipes and Bigg Red credited me in full.

I asked if they could supply them with bosses that were the correct diameter. They said they'd have to speak to the manufacturer in Germany, but they rang me a day later to say Hel couldn't supply the correct fittings to enable them to manufacture the pipe.
I suspect they could, but they would probably have to have bought a box of 100, and they didn't want a box of 96 of them sitting on the shelf for the next ten years …

Next stop James Lister Motorsport in West Bromwich. They manufactured a set of braided hoses that fitted perfectly, though their hose ends didn't have a flange formed adjacent to the hexagonal part of the boss (to stop the pipe pulling through the bracket on the inner flitch) …

This was easily addressed by getting a mate to machine me a couple of chunky washers that fitted tightly over the circular boss, but not the hexagonal section.
The braided hoses cost the princely sum of £18 plus vat for the two … The washers were FOC.

With the discs and calipers fitted and plumbed, I tried to bleed the brakes (and let me state for the record, I HATE brake fluid, and I HATE working with brake fluid even more !!) I always have, and always will. Horrible slimy stuff that gets everywhere, and is difficult to shift when spilt in large quantities …

I don't mind bleeding brakes on my own, though the bleed pipes I use are effective (they're just plastic pipes with one way valves on their ends) they're old and the rubber ends tend to slip off the bleed nipples on the calipers, and when they do so, they spray brake fluid everywhere. Hence my hate of the infernal stuff.

I've learnt to secure the rubber ends of the hoses to the bleed nipples with small cable ties, but it makes the job I hate doing already, more time consuming and more of a PITA !!

So with my magic bleed kit fitted to both nipples on both front calipers, and the M/C reservoir full of Motul RBF 660, I pumped the pedal to get the fluid through (not forgetting the front calipers had been off the car two months and the fluid had long since dripped out of the pipework)

Try as I might, I couldn't get a pedal of any sort. A check of the N/S/F caliper revealed a large pool of brake fluid on the floor beneath it …
I double checked the hose connections, then the bleed nipples (I only back them off ½ to ¾ of a turn to reduce the chances of air getting back into them), all looked fine, so I cleaned the caliper with brake cleaning fluid and tried again.
Same result …

This required further, close examination, and with the pads removed, it became clear the leak was coming from one of the pistons/seals, witnessed by a small stream of brake fluid running in a tiny, neat, barely visible stream from the piston's dust seal.

Bigg Red had told me they pressure test all their rebuilt calipers, so to find a caliper leaking in this manner was “unexpected” to put it mildly, not too mention less than confidence inspiring …

A call to them saw them agree to collect the leaking caliper from my house that evening. And sure enough the boss (Phil ?) appeared to collect it.

I asked if I could have the caliper back the following day. To which he replied yes, but I'd have to collect it as he was going to a funeral. He suggested I ring them mid- morning to see what the problem was and when the caliper would be ready for collection.

Sure enough I rang Bigg Red at 10am the following morning to see what progress had been made. Seemingly no one knew anything about this leaking caliper …. Hmmm Question

I explained the situation to them, and was promised they'd ring me back within the hour to give me an update. Fair play to them, they rang back half an hour later and said they were pressure testing the caliper now, and that it would be ready for collection by lunctime.

I duly collected it and was informed that they'd found a faulty seal which they'd now replaced and pressure tested. I fitted the caliper to the car and bled the system without any further problems.

I have mixed emotions about Bigg Red, primarily because I can't see how a seal fails between a caliper being rebuilt and being pressure tested and the caliper being fitted to the car some 3-4 weeks later ? The cynic in me says it wasn't pressure tested after being rebuilt and I dislike being lied to, least of all about such a safety critical component.

The whole episode left me lacking confidence in their ability to overhaul what is a critical part of the car's braking system.
No matter, here's the end result of my labours :





I'm very pleased with the outcome of the brake system overhaul/replacement and my impressions of these (and all the work I've carried out to the car) will follow once I've completed my reports on tweaking the cooling system and sorting the car's bodywork Smile

Last edited by Slippydiff on Wed Jul 31, 2019 1:35 pm; edited 2 times in total
 
  
View user's profile Send private message
   
Display posts from previous:   
Post new topic   Reply to topic   All times are GMT - 12 Hours
Goto page Previous  1, 2, 3, 4  Next
Page 2 of 4

 
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum
You cannot post calendar events in this forum