Gearbox pressurised?

Shalmaneser · 12 Oct 2021

Slightly odd one. Reverse light had stopped working, bulbs all good so bought a new reverse light switch for the gearbox. Reverse lights now working again, but when I undid the old switch from the gearbox casing there was a definite hiss of air escaping from the box.

Is it possible the breather has failed somehow and would this cause the internal volume to pressurise? I can't see this being normal and obviously keen to not blow out a seal.

Alex · 12 Oct 2021

Didn't know they had a breather :dont know:

I would've thought they are reasonable air tight as the oil stinks if its quite old and doesn't 'arf wiff when drained.

infrasilver · 12 Oct 2021

There is a breather on the top of the box, just a basic thing that lifts up under any kind of pressure, mine is slightly corroded but still moves easily so maybe something to look at?

Shalmaneser · 12 Oct 2021

There is a breather up there I'll see if I can give it a wobble. Might have bashed it fitting the box I suppose.

infrasilver · 13 Oct 2021

Just looked for the part number for the "bleeder" as it is called 99630107100, £4.20 ish, I have never removed mine so I'm not sure how it comes out

Shalmaneser · 14 Oct 2021

infrasilver said:
Just looked for the part number for the "bleeder" as it is called 99630107100, £4.20 ish, I have never removed mine so I'm not sure how it comes out

Thanks, it does as you say look a total arse to get to.... Will report back.

P0tential · 15 Oct 2021

The breather is pressed in and located way on top of the gearbox. Could be impossible to change in situ.

infrasilver · 15 Oct 2021

The bleeder is just to the left of the slave cylinder, there may be just enough room to get a lever in to lift it out?

Item 2 in the diagram.

MisterCorn · 15 Oct 2021

Let me know if anybody wants a photo of it.

MC

Shalmaneser · 18 Oct 2021

Thanks for the offer mistercorn - if you could have a poke at it to see if it's possible for it to become jammed I would be grateful!

From memory it's just a loose plastic cap in a hole...