Thread: vacuum pump oil leak

Covered lots of times.

http://www.aulro.com/afvb/discovery-...-oil-leak.html

Dave

Simple DIY job. Took me a few hours and I'm a slow worker. Apart from the obvious of resealing and tightening with bolts, I also used 2 gaskets against the block. It's been suggested this increases the life of the pump. For the price of a second gasket, I reckon it's worth while.

I have the same leak and its not stopped by the diy repair linked above, i think that little circular cap needs to epoxied or something as it looks like a small welch plug thats pressed in.

Originally Posted by Judo

Simple DIY job. Took me a few hours and I'm a slow worker. Apart from the obvious of resealing and tightening with bolts, I also used 2 gaskets against the block. It's been suggested this increases the life of the pump. For the price of a second gasket, I reckon it's worth while.

Yep, at least 2 gaskets, bolt

Originally Posted by loanrangie

I have the same leak and its not stopped by the diy repair linked above, i think that little circular cap needs to epoxied or something as it looks like a small welch plug thats pressed in.

Did you take the pump apart, remove the o-ring and reseal with silicone?

Originally Posted by Judo

Did you take the pump apart, remove the o-ring and reseal with silicone?

The guide i used at the time and those read since dont mention anything about the oil seal or resealing it or using 2 gaskets, might have to take it out and re-do.

I have seen some comments from people who drilled out the rivets one at time and replaced with bolts without taking anything apart and it stopped the leak. Great if that works, but my view is that's only doing half the job.

Turns out I have previously unseen photos of the work too.

The pump showing rivets, ready for operation.


Drill out rivets and clean up surface so it's flat for when the bolts go back in.


Lift off cover and you can see the o-ring. My o-ring section was quite flat. No wonder it was leaking. If there was replacement o-ring, I imagine that would fix it too, however it's actually a 1 piece custom 3 circle seal, so you can't use normal o-rings. Maybe I should stop calling it an o-ring...


RTV silicone and place cover back on with bolts. (I used spring washers as well. Could prob use nylocks too).


I also used 2 gaskets where it joins to the block.

I did this fix on my previous vacuum unit. when I took it apart I found a few bits loose inside (valve bits?) and had no idea where they should go back. Out of need I did reassemble with nuts and bolts and it still worked, but because it was also still leaking out of the welch plug I got a whole new unit.

The base problem with the Wabco units seems that the rivets just can't stay tight with the constant pounding they get. The rivets are a softer metal than in stainless fittings. So, when I got the new unit, before even fitting it drilled out and replaced all the rivets with new M5 bolts with washers and nylock nuts. Did the fitiings one at a time so as not to break the factory seal - I would see this as the only exception to cracking it completely and resealing. It's been good since I fitted it nearly a couple of years ago.