Thread: Brake vacuum pump questions

Did the same job on my old D1 last Friday but did not completely remove that end cover, simply drilled out and replaced rivets one at a time with 5mm button head stainless screws an nyloc nuts, and no leak now. From memory the cover only houses the pump valves which are simple disc type so no need for lube there. Did you check the cam follower face, (inner end of pump actuator rod that runs on cam lobe) for damage to hard facing, i.e should be flat and smooth, this seems to be a potential problem area once the engine is getting up in age. I would apply a small smear of good quality engine oil to the face of the follower before replacement of the pump into the block.

Originally Posted by gazby

Did the same job on my old D1 last Friday but did not completely remove that end cover, simply drilled out and replaced rivets one at a time with 5mm button head stainless screws an nyloc nuts, and no leak now. From memory the cover only houses the pump valves which are simple disc type so no need for lube there. Did you check the cam follower face, (inner end of pump actuator rod that runs on cam lobe) for damage to hard facing, i.e should be flat and smooth, this seems to be a potential problem area once the engine is getting up in age. I would apply a small smear of good quality engine oil to the face of the follower before replacement of the pump into the block.

Did you bother with setting the engine to TDC on No.1 cylinder? I am planning on swapping my pump ths weekend as mine is also slightly leaking around the welsh plug as well as the end plate - a sign of impending failure... managed to source a genuine replacement for a reasonable cost from the UK... Just not sure how critical it is to set it up to TDC??
cheers,
Chookie
'98 300Tdi Disco

I had mine off a couple of times and never bothered with TDC, can't say it was too difficult to get it back in place however maybe a brand new pump has a bit more resistance in the plunger than an old one?
if you don't, just make sure you do a diagonal patten on the bolt tightening, so it bolts up nice and square!
bit of oil on the cam side sounds like a good idea too!

Chookie, I did not initially set engine on TDC but there was a fair amount of spring pressure on the bolts that hold the pump to the block, so as I loosened the bolts I rotated the engine to loosen the pressure on the pump push rod.
After removing the pump I turned the engine further to get the cam lobe turned away to the "back of cam" minimum lift position, this meant the bolts would enter the bolt holes and start with no pressure to re-fix the pump body to the block. My pump also gave the appearance that the plate body welch plugs were leaking but in fact were not, so good luck with yours.

Can't imagine how you got a drill in there Gazby, I could barely swing the spanner! Could see myself in the cam follower face, guess that's a good sign. Cheers for the advice re. oil. I've fixed the leak and get pretty good suction from it now but my brakes are still buggered :/ Might need to take a closer look.

Originally Posted by PJay

--- get pretty good suction from it now but my brakes are still buggered

Is your brake pedal hard while the car isn't stopping abruptly?

.

Sure is! Got some advice?
I pumped the pedal then turned the car on and the pedal went slightly softer and I could slowly press it further.
I read that it's possible when pads are worn (like mine are) and the brake oil reservoir is on min (like mine was) that under hard braking the reservoir could empty and suck air in. Was going to bleed the lines tomorrow and get some new pads asap!

Pat

PJay, you may have misunderstood, I DID remove the vac pump from the engine, the pump assembly was in my workshop bench vice whilst I was individually drilling out rivets and replacing them with the nuts and bolts.
As I am now old and no longer flexible I was unable to wriggle in there and drill the rivets with pump fitted to engine, which may be possible with a right angled air powered drill (which I do not have), like you I found it difficult just to swing the spanner in order to refit the pump and tighten the six bolts.