VW T4 Forum - VW T5 Forum banner
1 - 10 of 10 Posts

·
Registered
Joined
·
79 Posts
Discussion Starter · #1 ·
I replaced the vac pump couple of months ago for a cheap new one of evilbay and initially all was well. But now it's really noisy again, like camshaft and tappets worn, but it's defo the pump because pumping the brakes or disconnecting a vac line and the noises stop. I don't want to give stealers 250 quid for a gen one, only for it to go again. Does anyone out there know if it is possible to recon a pump yourself? What is causing these pumps to get so noisy?

The other thought I had was to install a vacuum reservoir with electric pump/sensor/switch and do away with the old pump altogether. I have read about land rover owners doing a similar mod and I know of other diesels with an electrically driven system as standard. Has anybody done this to a T4?
 

·
Registered
Joined
·
794 Posts
Funnily enough, mine has gone too.
Also a cheapo one off ebay. Am really annoyed.

I also wondered if it would be possible to fit something else. As the original is driven off the camshaft, I take it that it needs to be run at the same speed as the engine.
If so I dont know if an electtic one would. Perhaps a belt drive one could be fitted?
 

·
Registered
Joined
·
79 Posts
Discussion Starter · #3 · (Edited)
I thought about removing the drive rod and vac pump completely and fitting a blanking plate over the hole and then fitting an electric one somewhere else remotely. If I buy one of tidy t's induction kits I could remove the air filter box and make enough room to mount the new vacuum system down there out of the way. I need to do some more research but early signs are it not that difficult or expensive. By having a reservoir should always be enough vacuum and have electric pump switch on only when needed.

Am annoyed with ebay, keep making bad purchases and unlikely to get any redress when the seller is over in Poland! I'm happy in the respect that I finally know why the van is still so noisy. It runs quiet as a mouse when vac line to it disconnected.
 

·
Registered
Joined
·
3,185 Posts
I would have thought as long as the vacuum pressure is the same it would be OK to fit an electric system. But it would need to have a 100% duty cycle as your ECU needs it all the time through the N75 etc. It would probably have a small increase in engine power too as one less thing to clonk about.
 

·
Registered
Joined
·
79 Posts
Discussion Starter · #6 · (Edited)
Thanks for the input so far guys. I don't mind paying the £250 for a genuine vw one if it were going to be a permanent solution. However the evidence suggests these pumps are not up to the job. How long can a new one be expected to last before that awful tapping gradually comes back? I think an electrically driven system might be a cheaper and more reliable solution with the added benefit of reducing engine load like Tony says.

You can get adjustable sensors that would activate a relay to switch on the pump only when reservoir level dropped significantly, so I don't know if this would still mean 100% duty cycle or not. My EGR is already blanked and I'm having it deleted off the ECU when it gets a remap. So it will just be supplying brake servo and a couple of other minor bits. My vacuum gauge in the cab never moves unless the brakes applied so I don't think the demands from the other bits are much at all.

I reckon it would cost just over £100 to do it. £60 for pump, £30 for sensor and relay, not sure about a reservoir but it wouldn't be much. Trouble is I don't think the wife and kids are too pleased starting a new project when I haven't even fitted the furniture or eberspacher yet!!! I might just buy a new vw pump after all...
 

·
Registered
Joined
·
794 Posts
Guys, please see my other thread re N75 and N18, the N75 controls the turbo actuator and is not connected to the vaccum pump. The N18 controls the EGR and is connected to the vaccuum pump, but, if you have blanked your EGR off its irrelevant anyway.

Sorry, but its taken me weeks to get my head around which is which.
 

·
Registered
Joined
·
45 Posts
I changed mine today with one off ebay. i think it is a genuine one its got all the part numbers and stuff all over it (which were slightly different) now at idle it sounds sweet as a nut but going along at high revs or above 50mph it sounds harsh! could this be a turbo or egr problem do you think?! cheers
 
1 - 10 of 10 Posts
Top