TheSamba.com :: View topic - Cruise Control Pump: Replacements from other VWs?

Tue Apr 12, 2011 9:13 pm

Anyone know what other VW models cruise control vacuum pumps are a direct-swap replacement for the stock Vanagon one? (I suspect someone with EKTA could answer this quickly :))

Also, a part number for it would be helpful. This is for an '88 AT Westy.

Tue Apr 12, 2011 10:36 pm

ALL VAG products of the same era used the same pump. Bracket might be different but the pump is the same.

FYI: the pump is infrequently bad.

Wed Apr 13, 2011 12:30 am

Here's a list of all the VW/Audi cars it was used on.

They're still available from VW at £130.79 plus v.a.t!

MG

Wed Apr 13, 2011 10:30 am

I did replace an electric motor on a vaccuum locking device on a Polo.

Usually,you can open them and replace just the motor and seals.Easy and cost effective 8)

Wed Apr 13, 2011 3:07 pm

Yeah, I think the seals in mine are shot - when the pump stops running, vacuum slowly goes out, even before the vent valve clicks. Thanks, SycnroGhia - I've procured from eBay a 95 Passat one that should work. I'll probably bench dismantle mine once

Thu Apr 21, 2011 1:26 pm

mariusstrom wrote: Yeah, I think the seals in mine are shot - when the pump stops running, vacuum slowly goes out, even before the vent valve clicks. Thanks, SycnroGhia - I've procured from eBay a 95 Passat one that should work. I'll probably bench dismantle mine once
Ok, new pump arrived yesterday and would appreciate people's thoughts on this. The new pump behaves exactly the same as my old one. I opened mine up and made sure the seals on mine are good.

When I run either pump (close vent valve and apply 12V to the pump), you can see the regulator cinching up as vacuum comes on... but not enoguh vacuum happens to pull the regulator in.

So, I plug in my trusty Harbor Freight hand-operated vacuum pump, and tie into the vacuum line where the motor does. Cinches the regulator right up and holds vacuum just fine. So, I'm saying the entire vacuum system works fine.

I'm not sure what to do next. All the Bentley cruise control tests work out. I'm wondering that, since the vacuum motor won't move the throttle, is there something to do with the throttle being too-hard-to-move?

Thu Apr 21, 2011 1:32 pm

Maybe the pump is good but there is a vacuum leak somewhere in the system- similar to sucking on a straw with a hole in it. Don't forget to check for leaks at the shut off switches for the clutch/brake pedal.

Thu Apr 21, 2011 2:26 pm

syncrodoka wrote: Maybe the pump is good but there is a vacuum leak somewhere in the system- similar to sucking on a straw with a hole in it. Don't forget to check for leaks at the shut off switches for the clutch/brake pedal.
I don't believe it's that. Rationale is that putting a hand-pump in place of the CC pump and pulling vacuum works fine - and the system stays sealed up for a good time (let it sit for 5 mins and it held). Pushing the brake immediately drops the pressure out.

Is my thinking right?

Thu Apr 21, 2011 2:43 pm

Quote: Cinches the regulator right up and holds vacuum just fine. So, I'm saying the entire vacuum system works fine.
I didn't read this right. It sounds like the system is working correctly

Thu Apr 21, 2011 2:59 pm

syncrodoka wrote: Quote: Cinches the regulator right up and holds vacuum just fine. So, I'm saying the entire vacuum system works fine.
I didn't read this right. It sounds like the system is working correctly
Yep, but only with the vacuum hand-pump. Both cruise control vacuum motors I've tried can't cinch it up to move the throttle lever, so I'm wondering if my problem is actually with the throttle lever.

Fri Apr 22, 2011 12:49 am

If you have a multimeter check to see that you got the correct power to the vacuum pump.

Not to steal the thread but while on the subject of cruise control, does any know where I can get an actuator, mine is broke and only a complete system in the classifieds.

Wed Apr 27, 2011 11:32 am

87vanagon wrote: If you have a multimeter check to see that you got the correct power to the vacuum pump.

Not to steal the thread but while on the subject of cruise control, does any know where I can get an actuator, mine is broke and only a complete system in the classifieds.

You can get the actuator (rubber plenum) from other VWs probably listed above. I have found them on Jettas but the bracket is different and the little arm that connects to the throttle body also. You will have to swap over the bracket and connecting arm.

I just put CC in my friends van last night and we are having the same problem as mariusstrom. If you ground pin 4 on the computer connector, the pump comes on and the plenum starts to shrink but not enough. If you suck on the hose going to it, it holds vacuum and shrinks all the way. We have tried two different pumps also. We are not currently connected to the pedal switches because we didn't have a long enough hose to go up to the front, so it can't be a leak from front to back. We assumed that the vacuum switch on the brake pedal was redundant since the wiring from the brake light switches goes to the computer and tells it that the brakes are on.

Wed Apr 27, 2011 5:18 pm

When you ground #4, you should also ground #7 to close the valve in the pump. I assume you plugged that hose at the pump (the other end leads to the brake and clutch vent valves which you disconnected) and that is why you didn't need to worry about pin 7?. Just checking. Someone reported sucking water through the pump for several seconds and then letting it pump it all out and their suction went from 3hg to 14 or something. To me, the diaphram seems to need a lot of force to pull the throttle, but surprisingly that litttle pump does it quickly.

Thu Apr 28, 2011 3:33 pm

davevickery wrote: When you ground #4, you should also ground #7 to close the valve in the pump. I assume you plugged that hose at the pump (the other end leads to the brake and clutch vent valves which you disconnected) and that is why you didn't need to worry about pin 7?. Just checking. Someone reported sucking water through the pump for several seconds and then letting it pump it all out and their suction went from 3hg to 14 or something. To me, the diaphram seems to need a lot of force to pull the throttle, but surprisingly that litttle pump does it quickly.
I opened a pump the other day, and I can't imagine that running water through it is a good idea at all. Lots of electronics and coils in there, I think water would kill it.

Thu Apr 28, 2011 3:45 pm

I see your point, but I read about it here and it sounded good so I tried it. It didn't seem to hurt the pump.

http://20v.org/cruise.htm
"If your throttle doesn't move but your pump runs and you have no vacuum leaks, read on. If you have a Mity-Vac or a vaccuum gauge, you can get a numerical value for the pump. A year or so ago, my pump worked fine. This time around it drew 3 inches Hg. I disconnected the hoses, and connected a line to the air intake (the larger black port). I also connected a return line to the exhaust port (the stubby white one under the intake). I plugged the vent port with my finger, stuck the intake hose into some water, and applied power for 3-5 seconds. After this I ran it disconnected to flush the water out. After the flush I got 17 inches Hg out of the pump. I can't guarantee if there are any long term negative effects of this method, but it saved buying a new pump in the short term. (Six months later it still works) "

Sun May 10, 2020 9:11 am

Resurrecting a dead post, but this one is open ended and I have some new input. I’m in the same situation as another poster where the pump works, the pump valve actuator works, yet I still have no cruise control. The van passes the whole Bentley troubleshooting chart, and it not ready to narrow it down to the cc unit. I suspect the vacuum pump is not functioning properly. When I plug my mityvac in to the vacuum system it checks out with no leaks from the pump forward. So, per the troubleshooting steps, I bridge pins 7(vacuum pump actuator) and pin 4 (vacuum pump motor) to ground separately so I could verify that they were each operating as expected, and got no measurable vacuum. I measured first at the vent valve on the pedal cluster, and second directly at the pump. When I measured directly at the pump, there was an initial spike of about 5hg and then a rapid decline. I think it’s worth mentioning that my pump sounded very unhealthy. After running it with the hose unhooked for a while, it got a little better.

In the link to 20v.com above(which is dead, I had to google) the author says the pump was cleaned with water and got 14hg. This begs the question, how much vacuum is required to hold the throttle in place? It doesn’t need to be strong enough to move the throttle. That’s what your foot is for. I put hose clamp pliers on the section of hose heading to the cab, connected my knock-off mityvac w/ guage in place of the pump, actuated the throttle with my hand, and slowly pumped. I found that the bellows will stay in some place with about 4 inHg (+/- 1 for gauge accuracy).

At this point, I’m pretty confident that my pump is not doing it’s job, and I decide to take the risk. I get a large cup full of water, two small hoses, and hook em up to the vacuum pump. I placed the cup underneath the pump(removed from the bracket but still in the engine bay) and dunk the intake hose in the cup. The pump struggles for a bit, but continues to actuate slowly. I remove the hose from the cup as the pump struggled under the weight of this foreign liquid, and after a few seconds (which feels like an eternity) the pump clears. I let it run for a while to dry out. Feeling confident that nothing was going to fry, I repeated the process. I connected my gauge to the pump and find that it now quickly jumps up to 6 inHg and holds for a while, but still drops.

I added a few drops of Phil Wood tenacious oil to lubricate the seals and let the pump run a WHILE. The Phil wood oil is great stuff, but after those few drops hit the plunger inside, I could tell the pump was having to work pretty hard to distribute it. I think normal mineral oil would be fine, or maybe even better. After oiling, the vacuum does not drop. Checking the line going to the valve actuator at the pedal cluster, I get about 2, which should be enough to close the valve. As far as pump diagnosis and cleaning goes, I think it’s a success.

Sun May 10, 2020 10:56 am

i like to run soapy water thru the pump to clean out dust that accumulates in the chamber and seals. have done it on 3 vac pumps now with only good results, no harm. considerable dirt flushed out of two of them.

when troubleshooting, remove and plug at the engine compartment, the vacuum break valves from the clutch and brake switches to eliminate those troublesome lines.

Tue Dec 05, 2023 6:51 am

Here's a list of vehicles using the Vanagon cruise control vacuum pump. Info found @

https://www.jimellisvwparts.com/products/Volkswagen-VW/Jetta/Vacuum-pump/5284047/701907325.html