ALH vacuum pump leak and concerns

Joester

Vendor
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Aug 17, 2009
Location
St. Louis
TDI
2002 Golf TDI
I have a 2002 Golf 5 speed, and I'm doing some maintenance on it.

Among other things, I'm replacing the clutch because it was grabbing very badly, and I'm also replacing the seal on the vacuum pump as it was leaking oil.

I just got the clutch off, and now I realize that these two problems are probably related, and now I am concerned.

When I got the transmission off, there was a puddle of oil in the bottom of it, presumably from the vacuum pump leak. The oil leaks out of the pump, runs down the back of the head and block, and is able to seep between the engine and the transmission to contaminate the clutch.

I cleaned up the transmission, and I am going to get the flywheel resurfaced tomorrow. Now, I'm assuming that this is the reason my clutch went bad so early... it is only about 40k miles old... a South Bend stage 2 clutch kit.

Obviously I don't want this to happen again

I read this thread: https://forums.tdiclub.com/showthread.php?t=294417

and it seems like sometimes the leak is not from the gasket that seals vacuum pump to the head, but rather from the gasket that seals the two halves of the vacuum pump together. I replaced the former. I cannot tell form looking at the vacuum pump where the leak was from.

Has anyone else had experience with leaky vacuum pumps and how did you remedy it? I don't want to ruin another clutch with oil contamination.


Here's the options I believe that I have

#1: replace seal between vacuum pump and head (DONE) and hope for the best

#2: replace the seal between the 2 pump halves using a BRM oil filter o-ring as noted in the above thread

#3: RTV both sides of the metal plate between the engine and transmission to try to avert any oil that should leak down there

#4: RTV the seals on the vacuum pump to try to help with sealing

Any opinions or insight is appreciated, thank you.
 

PDJetta

Top Post Dawg
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Nov 6, 2003
Location
Northern Virginia
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'04 Jetta GLS TDI Pumpe Duce Platinum Grey w/ Leather
I tend to want to be darn sure whatever I do will fix the situation, so I would be inclined to replace the vacuum pump with a new one and use a new seal to mount it. If the dealer is the only option, 1stvwparts.com can save you about 40% over retail. Its Auburn VW and this is their internet sales arm.

An added bonus may be the vacuum nipple from the ALH vacuum pump may now have a screw in fitting and no longer be the swivel type that can get loose and leak. I know this was the case whan I replaced the tandem pump on my '04. (this pump houses both the vacuum pump and fuel feed pump for the unit injectors).

--Nate
 

Joester

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St. Louis
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2002 Golf TDI
bumping this for the morning. I don't know weather to take the 2 halves apart and risk a worse leak, or to just put it back on with the new o-ring and hope for the best.

If I have to buy a new one, so be it, but id rather try out the old one with a new o-ring and just keep a very close eye on it.


I just thought of a new idea. What If I just J-B weld all around the edges of the 2 halves? If I ever have to take it apart, I'll just get a new one. but I doubt I will ever have to take it apart and that would pretty much ensure no leaks form the 2 halves. It would be ugly, but its under the engine cover anyways.
 

Got Bearings?

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May 5, 2007
Location
SoCal
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2001 Golf GLS
bumping this for the morning. I don't know weather to take the 2 halves apart and risk a worse leak, or to just put it back on with the new o-ring and hope for the best.

If I have to buy a new one, so be it, but id rather try out the old one with a new o-ring and just keep a very close eye on it.


I just thought of a new idea. What If I just J-B weld all around the edges of the 2 halves? If I ever have to take it apart, I'll just get a new one. but I doubt I will ever have to take it apart and that would pretty much ensure no leaks form the 2 halves. It would be ugly, but its under the engine cover anyways.
Replacing it is cheaper than a new clutch... not to mention the time it takes to R&R a clutch.

Stop being cheap and get a new vac pump. What's your time worth?
 

Joester

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2002 Golf TDI
Replacing it is cheaper than a new clutch... not to mention the time it takes to R&R a clutch.
Stop being cheap and get a new vac pump. What's your time worth?

right, if I KNEW that the seal between the two halves was the problem I wouldn't even hesitate to buy a new one, but if that seal is not the problem I would just be wasting $140. What if I get a new one and it just leaks again? :eek:
 

Growler

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Nov 24, 2003
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Millersport, Ohio
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Schmutz, 2015 Golf Sportwagen DSG & Schnurren, 2001 Golf GL 2 door 5M
why not spend $5 on a BRM oil filter to get the o-ring and repair the existing vac pump?
 

Joester

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St. Louis
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2002 Golf TDI
why not spend $5 on a BRM oil filter to get the o-ring and repair the existing vac pump?
I could not tell by the thread if that was a legitimate fix. It seemed like many people's pumps continued leaking after that.

Does that BRM o-ring trick actually work?
 

Growler

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Schmutz, 2015 Golf Sportwagen DSG & Schnurren, 2001 Golf GL 2 door 5M
yes. it worked great on _Mattmans jetta. sealed the leak that was in that half of th evac pump quite nicely.. of course his has continued to leak from the head to vac pump seal area due to a nick in the head..

but the BRM o ring does work for a replacement on the vac pump halves.
 

Joester

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St. Louis
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2002 Golf TDI
I guess I'll give that a try and if that doesn't work I'l get a new vacuum pump. I'll also inspect the head for scratches when I get home.
 

Joester

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2002 Golf TDI
OK, so I JB-welded the 2 halves together today, and reinstalled with a new gasket between the pump and the head. I put a dab of Hondabond RTV over the crack where the cam cap meets the head as well. I inspected the mating surfaces and everything seems to be very smooth.

I apologize in advance for essentially ignoring everyone's advice here, I feel like its kind of disrespectful, but here was my thought process: J-B weld will pretty much guarantee no leak from between the 2 halves, so I can pretty much eliminate the possibility of a leak form there, something I cannot say had I replaced the o-ring with a BRM oil filter o-ring. I don't ever see myself needing to take the two halves apart, and if I ever do, I will just buy a new pump. JB weld doesn't look pretty but its under the engine cover anyways.

I will update this thread sometime in the future to weather or not this worked.
 

Joester

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2002 Golf TDI
I don't want to speak too soon, but it seems to not be leaking anymore! I've put about 100 miles on it and there's no leaks yet. Fingers crossed it stays that way.

See above post for what I did. Will update once I get more miles on it.
 

_MattMan

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Dec 29, 2011
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Lancaster, Ohio
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03 Jetta GLS Wagon 5sp
Are you positive it’s leaking at the pump half’s? It appears you may have a similar issue like mine where there is a knick or uneven surface area on the head where the pump seals.

During all my troubleshooting attempts, for grins I bought the BRM oil filter, used the seal from it, which I may add fit as promised. Thought it was the case but wasn’t long and the small leak returned.

I installed high temp gasket sealant between the head and the pump and that actually appeared to have worked but later a small leak started again.
I ended up installing a new pump and seal but discovered the gasket sealant I used appeared to have dried up so maybe I used the wrong stuff or applied it incorrectly but I went ahead and installed the new stuff.

I was told to apply the RTV to the pump / head area but to lightly tighten the part and to allow it to sit get tacky before fully tightening it down and let sit for a day.

From time to time, I have this habit of checking things over and last night during some maintenance I wiped in this area and may have noticed some oil again……… :eek:

If this is the case, I will let you know how my next step will go as it was recommended I use Permatex Ultra Copper Maximum Temperature RTV Silicone Gasket Maker Part# 81878.

http://forums.tdiclub.com/showthread.php?t=294417
 

Shawnz

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Apr 14, 2008
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Peoria, AZ (Phoenix)
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'02 Jetta GLS TDI, ex-O1M
Mine leaked at the outlet. I JB welded it on and it seemed fine. I didn't' want to have problems if the JBweld ever let go so I went ahead and got a new one from Bora Parts.

I have the one I JB welded I'll let go cheap if you want to give it a shot:

 

RedTDIowner

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Aug 24, 2004
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Crestwood KY
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2014 Audi A6 3.0 TDI
I was speaking with GotEuroCorrado today and I no longer think my vacuum pump is my problem. I upgraded to a rocket 3 chip at the TDIfest over a year ago and that is when I started noticing all this extra oil around the head, valve cover and vacuum pump. I had just assumed that it was my vacuum pump seal leaking again. Well GotEuroCorrado informed me that all that oil I am seeing might be from not having a catch can instead. I am going to install that next and see if it clears up the oil leak. Any suggestions on where to buy an inexpensive one that is easy to install/mount?
 

Joester

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Location
St. Louis
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2002 Golf TDI
I was told to apply the RTV to the pump / head area but to lightly tighten the part and to allow it to sit get tacky before fully tightening it down and let sit for a day.

This is exactly what did. Still leaked for me. The head on my car is a refurbished head from Frank06, the head that came on my car did not leak from the pump. I am by no means blaming my problems on Frank, by the way. Frank is a great guy.
 
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Nuje

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Feb 11, 2005
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Island near Vancouver
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2015 Sportwagen; Golf GLS 2002 (swap from 2L gas); 2016 A3 e-tron
To the above post: I have exactly the same symptoms. Got a replacement head from Franko6 and went from no leak at the vacuum pump to leak at the vacuum pump.

Any solution to this? I already put a brand new seal on the vacuum pump (haven't taken the pump apart as the leak certainly seems to come from the vacuum pump and/or valve cover interface.

If there is a small imperfection in the pump-to-head sealing surface, what's the best way to seal that?
(Please don't say "buy a new head"...)
 

darkscout

Grammar Scout
Joined
May 28, 2006
Location
Michigan
TDI
2003 Golf
Finally, a recent thread.

I'm having the same problem.

I finally have a clutch that will hold my tune and now I've been noticing more and more oil around the entire head cover. I wrapped my vacuum pump and CCV can each with a red rag and noticed the vacuum pump one had the most oil, although there is oil flung all over my engine bay.

Did GotEuroCorrado say where the extra oil was coming from? Is there more blowby because of the tune? I'm just worried because the last time I had a car that coughed up this much oil it was my 1.8L 1991 Jetta and it had a hole in the piston.

The only other observation I have at the same time is that under very hard accell the engine sounds like it's lugging (even if we're well out of lugging range), but if I back off of the accelerator the sound goes away. I was assuming I just needed a new set of motor mounts as the extra torque and it was my engine doing something funny with exhaust geometry.
 
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BobnOH

not-a-mechanic
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May 29, 2004
Location
central Ohio
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New Beetle 2003 manual
O.K., I'll play stupid here, just not getting it.
The vac pump is a simple gear driven pump driven by the end of the camshaft.
The pump housing can leak oil at the head/cover mating surface. New seal required.
The vac pump should not have oil in it. If it does it would come thru the shaft seal behind the plastic drive flange. Time for a new pump. And clean the oil out of the vacuum tubes.
 

RacerTodd

Veteran Member
Joined
Jun 28, 2007
Location
Kirkland, WA
TDI
2001 Golf TDI
O.K., I'll play stupid here, just not getting it.
The vac pump is a simple gear driven pump driven by the end of the camshaft.
The pump housing can leak oil at the head/cover mating surface. New seal required.
The vac pump should not have oil in it. If it does it would come thru the shaft seal behind the plastic drive flange. Time for a new pump. And clean the oil out of the vacuum tubes.
The pump is not gear driven. There is a slot milled in the back of the cam. The pump shaft has a raised "key" that fits into the slot.

In addition to the o-ring between the pump and head, there is another o-ring between the two halves of the pump itself.

The vacuum pump should always have oil in it. There is a small hole in the head that feeds oil into the pump to lubricate it. In the picture below, look at the black o-ring seal. See the round hole that the o-ring goes around? That's the oil feed hole.

 

fruitcakesa

Top Post Dawg
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Feb 18, 2007
Location
Vermont
TDI
04 jetta 5 spd wagon
The VP in the 02 has leaked for years and I have ignored it except to mop up the accumulating puddle of oil on the trans case. Time for repair.
I searched 1stvwparts website for the pump to head seal but could not find it.
Does anyone have a p/n?
 
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