ALH leaking vacuum pump

josh8loop

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Sep 15, 2009
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Vero Beach, Fl.
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2002 VW Jetta TDI Manual(performed 01M to 5-speed swap) - 183,000 miles and climbing!
josh8loop,
Any update...?
Mine's leaking, too....:>(
df
I'm not sure if mine is fixed or not- I have a leaky valve cover that tends to muddy the results. Maybe someone who has a good non leaky valve cover that has done the BRM "O" ring replacement method could chime in? I can say however that anything would have been better than the squared off, worn down plastic feeling "O" ring I removed though! In a couple weeks I plan to get my Valve cover leak sorted out, and realign my drivers side cam bearing cap(since it is slightly misaligned causing potential oil leak path) and I should know results shortly after that.
 

josh8loop

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Vero Beach, Fl.
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2002 VW Jetta TDI Manual(performed 01M to 5-speed swap) - 183,000 miles and climbing!
Yes, I do have an update but am affraid it is still not conclusive enough for me. I ended up removing the valve cover to replace it with another used one to stop the oil leaks coming from that area. While I was in there, I went ahead and loosened my cam bearing cap on the vac pump side and tried to get it straight-the previous owner had a head job done, and there was a small step on the side of the head where the vac pump seals that was slightly detectable with a fingernail. I straightened it out pretty good, and used some fine grit sandpaper on a flat block to ensure the whole vac pump sealing surface it totally flat. Unfortunately I still have a leak from some where. The valve cover oil leaks are pesky because they can travel making you think other things are leaking when they are not. I am fairly certain that my oil leaks are not coming from the vac pump seals, but with a leaky valve cover I cannot totally prove it. The Mcmaster Carr "O" rings I picked up are slightly undersized by .006"(74x2.85mm vs 74x3mm), but I believe they are close enough. The sure bet would be to go with a supplier that will give you a full 3mm thick O ring or the BRM oil filter "O" ring as mentioned above. FWIW
 
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_MattMan

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Dec 29, 2011
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Lancaster, Ohio
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03 Jetta GLS Wagon 5sp
Well, I am behind on positing my findings as it has been a long process of trying this or that. The replacement O-ring from the BRM filter appeared to be the fix but it wasn’t too long and the small leak was back.
At first I thought it might be my value cover gasket so I added some DIY gasket in that corner including in the corners of the cam bearing seals near vac pump.
Nope, still the same issue, so before trying to install my new vac pump I purchased from BoraParts, oh did I mention I did replace the vac pump seal twice. I took the vac pump off again, clean the surfaces, thought I saw a few nicks or scratches that could cause a leak so I added some DIY gasket around the entire vac pump only, reinstalled and started driving.
BINGO !! After several attempts at various tests, this one appears to have done the trick !!! So far to date 06/25/2012, no leak. When I get time I will post a few pictures of what I saw and what I ended up doing with hopes this might help someone like a lot of you have for me. Thanks everyone !!
 

josh8loop

Veteran Member
Joined
Sep 15, 2009
Location
Vero Beach, Fl.
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2002 VW Jetta TDI Manual(performed 01M to 5-speed swap) - 183,000 miles and climbing!
Well, I am behind on positing my findings as it has been a long process of trying this or that. The replacement O-ring from the BRM filter appeared to be the fix but it wasn’t too long and the small leak was back.
At first I thought it might be my value cover gasket so I added some DIY gasket in that corner including in the corners of the cam bearing seals near vac pump.
Nope, still the same issue, so before trying to install my new vac pump I purchased from BoraParts, oh did I mention I did replace the vac pump seal twice. I took the vac pump off again, clean the surfaces, thought I saw a few nicks or scratches that could cause a leak so I added some DIY gasket around the entire vac pump only, reinstalled and started driving.
BINGO !! After several attempts at various tests, this one appears to have done the trick !!! So far to date 06/25/2012, no leak. When I get time I will post a few pictures of what I saw and what I ended up doing with hopes this might help someone like a lot of you have for me. Thanks everyone !!

Yes, would be really nice to see some photos of what you found and what you did to fix it. I've had a heck of a hard time with mine!
 

_MattMan

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Dec 29, 2011
Location
Lancaster, Ohio
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03 Jetta GLS Wagon 5sp
Successful Repair

Sorry for the delay, here is a few photos of my confirmed successful repair. After replacing the pump seal twice with a new one, rebuilding the pump with no success. I purchased and was about to install a new pump when I took another look, saw a few knicks and thought, " What the heck, lets try the DIY gasket seal. So far to date, " No leaks ".

Hopefully this will help,

Engine Knick


Engine Fix


VacPump Knick


VacPump Knick


VacPump DIY Gasket Attempt
 

_MattMan

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Location
Lancaster, Ohio
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03 Jetta GLS Wagon 5sp
Well, it appears I spoke too soon, as of last night I noticed a small leak again and will start monitoring it more closely to see if the issue has come back !! Sorry guys, thought by chance I got lucky but I see I am joining a few that have been down this road seeing same results. Back to the drawing board.......:(
 

josh8loop

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Location
Vero Beach, Fl.
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2002 VW Jetta TDI Manual(performed 01M to 5-speed swap) - 183,000 miles and climbing!
Well, it appears I spoke too soon, as of last night I noticed a small leak again and will start monitoring it more closely to see if the issue has come back !! Sorry guys, thought by chance I got lucky but I see I am joining a few that have been down this road seeing same results. Back to the drawing board.......:(


Don't feel too bad, mine still weeps a bit also. I think it's has lessened though. You mentioned the nicks on the sealing surfaces. I went to the extreme of using some really fine grit wet/dry sandpaper attached to a straight block and wet sanded all vac pump mounting areas cautiously. I need to inspect it again to see how things look now and will try to report back.
 

oldpoopie

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Location
Portland Oregon
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2001 golf gl, 2006 jetta, 1981 ALH swapped rabbit pickup, 1998 beetle
Don't feel too bad, mine still weeps a bit also. I think it's has lessened though. You mentioned the nicks on the sealing surfaces. I went to the extreme of using some really fine grit wet/dry sandpaper attached to a straight block and wet sanded all vac pump mounting areas cautiously. I need to inspect it again to see how things look now and will try to report back.
When you removed that end cam bearing cap, did you place a small dab of rtv under the cap ends against the head? If you dont it can leak from between the head and cap.
 

MCR

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May 17, 2007
Location
Cincinnati, Ohio
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2003 Golf TDI
Anyone have an update on finding the proper O ring for a leaking vacuum pump? A guy in this thread says he has found one that works.

http://forums.tdiclub.com/showthread.php?p=4057074#post4057074
I went to buy an oil filter kit for the BRM engine, and was handed the same filter and O-ring set I get for my ALH engine.

And to be clear, there are two seals involved. There is a purpose-built molded seal that matches one of the seal grooves and then there is another seal groove that you can get the big filter o-ring to fit into. In this second case, you're putting a round o-ring into a not-round seal groove.

And full disclosure---I haven't done this yet. It sounds like you need one of the Permatex products and maybe a bit of luck. The clearance (on my ALH) is pretty tight. I stopped because I needed to acquire some tools or drain some coolant. I was hoping to get the tools. (I needed a very short 10mm socket, but I might just punt and drain some coolant.)
 
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runonbeer

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Austin, TX/Chapel Hill, NC
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you don't need to drain coolant or disturb the flange on the head at all. just pop loose the connector for the middle coolant GP and the pump will slip past the plugs.
 

_MattMan

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Dec 29, 2011
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Lancaster, Ohio
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03 Jetta GLS Wagon 5sp
*** STATUS UPDATE ***


I ended up replacing the pump and seal but in the process I noticed the DIY gasket I used appeared to have melted or dried up so maybe I used the wrong DIY gasket sealant. I went ahead and installed the pump and seal any way.

Since all of this and several thousand miles and months later, last night during some maintenance (Creature of habit) I wiped in this area and may have noticed some oil again………

It appears to be in the same area so that means it’s got to be a surface issue on the head.

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

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.

Here we go again, fix, test mode, track and report - ….geeezzzzz:eek:


By the way, during all of this I never once had to disconnect or drain any fluids, besides having the need for a angled (Offset) boxed end wrench, the job is pretty straight-forward.:D
 

josh8loop

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2002 VW Jetta TDI Manual(performed 01M to 5-speed swap) - 183,000 miles and climbing!
When you removed that end cam bearing cap, did you place a small dab of rtv under the cap ends against the head? If you dont it can leak from between the head and cap.
Can't remember if I did that or not. I know I loosened the cam bearing end cap to realign so the vac pump to head/cap bearing cap mating surface was as flush as I could get it. Then I followed that by using some really fine sandpaper to ensure the entire sealing surface was true. Come to think of it, I'm not convinced I did add sealant to the bottom section of the cam bearing end cap. Drat! At least the oil leak is at worst annoying(just some oily wetness) and certainly doesn't demand immediate action.
 

_MattMan

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03 Jetta GLS Wagon 5sp
If my leak dide come back :mad:, its so small that is not worth loosing any sleep over. :D Although its going to bug me if I can't stop it as it's getting my clean engine dirty. :rolleyes:
 

josh8loop

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Vero Beach, Fl.
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2002 VW Jetta TDI Manual(performed 01M to 5-speed swap) - 183,000 miles and climbing!
Here is a question...Last night I was looking at my engine and noticed that my vacuum pump nipple was wet with oil and looked like it misted onto the valve cover allen cap screw. In my repair job of the vacuum pump I used a ball peen hammer to gently tap the aluminum down onto the nipple base to help stabilize it mechanically followed by cleaning and application of UltraGrey RTV to seal air from getting in. This is a vacuum port not pressure port. Why the heck would oil mist come from there?
 

thurgood

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Dec 5, 2012
Location
Cornelius, NC
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2003 Jetta Wagon
After reading this thread I decided to go after my vacuum pump oil leak. If you attempt this repair, please take the time to validate your vacuum pump performance before attempting to drive your car. I installed the o-ring that came from a Mann filter kit for my ALH (which measured approximately 3.35mm) and went for a drive only to find that I've lost enough vacuum to properly operate my brake booster.

When I got home I connected the vacuum gauge and was only measuring about 12.5" Hg at idle directly off the pump to eliminate other common leakage points as a source of low vacuum readings. I tried sealing the outlet (or is it inlet?) connection on the pump after reading several threads on here about failures at that location with no change in performance (JB Weld first, then UltraGrey RTV) the second time.

I took my vacuum pump back apart and reinstalled the original o-ring which was flattened and compression set along with some Loctite gasket eliminator. It measured between 2.15 and 2.20mm. I figured at this point it was either going to work or I was going to have to buy a pump, so I'll give it a try - I'd rather have a pesky oil leak than insufficient vacuum to drive my car.

With the old seal installed vacuum was back up to ~24" Hg at idle. It appears that the seal was too thick which caused bypass flow around the sides of the pump vane. It definitely looks like I didn't get the pump halves tightened appropriately when the ALH o-ring was installed, either due to being afraid of stripping the threads in the casing or because the o-ring was too thick.
 

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
Having a similar problem: Replaced the head and of all the things I thought I'd be challenged by/with, a leaking vacuum pump was not among them.

Mine sounds a lot more severe that what people are reporting here, though; mine is almost spitting an oily mist - like drive it around the block and I have a little puddle of oil sitting in the little corner formed by the vacuum pump/head junction facing frontwards.

After trying buying a new seal, replacing that with the old seal, putting RTV around the perimeter and still having the same problem, I was cleaning out the channel on the VP in which the seal lays and I noticed a tiny little scratch that turns out to be almost a "nick" - like with a fine pick, you can feel that there's a bit of depth to the "scratch".

Being that it's in the area of where I get the leak (2pm if you're looking at the vacuum pump surface that mates to the head, where you lay in the seal), I'm really hoping that's the issue (although, at $250 for a new VP, I'm not all that happy about it); to test my theory, I put some RTV into the little nick (it's maybe 0.2mm long maybe 0.1mm "deep" (if that)), then put the seal back in am gonna let it sit for a day and see if it at least changes the symptoms (hopefully for the better).

If nothing else, I felt better identifying what the issue is/was (if indeed, this is the case), because I was starting to go nuts trying to figure out what the
 

Nuje

Top Post Dawg
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Oil gallery plug? To quote a famous (or any) Frenchman, Qu'est-ce que c'est?
(What's that?)
 

Nuje

Top Post Dawg
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2015 Sportwagen; Golf GLS 2002 (swap from 2L gas); 2016 A3 e-tron
Oil galley plug is present and accounted for, plus, the leak is coming from the top part of the vacuum pump - see photo.

That's after running maybe 5 minutes - pooled oil already. :(
Holding a clean rag at that area, it's spitting from where the arrow is pointing. Everywhere else around the circumference is perfectly dry and clean.
Quick review of what I've got and what I've tried:
- vacuum pump didn't leak when I took it off
- why did I take it off? initially to do timing belt, then discovered lifter damage so replaced head
- which means, this isn't an OE head, but rather, a replacement head (AMC, I believe) from Franko6
- new seal(s) (currently on the third one of those)
- RTV under the bearing cap
- RTV under the valve cover - at corners of bearing cap, as well as all the way around the top
- different valve cover (used)
- different vacuum pump (also used)

Being that it's so isolated, I'm thinking is has to be related more to the valve cover/bearing cap junction than the vacuum pump....but I'm out of ideas as to what to try next. I'll spend the money on a new valve cover if necessary, but being that it leaks exactly the same, regardless of which valve cover or vacuum pump I've tried....?

Help?
 

oldpoopie

Vendor
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May 14, 2001
Location
Portland Oregon
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2001 golf gl, 2006 jetta, 1981 ALH swapped rabbit pickup, 1998 beetle
Yep! Also you can try and take off the vac pump to hold a good straight edge against the side of the head. The bearing cap should be exactly in line all the way to its top with the edge of the head. If it's not I'm afraid it's a problem with the head
 

Nuje

Top Post Dawg
Joined
Feb 11, 2005
Location
Island near Vancouver
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2015 Sportwagen; Golf GLS 2002 (swap from 2L gas); 2016 A3 e-tron
Thanks guys. I've re-seated the bearing cap three times now (a bit more RTV each time) and it doesn't really seem to affect the symptoms.

I've only been looking at the seam that the bearing cap creates with the head and that's perfectly flush, but hadn't thought to consider the vertical line it creates. Brand new head from Franko6, so I hadn't considered that to even be a possibility.

With that said, of course, in the absence of anything else....maybe that indeed is it (?).
 
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