Leaky vacuum pump fix

CanadianALH

Veteran Member
Joined
Aug 21, 2023
Location
Canada
TDI
2002 Jetta 5spd 2006 Jetta DSG (wifes)
So after doing some trouble shooting with my boost coming on late after @burpod had mentioned that in my logs. I tossed the ole Mitty vac on and lo and behold it was making 8hg at the brake booster. I then could hear it actually leaking at the pump. So because it was late in the day and I didn’t really want to pull the pump off I decided to do a little quick fix. First thing I did was a little research and there is a method where you clamp the nipple and pean it over to keep the seal compressed. And the jb weld seal which is a great idea but I didn’t have time for. I went to my local auto parts store and found some two part sealant stuff I used to patch a muffler one time. It’s good to 500C so I figured it was good. The package says it hardens like steal in 15 and is fully cured in 1hr which is my kind of time line. I used a clamp to compress the nipple so the seal was doing what it should. Ruffed up it up with a little sand paper and then I applied that stuff around it to both hold the nipple and seal it thus combining both methods. Tested it again today after sitting in the -22 something the last couple nights and I am very happy to report that it holds 25hg no problem which is what it should be adjusted for my altitude. I will report back in a few months and give a longevity update.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
So after doing some trouble shooting with my boost coming on late after @burpod had mentioned that in my logs. I tossed the ole Mitty vac on and lo and behold it was making 8hg at the brake booster. I then could hear it actually leaking at the pump. So because it was late in the day and I didn’t really want to pull the pump off I decided to do a little quick fix. First thing I did was a little research and there is a method where you clamp the nipple and pean it over to keep the seal compressed. And the jb weld seal which is a great idea but I didn’t have time for. I went to my local auto parts store and found some two part sealant stuff I used to patch a muffler one time. It’s good to 500C so I figured it was good. The package says it hardens like steal in 15 and is fully cured in 1hr which is my kind of time line. I used a clamp to compress the nipple so the seal was doing what it should. Ruffed up it up with a little sand paper and then I applied that stuff around it to both hold the nipple and seal it thus combining both methods. Tested it again today after sitting in the -22 something the last couple nights and I am very happy to report that it holds 25hg no problem which is what it should be adjusted for my altitude. I will report back in a few months and give a longevity update.
Looks like it should hold. Just keep an eye on it, lots of vibration. I peened my old one over like you except I went the copper RTV route for the outer seal, for flexibility and temperature (didn't want to risk cracking). My issue wasn't solved though because it still wouldn't pull vac, due to actual worn out internals
 

CanadianALH

Veteran Member
Joined
Aug 21, 2023
Location
Canada
TDI
2002 Jetta 5spd 2006 Jetta DSG (wifes)
Looks like it should hold. Just keep an eye on it, lots of vibration. I peened my old one over like you except I went the copper RTV route for the outer seal, for flexibility and temperature (didn't want to risk cracking). My issue wasn't solved though because it still wouldn't pull vac, due to actual worn out internals
I didn’t even pean it lol. Just clamped it and used that stuff. Yes that vibration is my only fear. I will be definitely reporting back. I called vw today and it’s $640 for a new pump so the next fix will be to the junk yard to find the least wiggly one.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
I didn’t even pean it lol. Just clamped it and used that stuff. Yes that vibration is my only fear. I will be definitely reporting back. I called vw today and it’s $640 for a new pump so the next fix will be to the junk yard to find the least wiggly one.
I bought a new Pierburg from Cascade years back after my OEM went kaputz.


Hasn't had any issues.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
That’s reasonable! That’s the next play then.
If you look closely too, the nipple is an integrated part of the design, so it can't "loosen" again. Really the only thing that would kill this pump is a manufacturing defect or worn internals
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
keep your old pump. you could probably do an easier more permanent fix on it "on the bench" and taking it apart, most likely the internals are perfectly good it's jsut that idiotic nipple design...
 

CanadianALH

Veteran Member
Joined
Aug 21, 2023
Location
Canada
TDI
2002 Jetta 5spd 2006 Jetta DSG (wifes)
keep your old pump. you could probably do an easier more permanent fix on it "on the bench" and taking it apart, most likely the internals are perfectly good it's jsut that idiotic nipple design...
Yes. I’m going to wait to see if it starts leaking again. If it does I’ll either order a new one or pull the old one off and do a more permanent fix. For now I’m happy. It is honestly the dumbest designed thing. Some stuff on this car is awesome other stuff makes you wonder.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
keep your old pump. you could probably do an easier more permanent fix on it "on the bench" and taking it apart, most likely the internals are perfectly good it's jsut that idiotic nipple design...
The only thing you can do by taking it apart is replace that o ring. There's a cross section of the pump somewhere on the forum. There would be no repair you could do from the inside.

Here's that thread with the photos:

 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Did the same, then hammered around the outside-edge and now get a steady 28hg
Hammering around the outside edge would be "peening", would it not? The whole idea of the peening method is to used the curved, tapered surface to "seat" the 2 piece nipple down onto the square o-ring that's in there to make a better seal.
 

braddies

Veteran Member
Joined
Jul 26, 2021
Location
America
TDI
03 golf ALH
Hammering around the outside edge would be "peening", would it not? The whole idea of the peening method is to used the curved, tapered surface to "seat" the 2 piece nipple down onto the square o-ring that's in there to make a better seal.
Yes "peened" that edge in, but first slathered some rtv in there and let it set for a bit before peening, so there should be a bit of rtv underneath that peened lip.
I think the clamp is key to this procedure anyway you do it for the internal o-ring to seal
 

golfclub

Well-known member
Joined
Feb 11, 2014
Location
Victoria B.C.
TDI
2000 TDI Golf
What I did recently and am very happy with is this.
I found a metal washer that would fit over the nipple. I cut a rubber washer from
a inner tube to also go over the nipple. To pull them tightly down and seal the joint,
I cut a hose clamp into two pieces and pop riveted it to the washer. The clamp was big
enough to slip over the pump body. Then just tightened up the clamp.
Did not have to remove the pump and the reading was over 29 Hg.
There was another thread where someone did a similar thing , but used wire to hold
the washer down. The clamp is more positive and looks better.
 

CanadianALH

Veteran Member
Joined
Aug 21, 2023
Location
Canada
TDI
2002 Jetta 5spd 2006 Jetta DSG (wifes)
What I did recently and am very happy with is this.
I found a metal washer that would fit over the nipple. I cut a rubber washer from
a inner tube to also go over the nipple. To pull them tightly down and seal the joint,
I cut a hose clamp into two pieces and pop riveted it to the washer. The clamp was big
enough to slip over the pump body. Then just tightened up the clamp.
Did not have to remove the pump and the reading was over 29 Hg.
There was another thread where someone did a similar thing , but used wire to hold
the washer down. The clamp is more positive and looks better.
Can you please post a picture of this? This sounds like a awesome idea
 

Nevada_TDI

Top Post Dawg
Joined
Aug 17, 2008
Location
Reno, sort of...
TDI
2001 Jetta TDI
If the problem isn't just the nipple, IIRC, a 72.5mm x 0.5mm O-ring should fix the seal inside.
I have repaired two in the past this way.
 

CanadianALH

Veteran Member
Joined
Aug 21, 2023
Location
Canada
TDI
2002 Jetta 5spd 2006 Jetta DSG (wifes)
Lol I was confused too, but now that you explained it I went back to read Nevada's post, and it now makes sense 😂
Didn't notice the first part:
Lol now I see that! Less confused too. So far I think my fix has worked. But with the freezing temps we are having I can’t be bothered to be outside let alone standout there looking under the hood of my car. I will fire it up this afternoon though and run it up and down the highway to get her a little warmer
 

J_dude

Veteran Member
Joined
Jan 9, 2020
Location
SK Canada
TDI
2003 1.9l “Jedi”
Lol now I see that! Less confused too. So far I think my fix has worked. But with the freezing temps we are having I can’t be bothered to be outside let alone standout there looking under the hood of my car. I will fire it up this afternoon though and run it up and down the highway to get her a little warmer
No kidding, it's -34 right now and I had to run over to the store for water and get the mail, truck hardly wanted to start and it was plugged in! It's been so mild I forgot what winter was actually like 😬😬😬
 

CanadianALH

Veteran Member
Joined
Aug 21, 2023
Location
Canada
TDI
2002 Jetta 5spd 2006 Jetta DSG (wifes)
We have been spoiled this winter lol. So cold this morning the 2006 felt like it was on race springs felt every bump in the road.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Lol now I see that! Less confused too. So far I think my fix has worked. But with the freezing temps we are having I can’t be bothered to be outside let alone standout there looking under the hood of my car. I will fire it up this afternoon though and run it up and down the highway to get her a little warmer
Should be fine, unless there is enough movement to crack the epoxy. No need to check it too often, if it fails, you'll know.
 

Shiboxtdi

Veteran Member
Joined
Dec 17, 2023
Location
Indiana
TDI
2003 VW JETTA ALH TDI (SOLD)
What are symptoms of a bad vacuum pump and can a vacuum leak have the same symptoms?
 

braddies

Veteran Member
Joined
Jul 26, 2021
Location
America
TDI
03 golf ALH
What are symptoms of a bad vacuum pump and can a vacuum leak have the same symptoms?
If you hook a vacuum gauge (miti-vac) to the side of the first check valve after the vac pump, that will give you a number for the actual amount the vac pump is pulling.
To your question, the symptom you'd be looking for would be less than 29Hg, or pulsing
 
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CanadianALH

Veteran Member
Joined
Aug 21, 2023
Location
Canada
TDI
2002 Jetta 5spd 2006 Jetta DSG (wifes)
I thought the minimum was supposed to be 25"
Depends on your altitude and stuff. I can only get mine to pull like 25-27. Plus how good is your gauge. But you can tell when your pump is leaking. I could hear mine and it was pulling like 8”.
 

KCCats

Veteran Member
Joined
Nov 20, 2008
Location
North Central IL
TDI
03 Jeta Wagon
To fix my pump I just pressed it back in and took a drift pin and Pinned it all the way around
Worked perfectly!
Did not however help my lag
 

J_dude

Veteran Member
Joined
Jan 9, 2020
Location
SK Canada
TDI
2003 1.9l “Jedi”
Depends on your altitude and stuff. I can only get mine to pull like 25-27. Plus how good is your gauge. But you can tell when your pump is leaking. I could hear mine and it was pulling like 8”.
Was under the impression that 29+ is optimal and less than that might work fine but might indicate a vac pump that has worn out a little bit.
Ok, but it's all dependant on elevation. Absolute vacuum is 29.92" at sea level, so unless the pump is brand new and you're at sea level, you will probably never see a TDI pull more than 28-29 under ideal conditions.
Telling people less than 29" is a symptom of a weak or leaking vacuum pump is misleading.

My car, at an elevation of a little over 3000 feet, pulls 26.5"hg, verified with two different gauges.
Maximum attainable vacuum at my elevation is 26.8, so I think we're good. 😉
 
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