How I deal with loose nipples...vacuum pump repair

WildChild80

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May 30, 2016
Location
Nashville, AR
TDI
2001 Jetta TDI 2000 Jetta TDI 2000 New Beetle TDI ALL 5 speeds
I've got one with circular scores in it that seems like a perfect candidate for an alternative repair or to learn it's not possible or worth the effort...

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Faster

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May 5, 2001
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Monument, CO
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1999 Jetta ALH, 2007 Specialized Roubaix
JETaah what JBWeld did you use? I see there are only about 600 varieties. I prefer the liquid type over the putty style personally.
 

apple4ever

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Location
Coatesville, PA
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2002 Jetta TDI, 5sp manual, 280K miles
I need to do this, as my nipple has been repair a bunch, but never very good.

Can you explain more about preparing the surfaces and the notches there?
 

Lenton

Active member
Joined
Nov 13, 2022
Location
Swindon
TDI
Golf plus 1.9tdi
Here is how I deal with the ALH's loose vacuum pump nipple problem. I have tried the peen-over method
and it works for a while but if it failed the first time then it probably will again. This will eliminate the o-ring's function that seals the joint. It seems like a weird failure prone, short term design to begin with and they keep doing it year after year.

I use JB Weld for this. It does take forever to set up....something like 10-12 hours to get firmed up.
This is a long time and maybe there is a shorter "kick-time" epoxy....I'm sure that there is but, this is my choice in this case. It is strong and the long set-up time lets it flow into crevices and level out. I wait overnight before putting the pump back into service.

Prepping the pump.

Clean the surfaces thoroughly with brake cleaner.

Create some tooth for the epoxy to "key" in onto the surface. I use a die grinder or Dremel to create small undercut notches on the 45* surface. The notches should be deep enough to hook the epoxy and prevent it from lifting up off the pump body. Finish off with a little rough Emery cloth on the bonding surfaces.



create a dam for the epoxy to settle in. I used 3/4" electrical tape here but, 1/2" is plenty and makes it easier to apply the JB Weld down into the trough.



Support the pump in a vice or other means so the the nipple is perpendicular to level. You will be relying on gravity to level the epoxy mix as it sets up.

Next, mix up some JB Weld. I have tried different ways to apply it and this one worked OK. Squirt both parts into a small plastic zip lock bag. A heavier weight bag is a good choice so that it does not break in the process. Seal the bag and squish it around until you get a uniform color. Nip the corner of the bag...just a small hole so that you can squeeze the mix out like a pastry bag dispensing icing.



Apply the mix first to the outer edge and drag a small tool like the end of a paper clip or a pick around the perimeter of the tape dam to work the epoxy down along the 45* edge.
Apply the rest to bring up the level about 3/32-1/8" above the surface of the nipple's flat.



After you have noticed that the epoxy has set up in the dispensing bag it is time to remove the tape. Trim off the edge with a razor while the epoxy is still semi-plastic.

Voila!:D

I Know this is an old thread but hopefully someone will reply. I have a BXE engine golf plus 1.9tdi 2005 and after changing literally everything in the turbo system. New turbo cassette, new egr, new actuator, new vacuum solenoid. I have managed to rid the black smoke and got the car to pass its emission and annual road test. The car now doesn't boost and isn't running as it should though its drivable. I found the dreaded loose, very loose nipple on the vacuum pump. Does this repair require the nipple to be pulled out as far as it can travel (as I did whilst on car with epoxy steel weld) or as I now suspect, pushed in as far as it'll travel? I'm assuming I've done the wrong direction and thus the O ring bypass effect of this repair is flawed. If as I suspect I've gone in the wrong direction, I'll have to find an eBay used part and swap it out. Be grateful for any clarification. Thank you in advance
 

JETaah

Vendor , w/Business number
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Location
mi 48836
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96 B4V, 1999.5 jettaIV,2005 BEW Beetle
I Know this is an old thread but hopefully someone will reply. I have a BXE engine golf plus 1.9tdi 2005 and after changing literally everything in the turbo system. New turbo cassette, new egr, new actuator, new vacuum solenoid. I have managed to rid the black smoke and got the car to pass its emission and annual road test. The car now doesn't boost and isn't running as it should though its drivable. I found the dreaded loose, very loose nipple on the vacuum pump. Does this repair require the nipple to be pulled out as far as it can travel (as I did whilst on car with epoxy steel weld) or as I now suspect, pushed in as far as it'll travel? I'm assuming I've done the wrong direction and thus the O ring bypass effect of this repair is flawed. If as I suspect I've gone in the wrong direction, I'll have to find an eBay used part and swap it out. Be grateful for any clarification. Thank you in advance
I did not think that this problem would be present on a tandem pump. Perhaps the pump that is used on a BXE is different from the ones used stateside.
Anyway, if it is loose, It should not matter if it was pushed in or pulled out as long as it is made rigid and seals the joint. I prefer to push the nipple inward against the seal and peening over the edge to take the slop out of the assembly before encapsulating it in epoxy. The epoxy will then prevent the joint from working loose due to vibration like it did originally.
 

Lenton

Active member
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Nov 13, 2022
Location
Swindon
TDI
Golf plus 1.9tdi
I did not think that this problem would be present on a tandem pump. Perhaps the pump that is used on a BXE is different from the ones used stateside.
Anyway, if it is loose, It should not matter if it was pushed in or pulled out as long as it is made rigid and seals the joint. I prefer to push the nipple inward against the seal and peening over the edge to take the slop out of the assembly before encapsulating it in epoxy. The epoxy will then prevent the joint from working loose due to vibration like it did originally.
Yeah seems a few different parts we have on euro specs to you state side. The vacuum solenoid for instance is 1 combined where as I am aware you guys have 2. something like an N18 and N75? And I'm not sure if my vacuum pump is a "tandem"? As you call it. It has a single nipple and looks similar to the ones on the mk4 though my car is a mk5. Did you guys have the Golf Plus? It's a larger Golf but not quite a SUV though again I believe it to be closer related to the Touran ( a small people carrier). Anyway thanks for the reply. My car isn't boosting and the vaccum pump is the only part not swapped out. I will do a vac test on it but if that seems OK, it's probably time I bit the bullet and got a mechanic to use the proper VW diagnostics to figure out *** is up.
 

JETaah

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mi 48836
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96 B4V, 1999.5 jettaIV,2005 BEW Beetle
A good test for our vac pump is to attach a vac gauge to the small nipple on the check valve (with brake booster attached and no cracks in the plastic tube) and do a reading, engine running. If it falls short of~ 25” vac push the nipple inward to compress the seal and see if it corrects the condition.
It should read a solid number with no needle bounce.
 

KrashDH

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Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
A good test for our vac pump is to attach a vac gauge to the small nipple on the check valve (with brake booster attached and no cracks in the plastic tube) and do a reading, engine running. If it falls short of~ 25” vac push the nipple inward to compress the seal and see if it corrects the condition.
It should read a solid number with no needle bounce.
The other thing to add to this is it should create full vac quickly, within a sec or 2. I had symptoms of the loose nipple and applied all the fixes and when I was testing it, it would pull vac but it took like 45 seconds or something. It wasn't the nipple but the internal pump components were worn out. New pump time.
 

Lenton

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Nov 13, 2022
Location
Swindon
TDI
Golf plus 1.9tdi
The other thing to add to this is it should create full vac quickly, within a sec or 2. I had symptoms of the loose nipple and applied all the fixes and when I was testing it, it would pull vac but it took like 45 seconds or something. It wasn't the nipple but the internal pump components were worn out. New pump time.
Very informative reply. Much appreciated. I'll get to it this week. My money is on a worn vac pump. Literally the turbo failure destroyed every changeable component and as that pump is the only thing not yet swapped out, its a certainty to be chewed up inside, like you said. Many thanks for your time.
 

JETaah

Vendor , w/Business number
Joined
Jan 18, 2001
Location
mi 48836
TDI
96 B4V, 1999.5 jettaIV,2005 BEW Beetle
Another thing to add is that if it does take longer than a couple of seconds to reach high vacuum then the small nipple on the check valve could be clogged. This happens a lot when there is a breach in the turbo actuator or any of the hoses and it has sucked in rust or road debris. It also can clog the N75 valve and the black and white check valve or cause the b&w check valve to no longer “check”.

And, if the brake booster has been disconnected from the in-line check valve it will take a few seconds more to evacuate the booster before the system reaches full vacuum. The in-line check valve works only on the brake booster. The small nipple is operating directly from the vacuum pump.
 

KrashDH

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Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Very informative reply. Much appreciated. I'll get to it this week. My money is on a worn vac pump. Literally the turbo failure destroyed every changeable component and as that pump is the only thing not yet swapped out, its a certainty to be chewed up inside, like you said. Many thanks for your time.
Well, a turbo failure shouldn't be able to make its way to the vac pump, at least the debris shouldn't. The inside of my pump wasn't chewed up at all. By the eye, you wouldn't be able to tell that there was wear. But it was enough for the pump not to create full vac.
 

Lenton

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Swindon
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Golf plus 1.9tdi
Well, a turbo failure shouldn't be able to make its way to the vac pump, at least the debris shouldn't. The inside of my pump wasn't chewed up at all. By the eye, you wouldn't be able to tell that there was wear. But it was enough for the pump not to create full vac.
Well there's what should happen when a turbo goes bonkers and what did happen. All I can say is that my turbo went bonkers and after rebuilding The egr diaphragm was busted as was the actuator diaphragm as was the vac solenoid. All stuffed. So thanks for your opinion but I'm dealing with facts. "chewed up" was just a figure of speech. But thanks. Its all simple info re the pump and gives me a nod in the right direction to test.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Well there's what should happen when a turbo goes bonkers and what did happen. All I can say is that my turbo went bonkers and after rebuilding The egr diaphragm was busted as was the actuator diaphragm as was the vac solenoid. All stuffed. So thanks for your opinion but I'm dealing with facts. "chewed up" was just a figure of speech. But thanks. Its all simple info re the pump and gives me a nod in the right direction to test.
Woah man, easy. Only trying to help. I mean, look where the vac pump is, how it draws vac and the diagram. I posted my above comment because I don't see any way debris is going to get in there and do damage. The turbo failure sucks, but the vac pump might just be a coincidence, I mean did you check it prior to this happening? It might not have been healthy to begin with. Sounds like you have enough information to progress troubleshooting. Good luck
 

Lenton

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Nov 13, 2022
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Swindon
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Golf plus 1.9tdi
As I've said, info on the question re vacuum pump are very appreciated and thanks for your time. As per queries to the over all issues, I've already worked through those and very happy the facts of those issues were as found. Have a great day
 

Lenton

Active member
Joined
Nov 13, 2022
Location
Swindon
TDI
Golf plus 1.9tdi
A good test for our vac pump is to attach a vac gauge to the small nipple on the check valve (with brake booster attached and no cracks in the plastic tube) and do a reading, engine running. If it falls short of~ 25” vac push the nipple inward to compress the seal and see if it corrects the condition.
It should read a solid number with no needle bounce.
Yeah it reads bang on a steady 25 so I'm happy my vac pump is running as should.
However when I test the hose feed to egr, it barely registers and the same to the egr cooler and the same for the actuator feed. I've tested all the hoses on hand vac and all hold vac. I have found my reservoir is not holding any vacuum. When I shake it, I can hear a rattle. I assume the internal nip has snapped. Anyway one is on order from ebay, so hopefully this will be the missing link. Thanks for pointing me in the right direction.
 

Lenton

Active member
Joined
Nov 13, 2022
Location
Swindon
TDI
Golf plus 1.9tdi
A good test for our vac pump is to attach a vac gauge to the small nipple on the check valve (with brake booster attached and no cracks in the plastic tube) and do a reading, engine running. If it falls short of~ 25” vac push the nipple inward to compress the seal and see if it corrects the condition.
It should read a solid number with no needle bounce.
Yeah it reads bang on a steady 25 so I'm happy my vac pump is running as should.
However when I test the hose feed to egr, it barely registers and the same to the . I've tested all the hoses on hand vac and all hold vac. I have found my reservoir is not holding any vacuum. When I shake it, I can hear a rattle. I assume the internal nipe has snapped. Anyway one is on order from ebay, so hopefully this will be the missing link.
 

JETaah

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Joined
Jan 18, 2001
Location
mi 48836
TDI
96 B4V, 1999.5 jettaIV,2005 BEW Beetle
The vacuum supply to the N18 EGR vacuum control valve should be whatever the vacuum pump is reading.
N18 valve output vacuum to the EGR diaphragm should be whatever is needed to make the MAF actual value match the requested value (see engine controller group 1 on VCDS). It usually takes about 10-12" to start popping the EGR valve open. It will vary since you are dealing with exhaust pressure helping to open the EGR valve and boost pressure on the intake side countering it.
 

Lenton

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Swindon
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Golf plus 1.9tdi
Euro spec no. N18. N75. We have some combined thing simply called a vacuum solenoid. It has 7 hoses running through it. But essentially it's the same thing. And yes I assume the 25 reading should be the steady number through the system. Like I say, I have a broken reservoir, so I am hoping this to be the cause. Otherwise I'm sorry, I don't really understand or follow your reply.
 

JETaah

Vendor , w/Business number
Joined
Jan 18, 2001
Location
mi 48836
TDI
96 B4V, 1999.5 jettaIV,2005 BEW Beetle
Euro spec no. N18. N75. We have some combined thing simply called a vacuum solenoid. It has 7 hoses running through it. But essentially it's the same thing. And yes I assume the 25 reading should be the steady number through the system. Like I say, I have a broken reservoir, so I am hoping this to be the cause. Otherwise I'm sorry, I don't really understand or follow your reply.
OK, your move. Let's see what happens when you correct the reservoir leak.
(y)
 

1975 Kombi

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A piece of bike tire tube, a washer and some mechanics wire. It does not move at all.
 

Dolcesails

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Sep 22, 2022
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Florida
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2014 vw jetta
Upon trying to fix my Turbo boost problem I came on to the nipple for the vacuum pump 1st off that hose was very loose so I replaced. It and found that the nipple was also loose. I JB welded it back in, put it all back together and it seems like the boost is better but then stops today I took the mass air flow sensor out cleaned it up with brake cleaner and install it back into the car. I haven't driven it yet. All my vacuum hoses look guess the next step is.?
 

JETaah

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Joined
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Location
mi 48836
TDI
96 B4V, 1999.5 jettaIV,2005 BEW Beetle
See if the check valve inside the vacuum pump is working consistently.
Put a length of hose on the pump's nipple (the one that you JBWelded) with nothing else attached to it.
Try blowing and drawing on it. If it does not shut tightly as you inhale the internal check valve is compromised. I have found that its condition can change as the engine warms up and can be failing when it gets up to engine operating temperature.
Without that check valve working you will not be able to create sufficient vacuum to operate the turbo actuator accurately.

At that point you may want to start off with a new vacuum pump or get creative and stick another check valve externally between the pump nipple and the hose that leads to the brake booster check valve.
 
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