Water pump O-ring leak... Again

[Lasershark]

So I got a b7 A4 not too long ago. Had oil filter housing leak, fixed that. Had a stuck thermostat, fixed that. I did not know the history on the car so I got a new water pump/timing belt from a local audi shop and replaced those. It seemed simple enough, until the water pump started leaking.

So I got a new o-ring (oriellys), pulled the water pump back off and super cleaned the water pump mating area. I got about 100 leak free miles and sure enough the stupid thing started leaking again.

Reading that autoparts store o-rings might not be as good as quality as oem; I just picked up a new o-ring from the dealer and I am going to pull this stupid thing apart for the third time in a month!

The first time I did not lubricate the oring, I read somewhere not to.
The second time I did lubricate with motor oil

WTF is going on?? Anybody have any tips? Lubricate? Don't lubricate? Twist the water pump on, or press it straight in?

Thanks

[B7S3wannabi]

So I got a b7 A4 not too long ago. Had oil filter housing leak, fixed that. Had a stuck thermostat, fixed that. I did not know the history on the car so I got a new water pump/timing belt from a local audi shop and replaced those. It seemed simple enough, until the water pump started leaking.

So I got a new o-ring (oriellys), pulled the water pump back off and super cleaned the water pump mating area. I got about 100 leak free miles and sure enough the stupid thing started leaking again.

Reading that autoparts store o-rings might not be as good as quality as oem; I just picked up a new o-ring from the dealer and I am going to pull this stupid thing apart for the third time in a month!

The first time I did not lubricate the oring, I read somewhere not to.
The second time I did lubricate with motor oil

WTF is going on?? Anybody have any tips? Lubricate? Don't lubricate? Twist the water pump on, or press it straight in?

Thanks

You're positive its the seal or could it be coming from the weep hole?

If it is for sure the seal, buy OEM. With the water pump removed use a fine grit (250ish) sand paper to clean the surface, use some sort of brake clean and wipe it down. Make certain there are no gouges in the block that could be damaging the seal when its being pushed in. I spray a little silicone onto the o-ring and push it straight in making sure it does not get pinched and goes evenly. Then screw the bolts in hand tight and begin torquing to the specified torque.... Edit (11ftlbs)

[Lasershark]

You're positive its the seal or could it be coming from the weep hole?

If it is for sure the seal, buy OEM. With the water pump removed use a fine grit (250ish) sand paper to clean the surface, use some sort of brake clean and wipe it down. Make certain there are no gouges in the block that could be damaging the seal when its being pushed in. I spray a little silicone onto the o-ring and push it straight in making sure it does not get pinched and goes evenly. Then screw the bolts in hand tight and begin torquing to the specified torque.... Edit (11ftlbs)

Not sure what weep hole you are talking about? (my first audi ever) The first time it leaked I could see (trace) the leak right up to the oring. Not sure on this second leak, but I know its the water pump area as the coolant is leaking from behind the timing belt cover in the same spot...

What is the spay silicone you are talking about?

[B7S3wannabi]

I apologize. I cannot confirm the B7 WP has a weep hole. Many water pumps have a small hole behind the pulley that when leaking means the shaft seals have failed.
Just make certain the leak is definitely from the gasket and not the pump.
For as inexpensive as they are and as much of a hassle it is to keep replacing, I would maybe purchase an OEM WP and seal and make this the final install.

There are a number of companies that make a silicone spray lubricant. Otherwise you can use some standard bearing grease.


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[wding2000]

I believe you should lube the o-ring with coolant, maybe silicon lubricant, but definitely not oil. For me, I can push in WP by hand, but it will not stay in (o-ring is very tight and pushes itself out). I had to wrench the three bolts, but do in in turn slowly, so they go in evenly so not to pinch o-ring.

[pezgoon]

Not sure what weep hole you are talking about? (my first audi ever) The first time it leaked I could see (trace) the leak right up to the oring. Not sure on this second leak, but I know its the water pump area as the coolant is leaking from behind the timing belt cover in the same spot...

What is the spay silicone you are talking about?

Just curious... is it possible for you to get a picture or where the coolant is leaking from behind the timing cover? I really really REALLY don’t want to pull my front clip off again but I’ve been slowly losing coolant since I did my timing belt last year and everywhere that is easily accessible I see nothing but when I replaced it there had been a leak from the same spot in the past (and possible from the weep hole I forget exactly) and also the thermostat. Thermostat isn’t leaking but idk about the WP

And regrettably PO put in the stop leak into the system to stop it instead of getting it fixed. Damned old people. I just do my best to forget that fact...


Also how much coolant do you lose?

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[mcpcartier]

When you put the new o-ring on did you see evidence it was where the leak was coming from?

I had thought my waterpump was leaking after doing the timing belt and turned out to be the cheap thermostat I replaced at the same time. I swapped that out for OEM and have been good since.

I wasted time getting a new water pump, pulling the front end off and finding no leak!!!

[a4lownslow]

Definitely verify whether it’s your waterpump or o-ring leaking.

Out of the dozen or so timing belt jobs I’ve done on-the b6/b7 I have never had an o-ring leak like you describe (you should always inspect the parts before you install anyways)

1: clean the sealing surface of the block thoroughly to remove any scaling or buildup. (I use a red scotch bright pad with a little brake clean)

2: Always use coolant to lubricate the o-ring

3: NEVER draw the waterpump into the block using the bolts. You want to use a gentle rocking back and forth motion until it seats flush with the block.

Good luck! I know it’s not something a person wants to do more than once, hopefully third times the charm



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[Lasershark]

Just curious... is it possible for you to get a picture or where the coolant is leaking from behind the timing cover? I really really REALLY don’t want to pull my front clip off again but I’ve been slowly losing coolant since I did my timing belt last year and everywhere that is easily accessible I see nothing but when I replaced it there had been a leak from the same spot in the past (and possible from the weep hole I forget exactly) and also the thermostat. Thermostat isn’t leaking but idk about the WP

And regrettably PO put in the stop leak into the system to stop it instead of getting it fixed. Damned old people. I just do my best to forget that fact...


Also how much coolant do you lose?

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I didn't get a pic, but if you run the car you should be able to see it leak out of the bottom of the lower timing cover. Day 1 that I noticed the leak it was probably only 10-20 ml a minute. Took the car home and let it sit and the next day when I looked, it was leaking probably around 200-300 ml a minute. Luckily I have other cars so I parked it...

[Lasershark]

Definitely verify whether it’s your waterpump or o-ring leaking.

Out of the dozen or so timing belt jobs I’ve done on-the b6/b7 I have never had an o-ring leak like you describe (you should always inspect the parts before you install anyways)

1: clean the sealing surface of the block thoroughly to remove any scaling or buildup. (I use a red scotch bright pad with a little brake clean)

2: Always use coolant to lubricate the o-ring

3: NEVER draw the waterpump into the block using the bolts. You want to use a gentle rocking back and forth motion until it seats flush with the block.

Good luck! I know it’s not something a person wants to do more than once, hopefully third times the charm


LASERSHARK SAYS:
Turns out it was in fact the water pump leaking and not the seal. I replaced the o-ring put timing belt and serp belt back on and fired it up and it instantly leaked. It looked like it was coming from the freeze plug on the wp. Threw in a new oem pump and ran the car for 30 minutes or so and no leaks. Pretty lame when a New pump leaks. It was a continental timing belt kit from a local audi shop, not sure what brand of pump comes with that kit but it said made in Germany...


I just used coolant to lube the seal and cleaned the mating surface with a fine grit sandpaper till it looked brand new. So 3rd/4th time was a charm, fingers crossed


P.S. still figuring out how this forum architecture works
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audi water pump bad.jpg

[a4lownslow]

audi water pump bad.jpg

Good to hear man. Doesn’t happen often where you get defective parts like that, but as you see it does happen. Especially sucks with a job like that!

Hey, on the bright side you can probably do the job in a couple hours now


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[Lasershark]

Good to hear man. Doesn’t happen often where you get defective parts like that, but as you see it does happen. Especially sucks with a job like that!

Hey, on the bright side you can probably do the job in a couple hours now


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Yep, getting quick at it. I can have the water pump out in just under an hour Although I would have preferred to only do it once

Thanks for everybody who posted!

[80sGuy]

The defective pump is probably made by Meyle, or equivalent lower end German-made auto part. Continental, known as 'ContiTech' are Italian-made, not German and they mostly manufactures plastic parts such as belts and tires...and they are good stuff! Can't believe an Audi dealer will sell anything below its OEM-branded equipment. Hope you didn't pay a (Audi) premium for that pump.

Correction:
Though some products such as tires and hoses are made in Germany under the 'Continental' label.

[Lasershark]

The defective pump is probably made by Meyle, or equivalent lower end German-made auto part. Continental, known as 'ContiTech' are Italian-made, not German and they mostly manufactures plastic parts such as belts and tires...and they are good stuff! Can't believe an Audi dealer will sell anything below its OEM-branded equipment. Hope you didn't pay a (Audi) premium for that pump.

Correction:
Though some products such as tires and hoses are made in Germany under the 'Continental' label.

Ok good to know about the belts and stuff. It wasn't the Audi dealership, it was a little repair shop that only fixes Audi's. I only have the weekends to work on my cars and that little Audi shop was the only one (besides the dealer) that had the timing/pump kit so I could fix my car sooner, it was cheaper than the dealership but more expensive than online.

I figured since it was an Audi only repair shop, that they would use quality stuff.

[audinutt]

Don't ever assume that I always buy my water pumps specifically from an Audi dealer

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[Lasershark]

oh believe me, lesson learned .