I replaced my WP/TB a little over a year ago. It was a rebuilt water pump, now has 15Kmiles on it. It's leaking bad. I'm getting ready to tear down and replace with Greg Schickel's help. Haven't made the decision to replace with another rebuilt, or go the extra for a new one. Any input on rebuilt vs. new? Did I just get a bum unit? Thanks

 

The 928 Intl rebuilt on my car has no leaks, no problems. More will chime in, I'm sure.

That said, if you are uncomfortable with the idea of rework for a leaking pump, decide if the extra cost is worth the comfort. I probably could have left the original (65k miles on the pump) installed and been just fine, but there's that nagging fear that the old one will give up the ghost somewhere at the far end of a trip a long ways from home. Since this one seems fine, it will likely stay in through the next TB replacement adventure. But that's not an option for you yet...

Are you sure it's the pump shaft that's leaking on yours?

 

I finally got a good one after a few tries. Now, the latest new non rebuilt seems to be working well.

 

Mine is rebuilt from from 928 Specialist and it is bone dry.

Maybe yours was a poor rebuild or wasn't sealed to the block well.

 

dr Bob, not sure if it is the pump shaft, but lots of coolant from the cover. Greg and I start tearing it down in about an hour.

 

Check the pivot/shoulder bolt on the tensioner. That screws into the WP and can leak if not sealed up or (the horror) it's backing out.

I've always had good luck with rebuilts, btw.(928 Int'l)

 

Some of the bolts on the WP, including the tensioner arm pivot on the pre-S4 pumps I guess, need a bit of thread sealer where they enter the coolant jacket to prevent leakage. The shaft seal has a relief port in the casting forward of the seal but behind the bearing, so if that shaft seal is leaking it's pretty easy to see. You can get the covers off, hook up the radiator hoses again, and use a system pressure tester to see where the coolant is escaping.

FWIW, I did mine and it seemed to be fine except for some annoying seepage. Guidance from 928 Int'l led me to seal up a couple bolts with thread sealant paste, primarily the tensioner housing bolts. Then I figured out that the radiator hose clamps weren't snug enough on the new hoses, and that finally made the car totally leak free. I was convinced that my workmanship was stellar and the leak was from a defective rebuild, but was pleasantly surprised to find that I could fix the leaks with an hour of work rather than another 8 hour session with the tools and the back brace. Great guidance from Mark and Jim, who had instantly offered to give me another pump to take with me just in case. CS like that is what allows me to own the car.

 

Thanks fella's....
You were spot-on,.... Just got it apart, and it's leaking out from the tensioner arm pivot bolt.....
Apparently on pre S-4's this bolt "does" go into the water pump jacket....
(Never seen this on S-4 and later...)
(We didn't drain the block, which made this easier to find....)

Leave it to the dealer who installed this belt and pump, to not know to put sealer on this bolt....
They also left this same tensioner pivot bolt very loose......
It was backed out 1/4 inch......
The other issue is that the belt is tracking poorly over the bottom tensioner roller, and the tensioner rod is angled towards the back..... I think this will clear up on its own after we replace the antifreeze-soaked belt and re-adjust the tensioner and get this bolt put back in tight.....

Here's a pic,...... If anyone has seen this before, feel free to chime-in......

Thanks,
Greg and Robert

 

Lots of issues there.

The water pump pulley looks old? The low tension guide pulley under the crank is caked in grime. Is the low tension sensor working?

It was fortunate in a way that they didn't put sealer on the shoulder bolt, otherwise this might have ended badly in short order.

Time to talk to Roger about an upgrade.

 

Is that the correct pivot bolt? Quite different from my S4.

As Ken said there's multiple issues in your pic; is the pivot arm bent?

 

Also do not like the sound of that, Time for a new bolt?

Did you say it was a pre-S4? So no tensioner warning sensor?

Marton

 

it looks like your tensioner arm isnt in plane with the belt run, this will cause the belt to run into the rear side of the crank dampner and will in short order make whiskers of any belt, SO the pivot bolt is either loose in the waterpump (as previously stated) OR the pivot to tensioner bolt has play or clearance in the pivot bolt hole OR you need new plastic bushings in the pivot bolt hole. I suggest that you make this part of the belt tension system perfect otherwise you will be doing this job all over. Also consider to clean/replace the lower belt guide bearing under the crank. I am having the problem with my 84 Euro, i will find a fix

 

That pivot bolt is correct, as has been said, the early 32V ones are different from the S4 and later. The bolt threads into the waterpump and needs to be sealed. This was not a good thing for me to be correct on, but it is a good thing you caught it when you did. This could have been disastrous.

 

I've ordered a copper bridge for the sensor, mine was broken in half, plus it didn't have a wire connected to it. I think we found the correct wire, broken, but sticking out about where the top of the cover would be if on. It looks like the tensioner arm is ok, it was cocked side ways because of the loose shaft bolt. I've ordered new bearing sleeve for the arm, which was worn, plus a new Tensioner arm shaft bolt. It looks like I was pretty lucky that I didn't end up with major damage. I drove it to SITM knowing I had a small coolant leak, I just carried extra coolant for the trip. A couple days ago while at Greg's house it started pouring out, so he gave me a ride home and I left the shark in his garage to start the teardown the next day. Can some one tell me what sealant to use on the shaft bolt to seal it and keep it from backing out again?

 

Loc-tite should do the trick for both duties on the pivot bolt threads. For bolts that you want to be able to get out later, you can use the plumbers thread sealing paste that comes in a small tube. Just a small wipe across the threads in one or two lines will do the trick. The liquid follows thr hollow space on the back of the thread. There's really just one thread around and around the bolt, so just enough to seal it in a few places and you'll be good to go. Too much will lubricate the threads, but that's not normally a problem in this service.