I'm going to try liquid copper first on a suggestion from someone who used it on his truck. Right now, it's hardly leaking. Only drips slowly when the car is running. The new rubber O-ring on the tube didn't get in straight. I can see a little of it poking througn on the edge. If that doesn't work, I'll have to drian the system anyway. I will have to pull it apart again. I'll try the tube first. My 84 had some play in the tube when I did that one a few years ago. This one won't move. I may have to bend it. The pump sealed so well I'm afraid it will leak if I pull it off and reinstall it + it's a pain to remove.
I'll let everyone know if "Liquid Copper" works or cruds up the system.
Ben

I doubt any product will stop this leak. The leak is from a misplaced rubber seal on the pipe end... it's not like a crack in a metal radiator.

It's just going to keep leaking. I don't like what most stop-leak products do to the cooling system. Mainly I think they gum up radiator passages and thermostats.

The best thing to do, and I just did it, is to buy the water pump seal kit ($3) and drain the system and try again.

One tip I offer people doing this: apply grease to the pipe o-ring and the top seal, so they slip right into place. This keeps them from getting rolled over or pushed to the side. I use silicone brake grease but lots of other things work. I've seen pro mechanics use Lithium grease too.

I use a pry bar against the alternator top to push the water pump up into place securely- it's a tight fit to get the other bolts in for certain. And I scrape the waterpump body and block sealing surfaces clean of old paper gasket material using a razor.

Good luck!
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Rob Bareiss, New London CT ::: '87 244DL/M47- 229K, 88 744GLE- 218K, 82 245T-181K Also responsible for the care and feeding of: 88 745GLE, 231K, 87 244DL, 239K, 88 245DL, 246K

Why not free up the pipe so you can get the seal in right?

There are only 2 bolts holding it tight—the one at the pump and one back under the #4 exhaust runner (not easy, but doable).

With those 2 bolts out, the hose at the back end should flex enough to let you move the pipe back and get the seal squared away.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

I'm interested in this "Liquid Copper". Can you get it any large parts store?

My upper (mushroom?) waterpump seal has had a very slow leak for awhile. Other than that the pump is fine so I've been "milking it" to see if it will last until it is time for my next timing belt change.

I've been reluctant to use Barr's or similar because of the possibility of gunking up the heater core or something else. Maybe this is better???


Thanks,

Jim 90 244DL 234K