Coolant leak from an unknown source
Thread Starter
Heel & Toe
Joined: Jul 2014
Posts: 17
Likes: 0
From: Palestine Texas
Coolant leak from an unknown source
I have an early 1977 L-48 C3. No mods of any kind. Original engine. 65K miles with no abuse. I replaced the water pump due to the tell-tale chirp/squeal from the water pump bearing. I verified that there are no coolant leaks from the new water pump. I also verified that there were no coolant leaks from the new thermostat or thermostat housing or gasket. The lower radiator hose is not leaking, and there is no leak from the rear plate from the new water pump. There IS a leak from around the bottom of the timing chain cover. At least that is where it drips from. I checked the intake manifold and there is no indications of it leaking there. When I use my trusty mirror and flashlight, it looks like a steady drip coming from near the timing chain cover. I pulled the engine oil dipstick and there are no indications that there is coolant mixed with the engine oil. Also, now the crankshaft pulley is hitting the water pump pulley. It did not do that previously. Could a crankshaft bearing have shattered, spun, came apart? Cracked block? The engine still runs great. No awkward noises except for the pulleys clanging into each other. Your thoughts, please? Thank you!
Thread Starter
Heel & Toe
Joined: Jul 2014
Posts: 17
Likes: 0
From: Palestine Texas
To add to this, the coolant level in the radiator still seems to hold steady (for the most part, of course). It only leaks from the previously described area, while the engine is running or immediately after you shut off the engine.
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
Since you just changed the water pump and thats when both problems started, I'd suspect the water pump is the source of both problems. The shaft might be bent causing the pulley contact and the leak. Don't worry about a cracked block or spun bearings.
Thread Starter
Heel & Toe
Joined: Jul 2014
Posts: 17
Likes: 0
From: Palestine Texas
I got the pump at the local O'Reilly's. I thought that might be my first mistake. I just ordered minutes ago, a new water pump from Eckler's for my car. Along with new bolts, nipple, studs (for fan clutch), etc. Did I just make my 2nd mistake?
Melting Slicks
Joined: Oct 2006
Posts: 2,417
Likes: 336
From: Texas
hopefully not, it should fit and have the 3/4 hub shaft. im running a water pump i got from rockauto. years ago , perfect oem replacement..... the one i had looked at perviously at Oriellys didnt look right and the shaft was 5/8, thats why i ordered from r.a.
Thread Starter
Heel & Toe
Joined: Jul 2014
Posts: 17
Likes: 0
From: Palestine Texas
Thanks for the input! Since this is my toy and not a daily driver, I will gladly wait on parts. Well, that and hopefully for some cooler weather! August in Texas is unforgiving, though.
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Advanced
Joined: Apr 2006
Posts: 75
Likes: 0
From: Ridge NY
I had a leak from an unknown source on my 76 L48. Turned out to be an old jb weld repair that finally gave up. Didn't see it at first because it was a nice looking patch painted chevy orange. Not looking to put the jinx on you, just my experience. Good excuse to put in a new crate engine...
Thread Starter
Heel & Toe
Joined: Jul 2014
Posts: 17
Likes: 0
From: Palestine Texas
Ok. The verdict is in. The water pump WAS leaking at the block from the passenger side front where it bolts up. The metal dowel was not in place when I took the old one off and neither of the new pumps (X2) came with it. Contributing factor as far as the alignment of the pump goes. Now, on to the clanging pulleys. The thermal fan clutch shaft was bent slightly. I did not check it when I received it and I don't know if it came that way or something happened to make it that way. It could have possibly bent the water pump shaft too. I can't see it with my naked eye. And I didn't put a dial on it. So, now we know. ASSUME NOTHING!! And don't overlook the obvious, right? So, it will be a new water pump AND a new fan clutch when I put it back together. Seems to be a HUGE relief since I was beginning to worry about a cracked block! (Big sigh of relief!!)