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Cast coolant elbow O ring. Other options

chevyy1212

chevyy1212

New member
I took the big one off the extra coolant elbow and put it on the cast one. Went on wayyy to easy. Of course still leakin same spot. Any other options you guys have found in the O ring world that seals a little tighter.
 


Larger o-ring or RTV are the only options besides getting a new elbow. Personally I would spend the $5 on the new elbow(s).
 
He has a 98 which has an elbow cast into the timing cover he can't replace it without replacing the whole cover.
 
i just did this my self not to long ago. also a 98 GS. i used the O ring off the extra elbow, i also cleaned the crap out of the hole. lubed with a dab of oil and it slid right in, no leaks.
 


My 99 has this problem.. It could go for two months and never drip a drop of water, then I could go through a gallon every week.. Frustrating as hell.. I have been through 3 sets of elbows in the past year. I have a set from a local GM dealer now that I am going to change them out while I have the motor apart due to engine fire.. I'm going to use the oil idea and lube up the holes some so the rings may seat better AND I'm going to use some black RTV.

One question I have about the RTV is should you just put a bead around the o-ring then push it in, or once you get the alternator bracket back bolted down should you squeeze the RTV around the gap then?
 
I put a thin layer of copper RTV in the groove where the O ring goes to raise out the ring a little. Seem to be good now. If not then I'll RTV evvvverrrryyyything and the O ring itself its a super easy job so im not to worried just annoyed. Yes 98 has the cast elbow it's a love hate thing.
 
What keeps these from sealing is that people don't clean the hole where the o-ring seats.

I use 400 grit sand paper...put it back together (new elbows) with a coating of plumbers silicone sealant and hadn't leaked for over 50K.

The aluminum corrodes right where the o-ring is supposed to seat. It's a white powdery mess. Clean it up and it will seal.

As far as the RTV goes: put a light coating on the inside of the hole and a coating on and around the o-ring and put it together. Many people have had good luck with the RTV.
 


I use fine steel wool. It's all good either way. However if you still have a leak, then you should look at the timing cover closely. The reason GM changed to both being plastic is the timing cover breaks easily when you pull/push on the tensioner the wrong way during disassembly.
 
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