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Coolant elbow installation
Posted: Tue Aug 28, 2018 3:12 pm
by BonneRebel
Ok, so Bonnie's coolant elbows have cracked and need replacing. I've removed the upper one without removing the alternator and tensioner and all that crap. Question os, can I just pop the new ones in without all the work?? (Excuse me for being lazy)

Re: Coolant elbow installation
Posted: Tue Aug 28, 2018 3:25 pm
by harofreak00
Please explain how you changed the upper elbow without unbolting the tensioner.

Re: Coolant elbow installation
Posted: Tue Aug 28, 2018 3:42 pm
by Boosted52405
Sorry, no I don't think you can. I just finished this job a few days ago and they go in together at the same time. Be sure to put a little RTV on there to help it seal (or so I read, I haven't started mine up yet!).
EDIT - and of course go with the aluminum ones. I was surprised to see that the ACDelco ones from RockAuto are now aluminum (Dorman ones also at your local parts store i'm sure).
Re: Coolant elbow installation
Posted: Tue Aug 28, 2018 4:26 pm
by RJolly87
It just said that he removed it, which probably means it came out in pieces.
Which means he will probably need to unbolt a bunch of things to put new ones in, unless he wants to try putting it in in pieces.
Re: Coolant elbow installation
Posted: Tue Aug 28, 2018 7:44 pm
by luke_dubs
Yeah. You gotta take the alternator and tensioner off - among other things. Make sure nothing is stuck where the elbows normally go (old elbows were this way for me). Lastly, I was told by my highly trusted shop that the aluminum elbows can go bad faster than the regular rubber ones. Something to keep in mind. OH. Another thing. Make sure you keep the unplugged alternator cable away from the fuel injectors.
Re: Coolant elbow installation
Posted: Tue Aug 28, 2018 7:49 pm
by dougtoth
I believe the aluminum elbows are better than the plastic elbows.
The problem I had is with the garbage O-rings that come on the elbows.(material broke down)
I still use the aluminum ones but I go with the OEM O-rings.
Have not had a problem since.
Re: Coolant elbow installation
Posted: Tue Aug 28, 2018 10:43 pm
by BonneRebel
Thanks for all the tips guys, and yeah it broke off pieces

I ordered the Doorman aluminum from Amazon, I shall start tomorrow when they arrive, are the o rings really that bad?
Re: Coolant elbow installation
Posted: Wed Aug 29, 2018 8:50 am
by peter
Personally, I've done this job about 5 times on various 3800s and never have used RTV on the coolant elbows. With that said I've always used AC Delco/GM part coolant elbows
I just clean up the bore with a scuff pad; use Vaseline on the o-ring during installation so it installs smoothly and it's always been fine.
Re: Coolant elbow installation
Posted: Wed Aug 29, 2018 9:44 am
by dougtoth
I use the Dorman aluminum elbows (47065HP) with the GM OEM O-rings.
Part number for the smaller one is 25537068.
You need (3) for the two elbows.
Part number 24502846 is the larger one.
You need (1) for the two elbows.
Make sure the holes are cleaned out and no broken pieces are in there.
Then use Vaseline on all the O-rings.
No RTV is needed.
Re: Coolant elbow installation
Posted: Wed Aug 29, 2018 11:34 am
by Boosted52405
Sorry for the bad info on the RTV, I guess keep it in mind if it leaks at all. I have read quite a bit about them leaking and needing RTV, but many threads were from years back perhaps the parts are improved. Some have said it's the only o-ring ever they've used RTV on. There are ACDelco aluminum ones are RockAuto - I haven't heard of anyone using them but I assume they have the better o-rings referenced. Part numbers 19310306 and 19310305.
Re: Coolant elbow installation
Posted: Wed Aug 29, 2018 12:13 pm
by peter
The RTV aspect is a common personal preference thing for anything automotive. My typical take is:
Paper gasket: yes to RTV
Rubber gasket: no to RTV
I find Rubber and RTV together tend to cause leaks rather than prevent but I'm sure someone will disagree
Re: Coolant elbow installation
Posted: Wed Aug 29, 2018 7:26 pm
by BonneRebel

Well guys, I changed both out today.. took about 45 minutes. I applied some water pump and thermostat rtv and let it dry for two hours, I gave the hose a squeeze and NO MORE LEAKS!!. I just came in from a 10-15 minute drive after burping the system, made a stop at the g station left her running, came out.. saw no leaks, no more overheating. I'll take her on the highway tomorrow and give her a push. Once again thanks for all the help! (Onto the next project) the oil pan gasket
