How to change coolant elbows

**BillBoost37** · 07-26-2011

Tools required:
Rachet
8mm wrench
10mm deep socket
13mm deep socket
15mm shallow socket
15mm Deep socket
Piece of steel wool
Small amount of lubricant (oil/vasoline/grease)
Catch basin for coolant

Dorman 47065/Napa 660-1736/GM Dealer (Coolant Elbows)

This is written for a 99+ W body or 00+ C/H/G body, if your car is a Series II motor and before these years, please see the note at bottom of writeup.

Unhook the negative terminal of the battery 8mm
Untension the accessory belt shallow 15mm
Move the coolant overflow and lay it on the front of the motor.
Remove the alternator from the tensioner bracket 13mm/15mm
Remove three bolts holding the tensioner bracket to the cylinder head (see picture)

Wiggle the bracket and it will come off. (See note if you have an earlier year, this is important)
Remove any pieces of elbow stuck in the LIM, timing cover or the tensioner bracket.
Use the steel wool to clean the old elbow's ridge out of those areas.
Lubricate all o-rings on the new elbows
Install the elbow with equal sized ends in the top hole of the tensioner and the other into the bottom hole.
Line up the elbows and wiggle the tensioner into place
Start all three bolts to hold the tensioner to the head
Tighten the bolts a little at a time and gently wiggle the upper elbow as you do this until the bolts are tight and the upper elbow still wiggle slightly.
Reinstall the alternator
Reinstall the belt
Reinstall coolant overflow
Hook up battery
Fill with coolant and bleed system.

Note: If your car is 96-99 for the bodies listed in the important note, then your alternator bracket has a metal lower coolant elbow cast as part of the assembly. This is important because you can break the timing cover if you pull it from driver side to passenger side. To remove the alt bracket you want to wiggle it front to back in the engine bay only. This will feel like it takes forever. Do not give up and if your upper coolant elbow (plastic) breaks, that is fine. Wiggle and remove as gently as possible. This will keep you from breaking a timing cover.

Easy

**grandamle91** · 01-26-2012

What can I do if my motor keeps blowing them out?

**NegativeOne13** · 01-26-2012

What do you mean blowing them out? They are plastic and crack/break after time.

**grandamle91** · 01-27-2012

Every new set I put in the pop out after couple 100 miles

**BillBoost37** · 01-27-2012

When you say it pops out.. your cooling system should have ~16psi of pressure based on the cap. The tensioner should hold the elbow from popping out of the lim and the lim holds it from popping out of the tensioner.

I'd check for an overpressurized issue.

**grandamle91** · 01-27-2012

I had it tested and at idle its around 15psi and when i rev it to 4k its jumps to 30psi. So cap must be bad?

**gtpeddie** · 05-29-2012

i just blew one out today during WOT i replaced the last one a while back maybe 5 months ago or so but mine snapped it didn't pop out do you think ill be okay with the new one? and how can i do a pressure test? and if i put a new cap on would the pressure be normal? i also blew out a rear heater hose back in September or November but they looked like they needed to be replaced any way

i have a 97 GTP i just replaced the coolant elbow today

**gmpowered** · 05-29-2012

Originally Posted by grandamle91

I had it tested and at idle its around 15psi and when i rev it to 4k its jumps to 30psi. So cap must be bad?

More than likely

Good write up Bill!!

**eric37428** · 05-31-2012

i cant get the belt off. i loosened the nut holding the idler pully but the belt wont budge.

**BillBoost37** · 05-31-2012

The nut on the alternator bracket/tensioner when pushed counter clockwise should move the pulley and release tension.

**bps02gtp** · 05-31-2012

in other words tighten it back up and keep tightening till the pulley starts to move lol

**BillBoost37** · 06-01-2012

Originally Posted by bps02gtp

in other words tighten it back up and keep tightening till the pulley starts to move lol

Not necessarily.

I said counter clockwise, which most would consider loosening. However being a tensioner it has a reverse threaded bolt, therefore by telling him the direction....I tried to take the possible confusion out of the equation.

**bps02gtp** · 06-01-2012

in order to move the pulley you have to go the same direction as tightening dont you? doesnt matter if its counter clock or regular clock? thats y i told him to just tighten because thats easier to figure out then knowing if its reversed thread or not.

**chevyy1212** · 06-18-2012

Ok kind of old topic but I have a 98 and the cast elbow seems to not be sealing up just right. The O ring from the plastic elbow I don't use was I supposed to? Any little tricks I just used the same O ring since it wasn't old and slid it on. I know you got a tip for me Billy

**BillBoost37** · 06-19-2012

It's not an old thread..it's a How to ...lol

Yes, use the big o-ring off the elbow you didn't use. That's the correct ring for your metal elbow.

**chevyy1212** · 06-19-2012

Originally Posted by BillBoost37

It's not an old thread..it's a How to ...lol

Yes, use the big o-ring off the elbow you didn't use. That's the correct ring for your metal elbow.

Damn that's what I thought. I just reused what was on there even tho I knew deep deep down it was that O ring I even took it off. Oh well I'll just keep an eye on it. I'm not 100% it's leaking from there since there's well no more leak just may be coolant left over from taking it apart in the first place. Now I know tho

**40th GP** · 09-06-2012

So I changed my elbows when I did the LIM about 2 years ago. I went with the Dorman replacements, but when I had it all back together coolant would seep out around the upper elbow (nothing major, but just enough to smell the burning coolant on the engine and see a little wetness, and have to add a touch of coolant every other week or so). I am kind of anal and that was not going to work for me, so I went ahead and paid about 5 times more and bough new elbows from the dealer. Put them in and same thing is happening---slight seepage from the upper elbow. Might be worth noting that the original elbows were not leaking, just changed them as a precaution while I was doing the LIM. I also managed to get them out without breaking them, but they are hard and brittle and figured new was the way to go.

Have I installed it wrong? I can't imagine 2 different sets of new ones being bad. I can push in on the upper elbow and feel it go in just ever so slightly. I am thinking that it is just not seated all the way into the manifold, but the tensioner bracket piece they mount in is tight. Might also be worth noting that when I had the LIM off I had it blasted and steamed at an engine shop, so it looks like brand new and there was no old crap in there that could be causing a leak.

Any ideas??? It is driving me nuts and I am going to tear back into it this weekend because my power steering has sprung a leak. Thinking I might replace the water pump while in there as well just so when it is all buttoned back up everything will be done, but I need some ideas on this crazy elbow seeping issue...

**BillBoost37** · 09-06-2012

Take steel wool and clean the holes where the elbows are located. Likely there's a ring of crud built up that's causing you to leak. Also check out Rockauto part number 47065HP, aluminum are available now.

**40th GP** · 09-06-2012

Originally Posted by BillBoost37

Take steel wool and clean the holes where the elbows are located. Likely there's a ring of crud built up that's causing you to leak. Also check out Rockauto part number 47065HP, aluminum are available now.

Nice, those look sweet and you get both for less than I paid for one at the dealer. However I would be concerned that I would put those in and have the same problem again. When I did the LIM I had the manifold blasted and steamed at an engine shop and it was basically brand new when I put it back together. I can try the steel wool and clean the holes again, but I highly doubt there was anything in there that could be causing a problem since it was clean as can be when it went together and they leaked from the get-go. Any other ideas?

**BillBoost37** · 09-06-2012

Yes.. magic.

If the bore of those holes are clean, and have no cracks or flash from the casting etc... then it would have to be an issue with the elbow or the install. Since you changed it again...and these are a very simple install. It's tough to have a different idea about what it could be.