Generally accepted point of failure is the plastic elbow that connects the thermostat to the water pump. Thought the brass replacement might be the solution but 20,000 miles after changing out the elbow with the kit from RKX which includes a new O ring seal and plastic keeper/release I now have two motors with pretty good leaks at the brass elbow where it goes into the water pump. I know people who tried the aftermarket complete metal pipe kit have had problems with the aftermarket O ring seals. I'm thinking this little seal might be a similarly weak link. I have a couple new kits coming via Amazon but wondering if I can match up the O ring seal with something more durable. I don't think the factory seal is available without an entire water pump attached?

 

You can't just buy a new elbow with the included O-ring and plastic collar?

I just checked my new-in-box OEM water pump and it does NOT include the O-ring, just the plastic collar already inserted.

 

That’s the kit I’ve been buying. The brass elbow is obviously more robust than the factory plastic one but it seems the supplied O ring is not as robust as the factory O ring. Wanted to know if ya’ll had similar experience and found a solution. The aftermarket O ring kits are not helpful, the O’s aren’t as thick.

 

It looks like the hose (C2Z28258) does not come with the O-ring.

I think you will have to go to the dealer parts department for this O-ring if you want OEM.

Would a dab of Hylomar Blue or other liquid gasket product around the O-ring and reinstall do the trick?

 

@GerbilEngineer just did this work - another idea - could 2 O-rings be stacked on to tighten the fit?

 

I would take the o-ring out and measure it, then order something higher quality via mcmaster or somewhere. I was looking into that for the I6 turbo coolant lines before they launched the updated parts. We had dozens of customer cars down at the store with no parts, and I could have ordered a more robust o-ring for $15/100.

 

New O ring from replacement kits I ordered miked out at 10mm OD, 5.5MM ID and 2.25MM thick. Found an O ring on McMaster that matched and ordered the most heat resilient version. I’ll try them out this weekend.

 

It's a bit hard to tell from the photo but it looks like the brass elbow is a right angle while the plastic one is greater than 90 deg ?
Just wondering if that is the case the O ring may not be completely sealing on the spiggot as it's on an angle to the water pump receptacle ??

 

The photo is deceiving, The angle of the brass elbow is the same as the plastic one.
In both of my effected motors, the brass elbow is not fitting as tight as it did when first installed.
We tried an O ring from an assortment kit my tech had but the fit was way too loose.

 

I broke the plastic elbow when doing my water pipes upgrade, bought a brass version but did not like the way it fit (too loose indeed).
In the end I went full OEM and bought the WP to get a new o-ring and female bit, and a thermostat pipe to get the OEM elbow.

Another option is to get the brass version and use coolant-rated sealant. Probably a surefire to do this but you'll need to drain a lot of your coolant to get the mating surface dry.