00 K2500 oil cooler line ( cooler side ) o-ring trouble

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JoePro

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Hello guys. I replaced the radiator in my 00 K2500 with a 5.7.
The engine oil cooler is located on drivers side of the radiator.

The existing engine oil cooler lines threaded into the radiator without the need to use the adapters provided.
My issue is the seal/ o-ring.
What was previously on the line was a thin flat rubber ring.
I replaced the rings with O-rings out of one of my kits and every time I tightened up the lines the o-ring was cut and damaged. I then picked attempted to use OEM O-rings from my parts supplier. Those also were cut and damaged during install. I ended up using some that I had in another kit, tightened the lines and put it back together. I attempted install with at least 4 different o-ring sizes, lubricated with grease and dry.
I am not satisfied with this job.

Has anyone else found a better seal or o-ring?
 

454cid

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When I needed new o-rings I went to the dealer, and had no problems. O-rings from the kits that all the local parts stores have behind the counter were too fat. Unfortunately, I think the o-rings I bought are NLA from the dealer.

The thin flat rubber ring, was probably an o-ring. They deform after awhile from the pressure and heat.
 

Schurkey

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The existing engine oil cooler lines threaded into the radiator without the need to use the adapters provided.
My issue is the seal/ o-ring.
First Guess: Incorrect sealing surface in the radiator ports. Which might be what the "adapters" are supposed to correct.

IN-FOCUS, properly-cropped photos would be helpful. I'd want to see the inside of the original radiator where the tubes seated, the inside of the new rad where the tubes are seated, and the inside of the "adapters" where the tubes are supposed to seat.
 

PlayingWithTBI

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When I needed new o-rings I went to the dealer, and had no problems. O-rings from the kits that all the local parts stores have behind the counter were too fat. Unfortunately, I think the o-rings I bought are NLA from the dealer.

You can go to an industrial/hydraulic supply store, they usually have all different durometer (hardness) and material (Buna-N, PTFE (Teflon), Viton, etc), and thicknesses. On some high pressure applications we used a "backer", which is generally a flat Teflon or metal washer, to keep the O-ring from deforming.
 
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hatzie

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GM is still using the Jiffy-Tite® fittings today for oil and transmisson cooler lines. They're real common. I just installed a Long Tru Cool LPD transmission cooler with GM fittings and home made custom Ni-Copp lines that I flared to match with my Mastercool and beaded for the SAE J1910 hose on the other end.
I agree on hitting up the counter guy at a hydraulic supply store.
Worst case get the whole female fitting from Delco. The ones for my Long were around $8 from Delco.

An interesting Article on these fittings. https://icemancooling.com/2011/01/28/oil-cooler-connections-gm-quick-connects/
 

454cid

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GM is still using the Jiffy-Tite® fittings today for oil and transmisson cooler lines.

Wrong side of the line... that's the engine side. The radiator/oil-cooler side just needs o-rings. It's not a quick connect of any kind... at least not on my 99.

Edit: Here's a good picture.

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I had never heard of a Jiffy-Tite connector before. I thought those were a GM creation. I just noticed that the desctpition from AC Delco does call the other side a Jiffy-Tite flare. Sunsong just calls it a quick-connect.
 
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JoePro

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Yes that is the end I am working with.
I have 100's of o-rings here.
I work on farm equipment for my day job an farm and work in the shop at home for my 2nd and third job.

Most people likely wouldn't loosen the line to check the o ring after they tightened the line the first time but I'm very picky and particular.
The fitting in the radiator isn't replaceable and the lines do not thread into the adapters provided they do thread directly into the cooler.
I'm baffled and maybe ill just have to live with it if it doesn't leak but I'm not satisfied.
I can't believe that far as many of these aftermarket radiators as they sell, there isn't a better seal, or a better way to seal it.
 

hatzie

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Wrong side of the line... that's the engine side. The radiator/oil-cooler side just needs o-rings. It's not a quick connect of any kind... at least not on my 99.

Edit: Here's a good picture.

You must be registered for see images attach


I had never heard of a Jiffy-Tite connector before. I thought those were a GM creation. I just noticed that the description from AC Delco does call the other side a Jiffy-Tite flare. Sunsong just calls it a quick-connect.

Apparently GM did not come up with that particular abomination.
Depends on the model year what they used.
My 2000 GMC Sierra C2500 has Jiffy-Tite on the block and threaded in the external oil cooler... The NV4500 doesn't have a cooler.
My 2005 2500HD and 2009 Impala SS have Jiffy-Tite fittings on the transmission and oil cooler lines at the radiator and the AUX coolers.
 
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