How to - Install -AN oil cooler lines

Sub'ed for this awesome info for these damn leaky oil cooler lines. This set that is now leaking is my 4th set so far.

Finally completed this upgrade. What a PITA if you do not remove the oil filter adapter. I was in a hurry and only removed the stock lines. Little did I think that by the time a wrench was put on the fittings this left about 8° to turn the wrench to tighten everything. Lastly the drive line for the 4wd was in the way. Here are a few photos of the fittings and line build.

I vote for this to be a sticky. And I'd love to see this for the power steering lines as well too.

Sent from a flagged XT1254
Tyler/T-Unit

I also have gone through several sets of oil cooler lines. Will definitely be looking into getting this together. Power steering lines would be awesome to. I'm about to replace them again there.

Found another 20mm x 1.5 to -6AN adapter from Vibrant Performance if anyone's looking. Part number 16620.

https://www.summitracing.com/parts/vpe-16620

VCaddy said:

-6 male to 20mm x 1.5 adapters for the radiator fittings. These are pretty tough to find, ANPlumbing is the only place I saw them.

Click to expand...

I have the radiator out of my '97 K2500 7.4L as I'm typing this. The oil cooler plumbing has--and is--giving me problems. It may be that my 3-model-year newer, big-block vehicle is different than yours.

Three things.

1. I would be scared to death to run -6 hose in this application. -6 is the equivalent to 3/8 tubing. My OEM hoses are 1/2" tubing or the metric equivalent on the metal sections. I suggest -8 hose, -10 might be better.

2. I haven't looked up the fittings you suggest, but another poster provided this photo:

and

df2x4 said:

Found another 20mm x 1.5 to -6AN adapter from Vibrant Performance if anyone's looking. Part number 16620.

https://www.summitracing.com/parts/vpe-16620

Click to expand...

On MY truck, these radiator fittings would be all wrong. The oil cooler hoses are intended to thread into the radiator oil cooler and seal using an O-ring. No O-ring, no proper seal. I expect someone makes the proper O-ring-to-37 degree flare fittings. I've got some for similar-but-smaller hose sizes for power steering and for TBI fuel systems.

Did the fittings you use look like this? Straight, Metric threads, O-ring seal just like the original hose. This photo is for a smaller fitting--16mm X 1.5 X -6. But the concept is the same. I'd want--I guess--20mm X 1.5 X -8 or -10.

VCaddy said:

Here is how the hoses are routed, just like factory. The little clamp that the factory lines use works great, doesn't pinch the AN hose at all.

You must be registered for see images attach

Click to expand...

3. I think I'm seeing the pair of steel-braided hoses tied together with tyraps or metal clips, so the steel braid from each hose is touching the other hose. This should be corrected. Steel braid covering the hose will act like a dull hack-saw on anything it rubs against, including other hoses. The hoses must be secured, but separated from each other, and moved away from the radiator shroud, Power Steering tube, or any other unintended contact. Most folks use cushion clamps of the appropriate inside diameter. The cushion clamps might also be secured to a sheetmetal bracket, or running the screws into vehicle structure to prevent abrasion with other parts.

If it's any consolation, the oil that doesn't hit the cooler does go through the motor, so at worst he's just not getting the most from the cooler/warmer.

Schurkey said:

On MY truck, these radiator fittings would be all wrong. The oil cooler hoses are intended to thread into the radiator oil cooler and seal using an O-ring. No O-ring, no proper seal. I expect someone makes the proper O-ring-to-37 degree flare fittings. I've got some for similar-but-smaller hose sizes for power steering and for TBI fuel systems.

Did the fittings you use look like this? Straight, Metric threads, O-ring seal just like the original hose. This photo is for a smaller fitting--16mm X 1.5 X -6. But the concept is the same. I'd want--I guess--20mm X 1.5 X -8 or -10.

Click to expand...

If anyone knows where to find a male metric o-ring to AN adapter like this in 20mm x 1.5 I'd love to see a part number. I've been Googling for 20min or so and all I can find are those smaller KRC 16 x 1.5s in the photo.

My apologies if that Vibrant part I linked is incorrect, I've never had the oil cooler fittings apart on my trucks so I wasn't sure what they looked like.

For all I know, the earlier, or the small-block applications are different from what I'm dealing with.

(I can't get the ******' lower oil cooler hose to un-screw from the radiator. Seized solid. Upper hose on the rad came out nicely.)

I think it's the earlier trucks that use the quick connect on the radiator side.