DIY Oil Cooler Line Replacement

[Mshawn]

On 3/16/2022 at 5:34 PM, DeePa said:

Has anyone figured out aftermarket lines? I’ve done the GM ones twice already. 
 

I’d love to do braided lines end to end. 

Any good hydraulic hose builder in your city or town, ask them if they build a/c lines. They can build them with a better quality, and parts. Ask them if the build them in house. That’s the shop you want. Mac tools sales a good hand crimper for ac lines which you can use the crimp oil cooler/transmission cooler. you would have to find a fittings supplier( good google search should provide a good supplier. Gates, Eaton, and Parker all build these fitting for the ends of the lines and the line its self. It may not look perfectly like the factory line but it will work better and not leak. Most of the problems with the oil cooler lines from GM is they are cheap Chinese and are not at the proper crimp specs. When mine leak I will not spend time with the dealership. Warranty or not, I will order in the hose and the fitting and crimp them in my shop. Gates makes a very tough hose for this and will more than likely last the life of my truck. I hope some of this helps

Edited November 17, 2023 by Mshawn

[Frank4202]

I'm in the same situation right now. I can see the seepage starting. Dealer quoted $160 for the lines and 2.4 hours of labour to install so $615 taxes in (Price in Canadian monopoly money) and they wont cover it under my extended GMPP plan. I hope they revised these things to stop leaking all the time. Truck is a 2017 with only 21,000 miles or 34,000km.  Insane. 

[relevante]

On 11/10/2023 at 1:14 PM, relevante said:

 

The process for doing braided lines would be fairly similar, would just have to decide where you wanted to cut off the factory lines and then use AN connectors to join to the braided line, and make sure they were routed and well secured.

 

 

This ended up working well for me. I just cut the factory lines in half in the rubber section, which make them easy to get in and out. Then cut off the aluminum lines in sensible places, flared them, and used 8AN connectors to put it all back together.

 

However, once I did, I realized going hard line all the way was a bad idea with the vibration and flex of the motor mounts. So I pulled the hardline section I added out and replaced it with some Aeroquip hose. Now it looks great and I'm confident it's solid for the long haul. With all the figuring out, it took me quite a bit of time (although still probably less than it would have taken me to fight with the factory lines), but knowing what I know now, I could knock it out really fast. And if my current lines start leaking, I can replace the flex portion in probably half an hour. So I'm happy with the choice.

 

If anyone does want to replace their factory lines and needs lines (part number 86788215), I had already bought new ones before realizing what a pain it was going to be. I paid $95.75 + shipping. If anyone's interested, make me an offer and we'll work something out. I'm near Poughkeepsie, NY, but they're still in the box they were shipped to me in, so I can easily ship them.

Edited December 6, 2023 by relevante

[Mshawn]

On 12/6/2023 at 8:28 AM, relevante said:

 

This ended up working well for me. I just cut the factory lines in half in the rubber section, which make them easy to get in and out. Then cut off the aluminum lines in sensible places, flared them, and used 8AN connectors to put it all back together.

 

However, once I did, I realized going hard line all the way was a bad idea with the vibration and flex of the motor mounts. So I pulled the hardline section I added out and replaced it with some Aeroquip hose. Now it looks great and I'm confident it's solid for the long haul. With all the figuring out, it took me quite a bit of time (although still probably less than it would have taken me to fight with the factory lines), but knowing what I know now, I could knock it out really fast. And if my current lines start leaking, I can replace the flex portion in probably half an hour. So I'm happy with the choice.

 

If anyone does want to replace their factory lines and needs lines (part number 86788215), I had already bought new ones before realizing what a pain it was going to be. I paid $95.75 + shipping. If anyone's interested, make me an offer and we'll work something out. I'm near Poughkeepsie, NY, but they're still in the box they were shipped to me in, so I can easily ship them.

Yes this will do it!! Great job!!

[AJMBLAZER]

Yay…mine is leaking now. 
 

I was reading on another forum where a guy cut off the factory end clip things, used new hose and hose clamped it onto the original fittings. This sounds doable. 

Edited December 8, 2023 by AJMBLAZER

[AJMBLAZER]

Dumb question - what did you guys replace along with the hose?  The GM parts diagram shows gaskets on each end, bolts, and a sensor?

[relevante]

15 minutes ago, AJMBLAZER said:

Dumb question - what did you guys replace along with the hose?  The GM parts diagram shows gaskets on each end, bolts, and a sensor?

 

The gasket and sensor on the engine side comes with the new lines.

[AJMBLAZER]

Ok. I’ll have to get new of those. 

[relevante]

1 minute ago, AJMBLAZER said:

Ok. I’ll have to get new of those. 

 

I bought a set and ended up just modifying my old ones as discussed above. It's part number 86788215. I'm not sure if that part also applies to the 5.3 (I have a 6.2) but if it does, I'll make you a deal!

[AJMBLAZER]

I’m going to try and upgrade to better hoses and connections. I will keep you in mind as a backup though. 

[relevante]

10 minutes ago, AJMBLAZER said:

I’m going to try and upgrade to better hoses and connections. I will keep you in mind as a backup though. 

Good idea. It’s easier and likely better than just replacing them IMO.

[AJMBLAZER]

On 12/10/2023 at 2:33 PM, relevante said:

 

The gasket and sensor on the engine side comes with the new lines.

Dumb question v2.0 - I’m ordering a new sensor and gasket. Did you have trouble with anything for the other end?  GM shows a spring clip, oil cooler connector, and cap.

[relevante]

1 hour ago, AJMBLAZER said:

Dumb question v2.0 - I’m ordering a new sensor and gasket. Did you have trouble with anything for the other end?  GM shows a spring clip, oil cooler connector, and cap.

Everything you need is already on the lines. At least the ones I bought for the 6.2 were that way. You don't get new bolts or spring clips but you can reuse the old ones.

[AJMBLAZER]

Ok. I was just wondering if any of those gave you issues and got mangled or anything. 

[relevante]

19 hours ago, AJMBLAZER said:

Ok. I was just wondering if any of those gave you issues and got mangled or anything. 

 

If you're planning to mod the lines, just start by cutting them in half at the rubber hose and they'll come out and go back in really easily. Then you can do all your cutting and flaring on the bench, reinstall the two sections and then fit the new flex line on the truck. On the other hand, getting them in and out in one piece seemed nearly impossible without taking a bunch of other stuff apart.