Transmission cooler line options

I replaced the tranny in my 92 5.0L k1500 and my old cooler lines were full of the same junk as my old tranny and they are trashed. I have been to two parts stores that both say they cant even order pre bent lines from GM. Does anyone know if thats the case or not(parts stores i have learned usually dont have the brightest people working there) Also i did get some same diameter brake line and tried bending them into the lines myself and thats not going to work. Trying to bend that stuff underneath and around everything is way to much of a pain and almost impossible. So what are all my options on this one? Whats would be the easiest thing to do?

I use 3/8 rubber tranny line myself...

I have had luck going to a place that specializes in hydraulic lines. They were able to cut off the rubber part of the line and build me a new rubber line that used a compression fitting over the old metal line. No leaks and has been on my truck for over 5 years.

If the metal lines are in good shape, this can be an option.

//2000CAYukon

I have considered both those options because that would be so much more easy. But the only problem i have with them is that eventually those lines that are rubber will crack or if they are rubbing on anything its going to rub a hole right in them. Also the rubber line doesnt disperse the heat either like the steel line does. That steel line almost acts as radiator itself and kinda somewhat pre cools the oil before it even reaches the radiator(thus resulting in lower tranny oil temps then if i used rubber hose) But thats just my thoughts, i may be totally off base i dono thats why i came here for some help :wink:

I have considered both those options because that would be so much more easy. But the only problem i have with them is that eventually those lines that are rubber will crack or if they are rubbing on anything its going to rub a hole right in them. Also the rubber line doesnt disperse the heat either like the steel line does. That steel line almost acts as radiator itself. But thats just my thoughts, i may be totally off base i dono thats why i came here for some help :wink:

The lines I got from the Hydraulic shop were rated very high as far as temp and psi so I don't think you have to worry about them cracking any time soon. Can't hurt to check out a shop if you can find one in your area that makes custom hydraulic lines.

//2000CAYukon

Sorry i wasnt really specific enough on my last post. I am worried about them cracking due to dry rot with it being rubber and all, Not due to to much psi. And im not worried about the actual temp rating of the line itself thats no problem to find high enough rated stuff, im worried about the temp of the tranny oil. See with steel lines that line absorbs much of the heat from the oil and then driving down the road the cool air contacting the steel line kinda pre cools it a little before it gets to the actual cooler. I really dono how many degrees it brings it down. I dono if its enough to even make a difference. I do know that hydraulic lines would be much much more simple then trying to bend all that steel line. Thats a pain in my A$$ trying to bend it with a tubing bender and trying to get the stuff in and out and what not. I really dono what to do part of me wants to just go to the hydraulic lines for the convienence but the other part of me thinks that GM used one piece steel lines for a reason and i should just keep it that way. So i still really dono what to do hahaha :screwy:

Come on guys. Need more input please :)

The amount of cooling you get from the brief period the fluid runs through a steel line is minimal compared to the fluid running through an actual cooler. Sorry, but keeping it steel won't make that much difference in the lifespan of the tranny. The only reason GM used the steel/rubber combo is to make it fast & easy for the assembly line to hook it up and be reliable for the warranty term while giving enough flexibility to account for production variance. To me simpler is better.

It is inevitable that the OEM crimped steel/rubber lines will leak, whether they be for oil, tranny fluid, etc. All 4 are leaking on my '95. I've gone to cutting the original crimped hoses off and using a flaring tool to create a bubble flare to use with standard tranny fluid hose and a screw clamp.

Dunno where you live at but dry rotting of oil lines is a very long-term problem in general (up to 10 years). If you want to protect them further, you can install some braided hose cover or the split-type engine wiring harness plastic over them. And tie them away from other heat sources.

If you're tranny fluid is getting too hot and you don't have one already, then consider an external tranny fluid cooler.

Hope this helps!

If you have new lines built at a hydraulic hose shop, I wouldn't worry about rotting, bursting or heat damage to the hoses. The hoses usually have a braded cover and are designed for industrial use and are tested and used under conditions that your truck will never see. As far as chafing against the frame ect., just route and secure the lines using clamps or even heavy nylon wire ties. The hoses would probably outlast the truck.