The Stovebolt Site Forums The Shop Area The HiPo Shop transmission cooling lines

What are the pros and cons of using all high pressure flex hose to and from the trans and cooler. I am using 350/th400 and the cooler is in the radiator. Dave

Pro for rubber, easy to run

Pro for steel lines (cons for rubber hose), look factory/appropriate, cool better than rubber, longer lasting, easier to support with clips and prevent rubbing, probably higher pressure rated though not likely an issue.

Good post.

"cool better than rubber, longer lasting, easier to support with clips and prevent rubbing, probably higher pressure rated"

And probably cost less. Jeffrey

Thanks guys, that is what I was looking for. Dave

If you spring a leak in a rubber line (something you won't have happen with steel lines) you will trash your transmission before you know that you have a leak. It comes out fast.

I'd use stainless tubing mounted solid to the frame and the radiator, with short braided wire armored flex hoses to the trans to absorb any motor mount movement.
Jerry

Thanks all. Dave

Homer,

Complicated hard lines are not easy to make and if you can do it it showcases your craftsmanship and enhances the appearance of your project.

The stainless tubing that Jerry recommends probably cannot be double flared for common flare connections so AN fittings may be required. Stainless tubing does look very nice, though.

When I restored my '36 Chevy pickup over 40 years ago I used stainless tubing for gas lines and for the vacuum advance line from the carburetor to the distributor and it still looks as good as the day I installed it.

Ray W

I'm using braided flex 6an from th400 to cooler. There are specific fittings that needs to be replaced on the trans to accommodate the braided flex. I haven't decided how to keep the hose separate yet. I'm also using 8an braided flex from fuel tank to pump. The cost really isn't in the hose, as braided flex is relatively inexpensive. You'll bear significant cost in fittings. By flex, I'm assuming it is braided stainless steel over rubber hose that encases a fluid resistant teflon inner hose.

A good trick is to grab a couple drop ceiling hanger wires from the hardware store. they are long, and hold their shape. you can use them to make a template of your steel line in place, then pull it and bend your lines on the bench.

...and Lowes carries them to and they are pretty long.

I suppose if you have the truck disassembled it would be feasible to route steel trans cooler lines, but working underneath the tight confines of an assembled truck often make this impractical. Most trans cooler kits come with rubber line, so the manufacturers must believe it to be adequate. Plus, calculate how old you are, how long you have left to live: modern high-pressure rubber line will probably outlast you.

When building a vehicle from the ground up, I typically use hard line up to the cooler, then rubber line to connect the two. I've never had a rubber line fail.