Tranny cooler lines.
 

Where's the best place to get tranny cooler lines from my Th350 to the radiator, supply and return. Would I be better of getting prebent or bending my own?

depends what ya wanna do, you can buy them for like 40 bucks out of lmc i think i dont know if they are prebent or not, or you can buy them at checkers i paid 14 dollars for both i think and i bent them myself

If the engine is in the truck, you'll end up bending the prebent ones to where they look like $10 home made ones.
If you are carefull, you can bend them yourself and improve the whoole design. On mine I have 8 inch lines off the tranny, then a union fitting and then the rest of the way to the rad. This is awsome becouse I can disconnect the lines on my tranny in no time flat and speed up a tranny removal.

I was leaning towards bending my own, it'll give me an excuse to buy some more tools.:D

Rubber hose
 

Is it possible to use rubber/braided hose for trans cooler lines?
That would seem to simplifiy this considerably. As long as the lines are kept away from high heat (which they should be anyway) and that the pressure is not too high I don't see a problem with hose instead of metal tubing.

i bent my own wasnt to bad

My dads old car, the po used rubber hoses for tranny lines & they got cut or burnt & they puked fluid. I think braided would be just fine if routed correctly but I also think that steel allows the fluid to cool a bit on its trip to the rad. As for the best cooler lines - I'm with Longhorn Man. On my car I put unions a foot from the tranny & it makes life wayyyyy easier when dropping the tranny. Get the prebent ones cause the home ones look terrible. I've good stuff about in-line tube.

I just went through this. decided to go with rubber hydralic hose. Was pricey, went with all good stuff. came to 67 bucks, canadian. well worth it, and routing was easy. i really like em. my 2 cents
dale

I just redid my lines off of a t400. I used the good quality transmission cooler grade rubber hose. I think it cost me 48 bucks. One thing that I thought was significant. The Truck has a 6.2 diesel and had both an "IN Radiator" cooler and an external cooler. The External cooler was disconnected so all the cooling came from the 'In radiator" cooler. The dang thing was overheating the engine all the time on hills, even when empty. Of course it weighs 7500 pounds empty.
Point is, when I redid the trany cooler lines I only used the external cooler and abandoned the radiator one. My overheating problem disappeared and the tranny, which has a temp guage, stays much cooler. I thought the problem was my fan clutch but it might be that the radiator wasn't heating the air enough to make the fan clutch kick in.

Anyway, I recommend the rubber hose. That is what I replaced and it held up in Phoenix before I bought it. I also recomend an external cooler rather than the radiator type.

Hope this babble helps

Are the stock lines 5/16 or 3/8 for the TH350 ?:bowtie:

3/8

Re: Rubber hose
 

I had mine made at a Hydraulic shop. I had these made up after a rubber hose line came undone 16 miles up in the mountains camping on MT. Charleston outside of Vegas. 107 degrees outside and we walked out. I did the measurements, and told the guy what I wanted them made for. He cut and built me a set of heavy duty ones. Rubber coated steel braiding. The ends are pre-bent at the tranny and radiator, and thread right into my tranny cooler also. I then ran solid metal lines along the frame.
It's been so many years ago, I forgot the cost. But it seems it was in the $50.00 range, for the four of them.

What range of pressures are in the cooler lines?

Seemed to me the pressure inside could get high 200# or so, but in retrospect I don't think the tubes in the radiator could tolerate that kind of pressure. The biggest enemy is the heat, if you use fuel line the heat will eat it up in short order. So if you use rubber, make sure it is rated for the heat (hydraulic hose). I would recommend bending your own. It is not difficult and is kind of fun. When you need help on the bending, figuring out how to measure your bends, re post. There is an excellent article around here somewhere, or I/other members can point you in the right direction.