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Trans cooler lines?

jekquistk5

jekquistk5

Weld nekid
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What is everyone running for trans cooler lines? I have rubber/steel with hose clamps on my rig and hate them. My dads k5 needs new lines put on before the dune get together. I have done hard lines using brake line before but thats a pain too. I do not want to spend a fortune but will spend a few extra bucks to not have to do this again.
 
I've used the ready made 5/16" brake line to make them up--they usually last only 2-4 years up here though...they now sell nickel/copper tubing that supposedly wont rust at parts stores now..its pricey but is easier to flare and bend,and you'll likely only have to deal with it once..

One truck I had I used 5/16" copper tubing with short rubber sections of proper transmission cooler hose ,to splice them to the OEM ends of the original tubing when the fittings at the radiator didn't want to unscrew and I feared I'd twist the tank right out trying to remove them--and wasn't looking forward to trying to screw them into the fittings at the tranny itself..as long as you "isolate" the copper from the steel tubing and use the correct type hose,you wont have any troubles with it cracking from vibration or electrolosis...the copper might even dissapte heat a bit better than steel too..

I have never used all rubber hose like hydraulic hoses ,though I've been tempted...I think that might not help cool the fluid like metal lines would,and its bulky and hard to route thru tight spots without it chafing or getting burnt on the hot exhaust pipes or manifolds..
 
We use 5/16 steel line and a tubing bender, takes a little time but is reliable and sturdy. If we have the budget we use #6 braided line but with 12 feet of line and associated fittings that adds up and takes as much time as the steel lines to route and cut, install fittings, pull little pieces of wire out of your fingers etc....There is some high quality rubber line on the market such as push lock that can be used, just keep it from chafing anything along it's route and check it seasonally for deterioration.
 
I run Aeroquip Teflon hose and the aeroquip teflon fittings. The biggest concern you have to think about here is temperature. And the fact its tranny fluid.

Go metal, or go PTFE IMO.

Edited to add: Even with braided hose you want to make sure it doesn't chafe. That can still kill braided line.
 
I used 300*/250psi hose and pushloc fittings for mine....found it in Jegs catalog I believe....its in my thread somewhere on exactly what it is....ain't had a leak or blowoff yet.
 
76zimmer said:
I used 300*/250psi hose and pushloc fittings for mine....found it in Jegs catalog I believe....its in my thread somewhere on exactly what it is....ain't had a leak or blowoff yet.
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Think I am just going to run steel. It's cheaper. I'll just have to take more time to route it.
 
i changed the fittings on the trans and used 3/8 steel lines on mine with a trans cooler. i think i still have my old 3/8 lines if you want them
 
919jackass said:
i changed the fittings on the trans and used 3/8 steel lines on mine with a trans cooler. i think i still have my old 3/8 lines if you want them
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Thanks, but I'll just re route new steel line. The original lines were pinched by the axle. Needless to say it's getting new bump stops, and new shocks as well.
 
i changed the fittings on the trans and used 3/8 steel lines on mine with a trans cooler. i think i still have my old 3/8 lines if you want them
 
sorry about the double post passed out briefly when i came to i didn't think i had posted until this morning i see what i did. ops that was the beer posting.

i did bump the size up to the 3/8 you might as well cents your going though the trouble of making new ones a big improvement over the 5/16 ones.
 
GM did use 3/8" lines on some applications factory,not very common though--like some motor homes and big land yachts from the 60's...

I remember saving a pair of tranny cooler lines off a '66 Pontiac Bonneville a friend was scrapping,it had a TH400 with factory 3/8" lines and they were in nice condition still--thats the only car I'd ever seen them on!...

3/8" tubing is a lot thicker than the 5/16" and allows for more flow,and wont rust thru as quickly--but are a bear to bend, compared to the 5/16" ones...
 
Going to be putting some trans cooler lines on my 78 soon. Mine bent and twisted when i took a wrench to em. Got some i got from the junkyard hopefully they will fit!

Any tips/ tricks to installing em? Will ATF come gushing out when i remove the end attached to the trans?
 
Some ATF will likely drain out of the lines and the cooler ,but not much if any should come out of the tranny fittings..have a pan ready to catch any spillage..most likely only a pint or so will come out of the cooler and lines..

Once I replaced a vacuum modulator on a TH350,and wasn't ready for any fluid to come gushing out..there wasn't much that did,but it was a direct hit to the face and eyeballs when I pulled the modulator out--and my driveway got a nice stain that took months to fade away..:doah:
 
diesel4me said:
Some ATF will likely drain out of the lines and the cooler ,but not much if any should come out of the tranny fittings..have a pan ready to catch any spillage..most likely only a pint or so will come out of the cooler and lines..

Once I replaced a vacuum modulator on a TH350,and wasn't ready for any fluid to come gushing out..there wasn't much that did,but it was a direct hit to the face and eyeballs when I pulled the modulator out--and my driveway got a nice stain that took months to fade away..:doah:
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Do i need any special tools to get to the fitting to disconnect it on the trans?? I was able to get a 1/2 wrench on it but it wasnt a good fit and i had no room to break put some leverage on it and break it loose?

Is there any such thing as "flexible lines"?
 
The lines do suck to get at,at the tranny fittings...best way to get them off if your replacing the lines is to saw them off flush with the line nut (or chop them off with side cutters ,etc) then you can use a 6 point socket on the line nut--or a flare wrench--you may have to use a box end wrench to keep the adapter fitting from unscrewing from the tramsmission though,its best not to take them out unless you had too for some reason..

I sometimes leave about 6" of the old line at the tranny if its in decent shape,usually they get oiled by engine or tranny seepage there and dont rust,so I use a tubing cutter to cut them off ,then join the new lines with compression fittings ,or flare the end of the cut lines and use a union fitting..
I've only had one spring a leak near the tranny before..

There is "flexible" hose but its either braided rubber or rubber with stainless steel mesh jacketing you can use--or hyrdaulic hose..personally I trust metal more than all rubber,but I guess its OK as long as you use hose rated for the temparatures and pressures it'll be subjected too..
 
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