Transmission cooling lines? hi or low pressure
 

My question is are the tranny cooler lines (in& out of the radiator) under a high or low preasure. The truck is a 1990 Dakota 3.9 . The rubber hose's that run to the radiator are heat shrunk to the 2.. in and out pipe that are at the bottom of the radiator. Can I cut the hose off to remove the lines from the radiator then add a length of same dia. pipe to the hose at both ends and hose clamp the the new extentions to the new radiator?? Thanks

my 2001 dak 42 trans. the book calls out one of the pressure gauges to be 300 psi. the test for the governor operation shows the highest presure at 280 psi. i can not find a call out for the coolant line pressure. in the chart it calls out the line pressure at 160-270 in rev, which i think is the the highest pressure any where in the trans, but that is internal NOT external. i will make a guess that the coolant line will be 70-90 psi. if i missed something ill get back to you.

not sure on the pressure but I have flared brake lines that are the same size as the trans line connecting my trans lines for my trans cooler to the existing lines. but for piece of mind I used two hose clamps on each end since I was having problems with single hose clamps coming loose.

I checked mine lastnight since the previous owner just had a new rad installed before I bought it...

just has high pressure goodyear rubber hose(rated 200psi) on both with double clamps on both hoses and on both sides(8 clamps total)

Thanks I think thats the way I'll go

i just checked a 1967 727 coronet book it shows the coolant line to be 5-30 psi. my 2001 46re trans shows the converter lube pressure at 60-130 that feeds the coolant line after it goes from the converter to the coolant line. this the highest pressure in this line in rev. other gears are less most 2-57 psi.

Yes ,I'm almost sure that there low pressure,Because my son started the truck up to jump his motorcycle battery,and nothing pumped out of the line to speak of, it was in park but I don't know if that would make a difference. Thanks moe

The cooler is returning the fluid to the transmission, there is some pressure but not the high pressure used to operate the transmission, so the 200 psi hose used is more than adequate for the job. I've seen people use low pressure hose and it tends to balloon after a short periiod.

the trans in the 60s did NOT push fluid to the coolant line in park. ill try to check if the newer trans do the same. i was told that the older trans in police cars setting in park with the engine running and A/C running the trans would over heat. my 2001 dak book shows a 42re in park does NOT run fulid through the coolant line. i think chrysler thinks that if the parts are not turning it doesnt need lube to the bearing. but in the hot summer then the trans can still over heat.

Had a brake in the weather today, And put the radiator in using the method of cutting and extending the hose, by using short metal tubing inside a section of hose. everything went together fine. Ran the truck for about 20 minutes no leeks. Thanks for all the help.