BlownF1

Tried a quick search, and I'm in the process of upgrading my tranny cooler and need to extend the lines...tonight if possible. The rubber hose that came with it isn't marked with anything that tells me the type of hose or rated pressure. I'd like to pick up something locally since the tranny goes in tomorrow. Anyone know what type I should be using or what the pressure in those lines is? Is hi pressure fuel injection hose gonna work?

GreenDemon

Well according to the book:

Drive, Park, or neutral- 55-189 psi
Reverse- 64-324 psi

I would think a metal line would be necessary, but I couldn't really say. Pressure is controlled by a solenoid w/ a valve- pressure will decrease with temp. Hope that helps. You don't want to use a line that's too weak, don't think your tranny would like that...

BlownF1

Thanks for the numbers. The car has had a cooler with rubber lines for 5+ years, so I picked up some high pressure fuel injection hose and will monitor it. Thanks again.

blown94

high pressure fuel line is fine. the numbers hes given you aren't cooler line pressure, those are mainline pressure figures inside the transmission.

GreenDemon

Yes I see they're in a separate circuit but does anyone actually have any other numbers? The manual doesn't say anything about the pressure in those lines. It could be anywhere from near zero to something very high, but I suppose it depends on how much flow GM designed it for and the fluid level as well. Any thoughts?

Eff

Ummm, the 94/95 stock pcm configuration has a maximum line pressure variable which is set at 90psi for the factory. I'm not sure if that will help, appearently line pressure doesn't refer to everything, if Green Demon's numbers are right.

BlownF1

Thanks for the input. While reading the tranny coolers install directions, it suggests that you disconnect the line and feed it into a bucket, start the car and determine which way the fluid flows...I figured since they were suggesting that, it couldn't be too high of a pressure!

I need to call the tranny shop today anyways, so I'll see what they say.