P/S Cooler Location

[GRINCH]

My stock cooler sprung a leak. So I bought a fin type cooler to mount behind the grill. Does anyone see problem having the cooler mounted higher than the pump res. should I plumb the input from the pump to the bottom and return to the pump from the top. My theory is that the fluid will not flow back to res after the motor is shut off.

 

[trikstark5]

IMO, I would plumb the input to the bottom of the cooler. I know when installing vertical oil coolers on hydraulic systems, the input is at the bottom and the top contains the output. I would imagine it would work the same way for a power steering pump.

 

[4X4HIGH]

If you mount the cooler higher than the resevoir it will drain back on you.

 

[boz42]

4x4HIGH is right, it must be lower than the fluid level in the resivior.

 

[GRINCH]

So why don't we have problems with the Factory Oil cooler and add on Tranny coolers? If plumbed with the return at the top wouldn't static pressure keep it from filling the resevoir?

 

[4X4HIGH]

If you mounted the cooler with the fittings facing sideways theoreticaly you would be correct, but now consider the fact that when the engine is off there is no pressure being applied to the pressure side so it will now return from the lower "pressure" side of the cooler.

An engine cooler or tranny cooler doesn't matter as when it returns there is no way for it to spill out the dipstick on either application.

 

[6.2Blazer]

But it's a closed system, so how can it drain back? Sure the fluid could circulate, but it couldn't overfill the reservoir because other fluid in the system would have take the place of any fluid that drained out of the cooler thus keeping it a consistent level. Otherwise you would have air pockets and have to bleed the system everytime you started the engine.

 

[4X4HIGH]

The fluid will return to the resevoir then once full will leak out the breather hole in the cap.

 

[boz42]

I originally mounted my P/S cooler were the top 2-4"s of it was higher than the top of my P/S resevior. Every time you cut the engine off it boiled over. After it quit & all the fluid settled down & the foam was gone, I could top it off & it worked fine. Cut it back off & it boiled over again. I lowered the cooler & never had a problem again.

 

[6.2Blazer]

I still don't understand how this could happen, but I could very well be wrong. Since there is a fixed volume of fluid in the system, the only way the reservoir could overflow when you turned the engine off (by the lines draining back) is if air took the place of the fluid.