Cane

hey, I went in the plumbing section at home depot yesterday in order to find a fitting for this power steering cooler I got from a 04 WJ. I eyeballed it and got a 3/8 fitting that looks like this. It was just a tad bit too large, like less than a millimeter.

by looking around the forum, I found a thread with the exact info I needed, and from what they said, the size is indeed 3/8". so I'm guessing the plumbing fitting's threads or design don't match. i posted a pic below of the cooler line setup.

I got the lines from the junk yard, but I don't have the little o-rings needed, so my question is, either where can I find the proper o-rings (other than the dealer and ideally for cheap, I don't have 5$ per o-ring to pay for this) and/or, where can I find a proper fitting to avoid having to find the seals?

thanks

dave1123

Yes, I don't know what actual size the thread is, but it's for 3/8 hydraulic tubing. Plumbing fittings are taper pipes sizes and are totally different. Taper pipe sizes are designed to lock together and be self sealing when tight. Hydraulic tube fittings are straight thread and designed to seal with a gasket or flare on the tubing. Any hydraulics repair supplier or heavy construction repair shop can sell you the o-rings. You may find the right SIZE at a hardware store, but usually they are not neoprene or nitrile for use with oil.

If you can't find a hydraulics shop, try a farm tractor repair place. Remember the tubing seals on the o-ring, not on the thread. It's sort-of a large brake tube fitting that uses an o-ring instead of a flare. Chances are the tubing is aluminum which is difficult to flare.

O-rings are cheap. I worked in hydraulic maintenance of machine tools and the most expensive o-rings I ever bought were Buna-N and cost me about 50 cents each. Of course that was 20 years ago.

Cane

alright thanks a lot for the information. the guy in the plumbign section said something about not having the same sizes even if the numbers match, so that explains it.

I'll try to find a proper store or shop for this then. last thing if I might, what do you recomment, getting the o-ring and use the old bolt/screw and line or a new hydraulic fitting looking like the one I posted?

thanks again

dave1123

It's very hard to tell what you actually need without seeing it in the flesh, I think pump delivery pressure is around 1000 psi, but return pressure who knows. I'd have to see the system to make any recommendations. What does that pipe screw into? What are the fittings on the cooler? If I were designing the system, I'd put the cooler in the return line, but who knows what Mopar did? If the return pressure is around 40 psi, you can used rubber hose and clamps.

Cane

looks like this :

dave1123

Are you sure that's a power steering cooler? It looks like an auxiliary trans cooler to me.

Cane

yep I double checked the lines. the actual trans cooler was as big as an XJ radiator, and behind that was the WJ radiator.

here for example :

http://www.ebay.co.uk/itm/JEEP-GRAND...AAAOSw9N1Vujra

dave1123

Huh! That's weird. My 00 WJ has a trans cooler, then the A/C condenser, then the radiator. The trans cooler is about the same size as your P/S cooler judging by the doorknob in your picture. The A/C condenser is bare unpainted aluminum. I don't have a P/S cooler at all.

Tanner Price

Didn't mean to post here

jon-d

i know its an older thread, but to add to the question of finding an O-ring Mcmastercar or Granger sells them. use a caliper to measure the size. a buddy of mine who does aftermarket work on motorcycles picked up a bag of O-rings for rear shocks for about 2 bucks. normally the dealer sells the seal assembly with the Oring in it for 30 ea. saved his customers some money.

dave1123

The same thing goes for grade 8 bolts. If you buy them at a hardware store or auto shop, you pay big bucks! Buy them at an industrial supply house and they sell them BY THE POUND! All their bolts sell by weight and grade, not size or quantity.

When I was working as a toolmaker, my boss decided it was MY job to maintain 3 vertical milling machines that were hydraulic powered. He sent me to Vickers for training in hydraulics. I learned just about all there is to know about 0-rings and how to design devices using them, cutting the lands and grooves and sizes to use where. 0-rings were the answer to leaks in aircraft engines and helped us win WWII.

For instance, I know that 0-ring fitting on your transcooler or P/S cooler seals on the 0-ring BUT the end of the tube bottoms out in the fitting so you don't crush the 0-ring more that it's supposed to be. You have to have the mating fitting to use it properly. Hose and clamps are only good to about 50 psi IF the tube has a bubble flare on it so it can't slide off.

In the 50s, Chrysler power steering pumps put out around 1200 psi and were so good many people used them for plow lifts. IDK what they put out now.