Hey everyone,I am trying to find out the o-ring type/size for a 99 gmc jimmy 4.3l 4x4 w/power steering cooler. The Power steering high pressure hose o-ring fitting that screws into the power steering pump itself. I have recently installed everything completely new on this system and added a p.s. filter inline,but,I am having to replace the new cardone pump because of whining noises that no matter what I did wouldn't quit,( I did vacuum it at 25 psi 4 times) I am replacing it with a brand new gm power steering pump from rock auto and I'm sure I need to replace that o-ring even though the new high pressure line came with a new one and has only been driven with about 80 miles n looks fine to the eye.From what I can find out it says it has an 16mm an a 18mm o-ring on the ends. Is there a best brand/type of o-ring to use? Thanks for any info!

 

The threads may be that size, but the o-ring is much smaller. I'd be surprised if the new pump doesn't come with one.

 

thank you for you reply,I thought new o rings would have came with the new pump too,but they did not,I've been online all morning trying to find the correct size or part number for it with no luck so far...

 

It should be approximately 3/8" ID x 1/16" thickness. Take the old one to an auto parts store and they should be able to match it. Otherwise, a whole assortment of them is like 15 bucks, and is pretty handy to have if you do much automotive work.

 

Thank you,I've got an assortment already but its gotten low over the years,so I will probably buy another assortment with that specific size in it,thank you again for your help,much appreciated

 

No problem. I hope it helps. Remember, though, that size is approximate. Just use the one that fits snugly on the little nipple on the end of the metal line.

 

Okay, I gotcha.. I just wondering what kind does it need to be made from? I'm thinking hydraulic type o rings?? What do you think??

 

It's nothing special. Standard Buna ones should be fine.

 

Okay,thank you a lot!! I didnt know there were so many different ways they made o rings till today,lol.... much appreciated!!

 

Happy to help. Let us know how it works out.