Where to Get Power Steering Box Return Nipple O-Rings?

[PurpleBeeper]

Does anyone know where to get the correct O-rings for the power steering box low-pressure return line nipple? I don't want to guess about exact thickness and/or compatibility with power steering fluid. There are two of them and they go right behind this nipple (extension pointing at nipple in picture). The o-rings sandwich between this "nipple fitting/housing" and the power steering gear box itself. Maybe a member on this site? THANK YOU

 

[69b3rt]

I have gone the expensive route and purchased a complete seal kit for steering gear.

 

[69a100]

You should be able to get one from your local NAPA dealer. They got all different sizes. Good Luck

 

[PurpleBeeper]

You should be able to get one from your local NAPA dealer. They got all different sizes. Good Luck

Thanks 69.... I bought a whole box of O-rings from Advance this weekend. This nipple is still leaking just a little bit. I'm thinking either the rubber isn't compatible with p/s fluid (Advance didn't know if they're viton, HNBR or whatever). I'm also unsure how thick the O-rings need to be to seal properly. My little o-ring kit only had one thickness of the particular o-ring that went into the smaller of the two holes on the nipple piece...maybe what I have now is slightly too thin?

 

[Mopars & Missiles]

Measure the old o'ring thickness, O.D., and I.D. with a pair of calipers. If you have a Hydraulics shop nearby, they will have every size, shape, and thickness of O'ring ever made. Take yours in to them and I'll bet they can match it up perfectly. Added plus, they will also know what material it is made of.

 

[PurpleBeeper]

I found this online. TFE/P (Aflas) seems to have the chemical resistance for power steering fluid, but I don't like the cold flexibility at 0C (32F). I mean, it should be flexing once installed, but that would mean it gets brittle in the winter & might crack due to vibration.
http://www.fluidseals.com.au/o-ring_application_guide.php

Aflas® (Tetrafluoroethelene propylene - TFE/P) Aflas® is Asahi Glass Co. trade name for a non-conventional fluoroelastomer (FKM) material which has a different chemical structure than other FKM’s. It has significant advantages over FKM’s, Aflas® exhibits excellent heat resistance; 3 months @ 230°C, 30 days @ 260°C and intermittent tolerance @ +300°C. Heat Resistance - up to 300°C
Cold Flexibility - down to 0°C


OK WITH: Oils and lubricants, hydraulic fluids, brake fluids, transmission fluids, power steering fluids, sour oil and gas, amine corrosion inhibitors, ozone and weathering, solvents, steam and hot water, acids, bases, oxidizing agents, bleaches, pulp and paper liquors, insecticides, herbicides, gamma radiation and alcohols.

NOT OK WITH: High aromatic fluids (Toluene), non-polar solvents, ethers, ketones, some chlorinated solvents, organic acetates, most Freon’s and acetic acid

 

[PurpleBeeper]

Also found this on polyacrylate seals online.
http://www.manuf-rubber.com/pdf/Material-Guide.pdf

Polyacrylate

Automatic Transmission

Water, Toluene,

Automatic transmission seals.

Fluid, Power Steering

Engine Coolant

meets many automotive

Duro: 70 Standard

Fluid

Acetone

specifications.

Temperature: -20° To 350°

 

[PurpleBeeper]

The parts store "hard black rubber" O-rings from Advance lasted all of two days. This tells me that I've found my problem, but not the correct rubber o-ring material to hold up to power steering fluid.

 

[PurpleBeeper]

Well, it appears that ACM rubber (aka ethlyl-acrylate / aka polyacrylate) is the rubber of choice for power steering systems with automotive OEM's. However, finding someone that would sell me less than a 1000 of each size was tough.

So..... I took a more direct root & just called up Steer & Gear. They sold me a set for $5. If their o-rings weren't OK with power steering fluid, they would have figured that out loooooong ago. I'm sure they'll work & that's worth $5 to me for sure.

 

[themechanic]

Try Rock Auto.