Crossover Tube O-rings demystified

[BigCars4Ever]

So I got in my Ford crossover tube o-rings, PN 391533-S100, and made some quick measurements.
First, these are standard round o-rings. Based on taste they are plain rubber but I will do a solvent test on the old ones to verify.
Second, They are not a size you can get from a hardware store. The ID is 0.986" with a cross section width of 0.116".

That crosses to a Parker 3-913 or a AS568A-913. The 913 seems to be a common size identifier
Quick search on MSC yields http://www.mscdirect.com/browse/tn/Hardware/Machine-Equipment-Hardware/O-Rings-X-Rings-Cord-Stock/O-Rings?navid=12108900#navid=121 08900+4287872397
I paid $2.40 a piece!

[BigCars4Ever]

Solvent testing seems to indicate that the o-rings from Ford are Buna N (nitrile) based on an acetone soak which would have not affected the Viton.

[chief455]

Good info, thanks!

[slickster]

Good job. These are good to just have around. Original rings can be very brittle and crack easily and you don't wanna play with a cooling system at all!!!.

[grandepau00]

I used regular metric o-rings. I think they were 22mmX2mm but I'll double check. But I've had no issue with leaks.

Sent from my XT1031 using Tapatalk

[Roadwarrior]

This thread should be a sticky. :dunno:

[Zack]

Buy them, install them, verify they work, then post info.
It's the right thing to do. :D

[RF Overlord]

That crosses to a Parker 3-913 or a AS568A-913. I paid $2.40 a piece!McMaster-Carr part # 9751K124. Package of 100 for $10.53.

Or you can get silicone part # 9396K433. Package of 25 for $7.67

[martyo]

McMaster-Carr part # 9751K124. Package of 100 for $10.53.

Or you can get silicone part # 9396K433. Package of 25 for $7.67

Yep and have em in a day unless you live in da boonies!

[BigCars4Ever]

I will be ordering these soon because I'll be getting my riser adapters and cooling kit plugs soon and I designed them to use the same o-ring.

[jimlam56]

Thanks Ron!

[massacre]

Good info thanks!