maniago
Well Known Member
O-rings
Kinda an old thread, but as I'm getting close to finishing it up, just revisiting it as its time to load up the brake reservoir.
That said, with respect to Orings used in our systems, at least for my Matco brakes, those are Buna type seals. The below link is a good treatise on the Buna vs Viton in case one was thinking of changing.
https://www.humphrey-products.com/content/viton-vs-buna-which-seal-for-your-applications
In reviewing it, I knew Viton had a better high temp resistance (which goes nicely with ATF), but wasnt aware of the low temps. Despite high temp braking, I can see the trade off in sticking with Buna so no fluid leaks out at high altitudes (ie low temps) one might see there.
Also, heres a great table of all the typical oring materials and specs - note the compatible and non-compatible columns (I think the aircraft brake fluid note is wrong since we know those fluids are petroleum based (like ATF!), not glycol based as auto brake fluid is)
https://www.marcorubber.com/o-ring-material-quick-reference.htm
If you were so inclined to go Dot3 Glycol, Matco does sell an EPDM conversion oring kit for that. http://www.matcomfg.com/catalog.html?Tp=6&adv_search[4]=0&adv_search[keywords]=epdm&sbT=Go
Kinda an old thread, but as I'm getting close to finishing it up, just revisiting it as its time to load up the brake reservoir.
That said, with respect to Orings used in our systems, at least for my Matco brakes, those are Buna type seals. The below link is a good treatise on the Buna vs Viton in case one was thinking of changing.
https://www.humphrey-products.com/content/viton-vs-buna-which-seal-for-your-applications
In reviewing it, I knew Viton had a better high temp resistance (which goes nicely with ATF), but wasnt aware of the low temps. Despite high temp braking, I can see the trade off in sticking with Buna so no fluid leaks out at high altitudes (ie low temps) one might see there.
Also, heres a great table of all the typical oring materials and specs - note the compatible and non-compatible columns (I think the aircraft brake fluid note is wrong since we know those fluids are petroleum based (like ATF!), not glycol based as auto brake fluid is)
https://www.marcorubber.com/o-ring-material-quick-reference.htm
If you were so inclined to go Dot3 Glycol, Matco does sell an EPDM conversion oring kit for that. http://www.matcomfg.com/catalog.html?Tp=6&adv_search[4]=0&adv_search[keywords]=epdm&sbT=Go
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