[crg]

i think ive searched to the end of the inter webs looking for a replacement gasket for my 964 hydraulic pump. anyone have any ideas or experience sourcing EPDM gaskets for these?
the pump runs fine, im getting a leak between the motor and the pump.
thanks

[Vicegrip]

I make my own o rings for many things things. Find something close in cross section but larger in diameter. Many cross sections are sold by the foot too.
Cut out a section with a fresh new single edge razor blade to adjust diameter. Make the cuts straight up and down and center out in the circle. Using the end location groove helps if it is accessible. Wipe the new blade with solvent first as any oils will inhibit adhesion. Put a tiny drop of super glue on one end of the o ring then gently and accurately place the ends together. Doing this in a fitted grove helps. Hold for 10 seconds or so then leave it for a min or two. Clean off any excess glue and install in the device. Never ever once had a home made o ring seal fail.

[crg]

thanks Vice..where do you source your rubber by the foot? (there prob a joke there somewhere)

[Charlie Stylianos]

McMaster-Carr sells EPDM orings and cord by the foot.

https://www.mcmaster.com/o-rings/mat...l~epdm-rubber/

[cmartin]

One source https://www.mcmaster.com/materials/thickness~1-32/ just guessed at thickness

[ducatithunder]

Mcmaster Carr. You can buy oring stock by the foot. Just make sure you get the right material. Are you certain that this oring is EPDM? Buna/Viton is for oil service and EPDM is good for most other applications except oil. Measure the OD and you should be able to get a metric size. They also have the loctite glue for orings ... Loctite 404. Its very similar to superglue. If you can find a local Fastenal you could bring the oil unbroken oring in and get it measured. There is a simple tool to measure the thickness and circumference to get the standard sizing number to order the right premade size. IF you order the stock make sure you think about the durometer rating, not to hard or to soft. Unless you know it i would order middle of the road for hardness. We make orings at work all the time. If done right they are usually bullet proof. Be careful not to have the oring twisted or rolled when glueing it. GL

[crg]

thanks folks but the seal isnt an O ring its a flat gasket/seal like you would find on an oil filter. An O ring may work but I'd prefer to use the orginal type.

ref EPDM or SBR rubber- since it is exposed to brake fluid EPDM or SBR is the material that wont break down like viton, buna, and others. Also, i contacted permatex and they dont recommend any of thier gassket makers be exposed to brake fluid.

handy chart for rubber compatibility-
https://mykin.com/rubber-chemical-resistance-chart

[ducatithunder]

See attached ...

https://www.mcmaster.com/rubber-gask...una-n-o-rings/

you can also order square roll gasket and glue similarly as started before. Mcmaster is going to be your best bet.

[crg]

Originally Posted by ducatithunder

See attached ...

https://www.mcmaster.com/rubber-gask...una-n-o-rings/

you can also order square roll gasket and glue similarly as started before. Mcmaster is going to be your best bet.

mcmasters it's going to have to be. i am going to stick with EPDM though, below is from mcmasters website..just a friendly fyi

"Made of Buna-N, these O-rings resist grease, hydraulic oil, and motor oil—plus mild chemicals and water. However, Buna-N is not for use with brake fluid."

[Vicegrip]

Originally Posted by crg

thanks Vice..where do you source your rubber by the foot? (there prob a joke there somewhere)

Looks like you got your answers! As said you can get o ring material in many cross section profiles. Get some extra and practice a bit.