Finally got my old frame machine's hydraulic pump to hold pressure after it blew a seal last month

3 comments

3 Comments

I ended up going with a polyurethane seal from a local hydraulic shop, which was a total pain to track down but worth it. @abbychen, you might want to try that route if the auto parts store stuff doesn't hold up long term. The poly seal was a bit stiffer to press in but it seated way better than the rubber one I tried first. After bleeding the system a few times, it's been holding steady for two weeks now with no weeping at all. Just make sure you clean the groove really well before you seat the new one, because any leftover gunk will mess with the seal.

abbychen2mo ago

What seal did you end up using for the replacement?

morgan5122mo ago

Oh man, @abbychen, you are reading my mind because I just went through this. Did you also find the original part was basically impossible to get? I had to go with the Fel-Pro blue silicone one from the auto parts store. It was the only thing in stock and honestly, it's holding up way better than I thought it would. The install was a total pain but once it seated, it sealed perfectly. No leaks at all now.