93

Having trouble getting the piston out of the master. Any tricks?

I removed the white plastic sensor (don’t think that matters) and I cannot seem to get the thing to budge. Pushing on the pedal just leaks fluid around it…

 

I’m trying to do this leaving the master on the car. I see others removed the brake lines. Is this required (ie the tips of the flare interferes with removing the piston?)?

Also on the 93 master I can directly see the clip and spring…other examples on this forum the spring is accessed from the “back” after fully removing the piston. There is no slot for me to be able to grab mentioned in other posts.

I’ll try pulling the lines next and see if that makes a diff…

 

Well I removed the master. Tried the whole FSM slam it down on a piece of wood thing…. That didn’t work.

Found a bolt that was able to just thread into the c clip and finally after some mallet whacks it came out.





eww.. I am cleaning it up but wondering about this master. I at least want to put new o rings on the proportioning valve. Can I use regular black o-rings? I also have ac o-rings (green) if those would work…

 

If it was working before you took it apart I would just clean it as best you can and reuse the o-rings you have as long as the o-rings are not brittle. I would not use just any o-ring on something as important as the brake system.
I wouldn't know where to start looking for a rebuild kit.

 

I'm torn now and overthinking... I'm wondering if it's worth even putting the bias spring in this master since it appears to be original to the car with 30+ year old seals. I know the new ones are "cheap", but if the actual plunger part of the master looks or is anything like the proportioning valve is it worth me going through the trouble on this master? I'm putting in some $$$ fluid so if the thing blows out I'm going to be pretty PO'd. I wasn't considering replacing the master since I was trying to do the spring swap "on car" and it appeared to be fine...but now I've cracked all the lines, need to bench bleed etc... so a lot more work for an old master.

From the design of the proportioning valve I can see how fluid could "sit" outside of the areas where the fluid is actively flowing....and no amount of "flushing" would clean it out. The plunger portion/cylinder I am betting doesn't have that "goo" since fluid freely circulates but the seals may be questionable...

I can get a duralast master here by tomorrow for ~$160...I would keep my current master to potentially rebuild in the future... Duralast because autozone is local and even one store has it in stock so I have a prayer about running there if it failed.

I guess I'm screaming into the void here, as it's my decision, but if anyone has any thoughts...

 

I recently did the brake inspection and on the brake test stand they asked me to push the pedal hard and it was very difficult to lock the rear so I assumed the bias was not right and just bought a bias spring. I’ve watched a video at youtu.be/ISmtv_qEEbo . the channel is E.T. Garage maybe this helps you. this thread will help me too but didn’t have time to read it through yet

 

Beware it is different by year, I think I saw that video too desperately trying to figure out what I was doing wrong (I wasn’t). The earlier masters the proportioning valve is in there the other way around so there is something you can easily hook to to extract it. My proportioning valve/piston was VERY stuck and nasty…the only way I could get it out was a bolt used as a puller.

It’s a gut punch but I just decided to buy the Dorman master I mentioned. I think my master may have been weeping a little based on the gunk where it mounted so probably needed to be done.

I doubt your bias spring would cause that (?) but maybe…I would think it more likely the MC itself if you have rear braking issues.

Hopefully I can document a clean install for others.