Turbo-Jet

i will soon be finished replacing all 4 calipers, rotors and rubber lines.

what about the M/C? when is it time to replace? what about a rebuild kit?

Lohkay

From my experience, its all good until the pedal alternates from soft to hard OR when it is still soft even after replacing everything and bleeding.

ED DINAPOLI

Cam,
The master cylinder in my 72 is still the original and has never been rebuit.
I just replaced the master cylinder in my 74 last summer. I did not have it rebuilt because I dont care if the numbers match on the 74. I dont think there is a rule of thumb for how long they last. If the pedal feels ok and it does not leak it is probably ok.
Ed

redvetracr

turbo,
I think you will find (as i did) you can get a rebuilt MC in the $25 range, exchange, and for some crazy reason a "rebuild kit" is more like $35. go figure! ...redvetracr

daniel77350

my replacement MC was $25...thats after the $10 core. So I payed $15 for a MC. Just an idea....Better safe then sorry, and replacing it is pretty darn easy...its just a bit heavy...

Daniel

Barry's70LT1

Hi..
About 10 years ago I replaced the calipers with SS. I did the rubber lines
as well.
My M/C was fine, but since I was in this deep, I picked up a Delco kit for
the M/C. Wasn't expensive, easy to install. Something less to go wrong
in the future.
Now that everything was clean and new, I went with silicone fluid.
Don't believe any of the negative stories about silicone fluid.

Bench bled the M/C, then gravity bled the brakes. (Use rubber hammer for
tapping)
The cover on the M/C had not been opened until last month. I needed to
bleed the rear calipers, since I had them off during the T/A rebuild.

Just my .02 worth.
Barry

LT1driver

Not having any problems then flush, bench bleed and keep it. Always change fluid for best results and longivity every two years. Voice of experience talking here and that is with stainless steel lined. good luck. :cheers:

Jim 77

I am no expert but I think that M/C's don't go bad because of wear or age. I think they go bad because of dirt. When I replaced my old one last year I took it apart, and the parts look pretty good. But there was sludge and other nasty stuff in the piston. I am willing to bet that when I pressed the pedal down to the floor it stirred up the sludge, making the seals unreliable.

My vote is clean it out, or replace it (very easy and $25). If you stir up old dirt while bleeding it could get frustrating.
Jim