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View Full Version : Brakes: master cylinder for disc brake conversion.



oldguy
10-08-2011, 08:48 PM
61 Hawk with a disc brake conversion kit (looks exactly like a turner kit) and the master cylinder looks like the one on their page http://www.turnerbrake.com/mcbrackets.html
MC went bad and I replaced it using the part number on the old one. Now the pedal stroke is too long. Stops the car, but hits the floor before it gets hard. Does anyone know the part number, or application,of that MC?

sbca96
10-08-2011, 09:13 PM
Sounds like it wasnt properly bled after it was installed. MC with same part number
should have the same results. If not, I suspect air in the lines.

Tom

oldguy
10-08-2011, 09:21 PM
Me too, that's why I spent all day bleeding. Upon double checking, it seems there are 2 different mc's that that number crosses to.
For some *&^(% reason, they can't back track the number to tell me what it fits, bore size, etc. I'm not in the mood to buy the "other" one and install it to see if it works. Thought I'd try to find out what does work and go that route.

PS, the pedal doesn't "pump up" like it has air in it, just stops about 1/2 inch from the floor, like the piston is too small.

JoeHall
10-08-2011, 10:24 PM
It is easy enough to peel the rubber boot back on the front end of the MC and check piston size. A 1" is what you're looking for. I have found it helpful to leave the original residual pressure valve in the MC, and also installing the in-line 2 & 10 PSI ones. That definitely makes mine work better, as far as pedal height, firmness and stopping power. It may be the two MC versions are with and without the internal residual valve.
If you feel squeamish about that, you might try replacing the in-line valves. The ones made in China are junk, and the Wilwoods are not much better. I would suggest SSBC or Russell, in that order.

oldguy
10-10-2011, 10:47 PM
It was a caso problem. Bought a rebuilt that was defective. Bought a new one this time. Still having trouble bleeding the brakes, but I'm working on it.