Author Topic: MC residual valve  (Read 1063 times)

Offline bc3j

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MC residual valve
« on: November 24, 2015 - 05:16:19 PM »
Looking for thoughts on this...Since the mid 1970s Mopar eliminated the residual valve in all their master cylinders and then used wheel cylinders with expanders to prevent air entry into the system for a disc/drum brakes. I called Wilwood for their input and was told none of their MCs come with residual valves and using the newer wheel cylinders is correct and no residual valves are needed. The Disc-O-Tech article also mentions the elimination of residual valves.

I'm currently looking at a Right Stuff 15/16" MC, which does not have any residual valves. Wilwood stated only if the MC is mounted below the level of the calipers would a residual valve be required for both front and rear brakes.

Absent any compelling info, that's the route I plan on taking. Actually, I'm not sure if my current 1" bore MC has a residual valve and the brakes are solid now and I do have new wheel cylinders with the expanders.
Thoughts?




Offline Chryco Psycho

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Re: MC residual valve
« Reply #1 on: November 26, 2015 - 10:29:13 PM »
Brakes are solid now ? Solid good or solid locked up ?
 I do not see a whole lot of difference between the 15/16 & 1" MC except the pedal travel will be a bit more with a softer feel using the 15/16 MC

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Offline bc3j

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MC residual valve
« Reply #2 on: November 27, 2015 - 12:15:55 PM »
Brakes are good. Difficult to lock fronts and I get a chirp out of the rears once in every ten panic stops. Brake pedal has 3" of movement and starts 7" off the floor. Want to go to 15/16" for a little more line pressure to help the fronts to lock. Software program shows a 13.7% increase in line pressure with a 15/16" MC. That's the primary reason for the MC change.
« Last Edit: November 27, 2015 - 12:18:21 PM by bc3j »