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Re: Master Cylinder Swap

Posted: July 25, 2014, 9:41 pm
by Toyz
That thought entered my mind but I dismissed it since it sounded as if it worked well before setting. If it is a drum/drum setup, it should have had 10 psi residual valves in both ports , which SHOULD have caused noticeable caliper drag from the start.
Paul

Re: Master Cylinder Swap

Posted: July 25, 2014, 9:45 pm
by ICEMAN6166
does the pressure relieve itself when the truck sits overnight or does the calipers stay on until you crack a bleeder or line

Re: Master Cylinder Swap

Posted: July 25, 2014, 9:50 pm
by longcabjohn
Open line where it goes into the rubber hose, if brakes do not retact the rubber hose has gone bad.


Johnny

Re: Master Cylinder Swap

Posted: July 31, 2014, 11:19 am
by 69supercj
Got the new M/C installed and the brakes work good, have a "good" pedal right off and a real good pedal after one pump. No leaks at any of the fittings BUT the darned thing is leaking around the cap. I noticed that the top lip of the M/C was a wee bit pitted and came within a knats ass of turning it upside down and surfacing it on some 100 grit wet/dry but decided to go with it. Now I guess I'll have to try to smooth it out with some JB Weld. Other then that, all works well and no more drag!!!

Re: Master Cylinder Swap

Posted: July 31, 2014, 4:35 pm
by 69supercj
Well the JB weld didn't work so I took the M/C back off and ordered a new one. Hopefully it will be of better quality then the rebuilt unit that I had. :x

Re: Master Cylinder Swap

Posted: July 31, 2014, 4:59 pm
by ICEMAN6166
69supercj wrote:Well the JB weld didn't work so I took the M/C back off and ordered a new one. Hopefully it will be of better quality then the rebuilt unit that I had. :x
i really hate when things like that happen.

careful inspection of parts while still in the store is a necessity these days.

Re: Master Cylinder Swap

Posted: August 27, 2014, 10:11 am
by JRANGER
I dunno if this helps but when doing a conversion on my 67 mustang a New Raybestos Dual Bowl Disc Master is used with a proportioning valve to adjust front/rear.

Just curious did the mustang MC directly fit or did you need a bracket? May do this on my truck as its already converted to front disc but its running single bowl stock unit? THat cant be good and i have the dual bowl MC sitting at the house.

Re: Master Cylinder Swap

Posted: August 27, 2014, 10:56 am
by ICEMAN6166
changing to the dual mc is fairly simple
you definitely need one with front discs
you can get a new proportioning valve ,either an adjustable type or a factory one from a truck with front discs.
the pushrod from the single mc is too short for the dual and the one from later trucks with disc brakes is 1" too long so must be cut down.

Re: Master Cylinder Swap

Posted: August 27, 2014, 9:01 pm
by 69supercj
JRANGER wrote:I dunno if this helps but when doing a conversion on my 67 mustang a New Raybestos Dual Bowl Disc Master is used with a proportioning valve to adjust front/rear.

Just curious did the mustang MC directly fit or did you need a bracket? May do this on my truck as its already converted to front disc but its running single bowl stock unit? THat cant be good and i have the dual bowl MC sitting at the house.
The Mustang M/C bolted right up. I do need to make an adjustable push rod as my brake pedal is sitting about a half inch too high.

Re: Master Cylinder Swap

Posted: August 28, 2014, 8:42 am
by JRANGER

Re: Master Cylinder Swap

Posted: August 28, 2014, 4:44 pm
by 69supercj
Thanks for the link but 43 bucks for a pushrod is a bit much in my book. I can make one for the price of a left hand die.

Re: Master Cylinder Swap

Posted: August 28, 2014, 7:17 pm
by ICEMAN6166
69supercj wrote:Thanks for the link but 43 bucks for a pushrod is a bit much in my book. I can make one for the price of a left hand die.
get pushrod from 67-72 non power brake trucks, less than 5 minutes to cut off end and round off.