Author Topic: Master Cylinder Rebuild????  (Read 4114 times)

camaronut

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Master Cylinder Rebuild????
« on: January 31, 2022, 12:32:17 PM »
I've had my master cylinder re-sleeved by White Post back in 1990....
I used DOT 3 in the beginning, then changed over to DOT5 back in 1995, thinking that it would last w/o absorbing water.

Is it time I should rebuild the master cylinder with new seals?  I didn't know White Post won't honor their lifetime warranty if DOT 5 is used...(makes me wonder why).
Its seems to me that the pedal is going down further than it used to, and I see no leaks......so I'm thinking a rebuild is in order because of the age of the seals???

Thanks...

69Z28-RS

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Re: Master Cylinder Rebuild????
« Reply #1 on: January 31, 2022, 01:38:29 PM »
I had my '69 Corvette Calipers sleeved/rebuilt by LoneStar calipers in 1989, and I rebuilt the MC using std OTS kit, and used DOT 5 in the system at that time, and I haven't had the first issue since.  The car only gets driven a few times a year, but No issues with brakes (and THAT is why I used the DOT 5). 

The only facts different about your car is that you first used Dot3, then changed to Dot 5 (I think that is generally a No no with rubber seals/parts). 

I also had WhitePost rebuild a couple of MC for me over the years ('60 Corvette MC around 1995) and my '69 Z28 MC in 2012; yes WhitePost told me in 2012 not to run Dot 5, but I did it anyway.  Without any info/data as to why I don't follow any/all 'suggestions' I get.. :)   Personally I won't worry about it unless I see a leak, and if I do, I'll buy my own seal kit and rebuild again with Dot5.
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

x66 714

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Re: Master Cylinder Rebuild????
« Reply #2 on: January 31, 2022, 01:46:52 PM »
Mike Gibbons did a master cyl & a meter valve. He too says warrantee void if dot 5 is used. He recommends dot 4. So far so good...Joe
See America's First, Chevrolet

1968 Z/28 Corvette Bronze. Black Hounds Tooth. 02E Los Angeles born 3/13/1968 pnt OO. Purchased March 1976
1969 SS396 Yellow/Yellow 08E Norwood born 8/28/1969 pnt 76E. Purchased April 1981

169INDY

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Re: Master Cylinder Rebuild????
« Reply #3 on: January 31, 2022, 05:33:55 PM »
Camaro Disc Brake Master Cylinder Rebuild Kit, 1967-1969

Order a kit and re-seal it, use good tear down notes and Chassis Service and or overhaul manuals.

Since it had been resleeved  your bores should be fine and no need to replace seats.

DIY it!
Jim
68 SS/RS L35 Th-400 LOS
69 Pace Car L48 Th-350 LOS
68 Z28 M21 LOS

camaronut

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Re: Master Cylinder Rebuild????
« Reply #4 on: February 02, 2022, 02:00:57 PM »
Ordered a kit last night - I'll rebuild it just to make sure....

169INDY

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Re: Master Cylinder Rebuild????
« Reply #5 on: February 02, 2022, 06:11:23 PM »
**Commentary**
Since I have owned my F bodies since the 80's,  I am now finding that it is a continual cycle of repairing things that I once rebuilt or had rebuilt, even garage time and sitting is hard on various systems, Brakes Esp.
Jim
68 SS/RS L35 Th-400 LOS
69 Pace Car L48 Th-350 LOS
68 Z28 M21 LOS

camaronut

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Re: Master Cylinder Rebuild????
« Reply #6 on: February 02, 2022, 07:09:20 PM »
Yeah - I've noticed that my pedal is going down further than it use to - so maybe its time to rebuild.
I totally agree on what you said Indy.......