Re: Master cylinder rebuild
[Re: fastmark]
#2894688
03/02/21 09:26 AM
03/02/21 09:26 AM
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Joined: Jan 2005
Posts: 8,341 Crook County, ILL
Mastershake340
master
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master
Joined: Jan 2005
Posts: 8,341
Crook County, ILL
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67-71 hemi disc did not all use the same master cylinder. 70-71 is different than the earlier years as touched on in this other current thread. https://board.moparts.org/ubbthread...cylinder-any-difference.html#Post2894348They all had 1-1/8” bores, and any MC kit for a Mopar from that era with a 1-1/8” bore can be used to pirate its seals to use to rebuild your master cylinders pistons if your pistons are in good condition to be cleaned up and reused. The kit for 70-71 hemi masters with the 2229191 casting hasn’t been available for many decades so is very hard to find. I did have some primary piston assemblies made up through Raybestos for those a while back if anyone’s looking for one.
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Re: Master cylinder rebuild
[Re: dragon slayer]
#2897792
03/10/21 03:57 PM
03/10/21 03:57 PM
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Joined: Mar 2011
Posts: 3,089 Michigan
A727Tflite
OP
master
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OP
master
Joined: Mar 2011
Posts: 3,089
Michigan
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If you have the MC apart and your pistons are good. Many are not. They can get scuffed, pitted from corrosion mixture between steel, fluid, water, aluminum. You can get seals from the 1 1/8 kit as mentioned.
The MK662 kit works.
For 67-69 B body the MC pistons were set to work with the Bendix 4 piston calipers. 70 B non hemi set for the KH Caliper.
67-70 C body kits also use same seals and some of the pistons same for some B body years.
Post your piston numbers.
I would like one of those primary pistons to get the specs off it, or if you have the design data on length, spring length, etc... Trying to get the forward piston out. Not cooperating. Any tricks ? The bore looks pretty good with the rear piston out. I’m guessing I need long expanding needle nose pliers to grab the piston unless there is a better way.
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Re: Master cylinder rebuild
[Re: sbcjd]
#2897810
03/10/21 04:44 PM
03/10/21 04:44 PM
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Joined: Jan 2005
Posts: 8,341 Crook County, ILL
Mastershake340
master
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master
Joined: Jan 2005
Posts: 8,341
Crook County, ILL
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Are the numbers on the two original pistons 9194 and 6877? Thank you The NOS primary piston in the kit (bagged) is stamped 9194. The kit contains seals to rebuild the secondary piston. The piston above it is a piston I had made by Raybestos to rebuild hemi 9191 master cylinders.
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Re: Master cylinder rebuild
[Re: A727Tflite]
#2897811
03/10/21 04:45 PM
03/10/21 04:45 PM
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Joined: Jan 2005
Posts: 8,341 Crook County, ILL
Mastershake340
master
|
master
Joined: Jan 2005
Posts: 8,341
Crook County, ILL
|
If you have the MC apart and your pistons are good. Many are not. They can get scuffed, pitted from corrosion mixture between steel, fluid, water, aluminum. You can get seals from the 1 1/8 kit as mentioned.
The MK662 kit works.
For 67-69 B body the MC pistons were set to work with the Bendix 4 piston calipers. 70 B non hemi set for the KH Caliper.
67-70 C body kits also use same seals and some of the pistons same for some B body years.
Post your piston numbers.
I would like one of those primary pistons to get the specs off it, or if you have the design data on length, spring length, etc... Trying to get the forward piston out. Not cooperating. Any tricks ? The bore looks pretty good with the rear piston out. I’m guessing I need long expanding needle nose pliers to grab the piston unless there is a better way. I've had luck using compressed air in an outlet to blow pistons out. The commercial rebuilders actually pump grease into the outlet to force the pistons out.
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Re: Master cylinder rebuild
[Re: Mastershake340]
#2897850
03/10/21 06:33 PM
03/10/21 06:33 PM
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Joined: Mar 2011
Posts: 3,089 Michigan
A727Tflite
OP
master
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OP
master
Joined: Mar 2011
Posts: 3,089
Michigan
|
If you have the MC apart and your pistons are good. Many are not. They can get scuffed, pitted from corrosion mixture between steel, fluid, water, aluminum. You can get seals from the 1 1/8 kit as mentioned.
The MK662 kit works.
For 67-69 B body the MC pistons were set to work with the Bendix 4 piston calipers. 70 B non hemi set for the KH Caliper.
67-70 C body kits also use same seals and some of the pistons same for some B body years.
Post your piston numbers.
I would like one of those primary pistons to get the specs off it, or if you have the design data on length, spring length, etc... Trying to get the forward piston out. Not cooperating. Any tricks ? The bore looks pretty good with the rear piston out. I’m guessing I need long expanding needle nose pliers to grab the piston unless there is a better way. I've had luck using compressed air in an outlet to blow pistons out. The commercial rebuilders actually pump grease into the outlet to force the pistons out. Thanks. Thought of that but wasn’t sure if anything else inside would come flying out.
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Re: Master cylinder rebuild
[Re: sbcjd]
#2897918
03/10/21 08:50 PM
03/10/21 08:50 PM
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Joined: Jun 2014
Posts: 1,331 VA
dragon slayer
pro stock
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pro stock
Joined: Jun 2014
Posts: 1,331
VA
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I have had luck with a wooden dowel and tapping with a hammer to compress spring and pop it up. With some lubricant. Rapid tapping. That has worked especially for the first piston. If that second piston is moving but just hanging up AND the lock screw has been removed, the compressed air should get it. Just cover with a towel good. The first time I freed one with compressed air it shot out about 100 feet. Basically an air cannon. Grease also works for those that are really stuck. Yes the 6877 is the secondary piston, which was also in the 69-70 C body Kit and 70 B body non hemi kit.
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