8KCAB Brake Master Cylinder overhaul

Bradc16

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Sorry about that Bartman, I went through the same process. I did not mention it here because they had already corrected their website. Planeparts Inc. was very good to work with.
 

Bartman

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Yes, Bob from PlanePartsInc.com was very quick to reply and I spoke with him this morning, he's already sent two new kits for the Gerdes A110-10 cylinders via Priority Mail so I'm happy.
 
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Big Ed

N50247 - '79 Super D
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About to start the same project. So if I
have the Gerdes A-110-10, I should order the correct kit from PP LLC, there is no kit available from AS INC, and the Cleveland 10-54 will not work,correct?

I also have a leaking caliper. Do I need anything other than a new O-ring?
 

Bradc16

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That is correct if you want a kit. If you don’t want to order it as a kit you could probably get all of the correct o rings from a parts supplier using the part numbers. The lock nut and snap rings can be reused.
Planeparts was very fast to ship so I would recommend just getting their kit.
I have not had to tackle the caliper yet.
 

Big Ed

N50247 - '79 Super D
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That is correct if you want a kit. If you don’t want to order it as a kit you could probably get all of the correct o rings from a parts supplier using the part numbers. The lock nut and snap rings can be reused.
Planeparts was very fast to ship so I would recommend just getting their kit.
I have not had to tackle the caliper yet.
Thanks, I found the kits on eBay from PP, so I ordered a pair. I ordered caliper o-rings from Spruce. Hopefully I don't need any other caliper parts, as they are crazy expensive.
 

Bob Turner

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The bores can usually be cleaned up with Scotchbrite. I have (a long time ago, beyond any statutes of limitation) used JB Weld in badly pitted bores.

The one thing that seems difficult to fix is chatter. I do not know the pin tolerance that allows chatter, but I had it on one caliper and wound up replacing both pins and torque plate.

Most Champs use the 30-19 caliper. Parts are identical to the one Robbie Grove produces for the J3.
 

Big Ed

N50247 - '79 Super D
Joined
Jul 20, 2020
Messages
938
Location
Tampa, FL
The bores can usually be cleaned up with Scotchbrite. I have (a long time ago, beyond any statutes of limitation) used JB Weld in badly pitted bores.

The one thing that seems difficult to fix is chatter. I do not know the pin tolerance that allows chatter, but I had it on one caliper and wound up replacing both pins and torque plate.

Most Champs use the 30-19 caliper. Parts are identical to the one Robbie Grove produces for the J3.
My torque plates have been bent and straightened at some point in their 45 year history. Cleveland replacements are absurdly expensive. Anyone know of a cheaper alternative?
 

Bob Turner

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I believe, but am not sure, that ACA is using Grove wheels and brakes on new aircraft. Problem is, ACA holds the PMA. I think.
 

Bartman

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About to start the same project. So if I
have the Gerdes A-110-10, I should order the correct kit from PP LLC, there is no kit available from AS INC, and the Cleveland 10-54 will not work,correct?

I also have a leaking caliper. Do I need anything other than a new O-ring?
Bob from PP sent me a kit that is specifically labeled for the Gerdes master cylinder and it included new snap rings and a jamb nut in addition to the o-rings. The service manual covers this rebuild and mentions a teflon seal but I didn't see a seal when I did mine.

Anyone familiar enough to explain where the seal is?
 

Bartman

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Possibly, I've got a spare at the hangar that looks low time so maybe it's never been rebuilt. I'll bring it home and pull it apart later today, will post photos.