8KCAB Brake Master Cylinder overhaul

[Joe]

Correction- Looking back at Bob's post, his Cleveland 10-54 cylinder did in fact require the stat-o-seal washer. My Gerdes A110-44 did not but the rest of the o-rings were the same. And the Gerdes A110-10 uses completely different sized o-rings.

 

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I ordered two rebuild kits from PlanePartsInc.com but it ends up they're not correct for the Gerdes A110-10 master cylinders. The website showed the Cleveland 10-54 and the Gerdes A110-10 as using the same kit but now that I've received them it appears they are different. The main difference is that the Cleveland uses a Lock-o-seal where it appears the Gerdes just uses an o-ring and that o-ring (Part number MS28775-008 I think) isn't in the kit.

The part numbers for the four o-rings appear to be
MS28775-008
MS28775-111
MS28775-014
MS28775-011

PlanePartsInc.com has already revised their website page to show the kit is only good for the Cleveland 10-54 and not the Gerdes A110-10 also. The current Cleveland parts catalog shows the Cleveland 10-54 was originally manufactured as the Gerdes A110-10 but that isn't correct which has contributed to the parts kits being incorrect. Page 8, Note 1 on the left in the link below.

https://www.aircraftsupply.com/pdf-files/Cleveland-Seal-Repair-Kits.pdf

Also wanted to add that the interior bore of the Gerdes cylinder is a steel sleeve so it'll need a coating of hydraulic oil during reassembly if the cylinder isn't going back into service right away. I'd guess the Cleveland cylinders are also steel lined so take a look and lube it up during reassembly if the parts are going to be sitting for any length of time.

I ordered two rebuild kits from PlanePartsInc.com but it ends up they're not correct for the Gerdes A110-10 master cylinders. The website showed the Cleveland 10-54 and the Gerdes A110-10 as using the same kit but now that I've received them it appears they are different. The main difference is that the Cleveland uses a Lock-o-seal where it appears the Gerdes just uses an o-ring and that o-ring (Part number MS28775-008 I think) isn't in the kit.

The part numbers for the four o-rings appear to be
MS28775-008
MS28775-111
MS28775-014
MS28775-011

PlanePartsInc.com has already revised their website page to show the kit is only good for the Cleveland 10-54 and not the Gerdes A110-10 also. The current Cleveland parts catalog shows the Cleveland 10-54 was originally manufactured as the Gerdes A110-10 but that isn't correct which has contributed to the parts kits being incorrect. Page 8, Note 1 on the left in the link below.

https://www.aircraftsupply.com/pdf-files/Cleveland-Seal-Repair-Kits.pdf

Also wanted to add that the interior bore of the Gerdes cylinder is a steel sleeve so it'll need a coating of hydraulic oil during reassembly if the cylinder isn't going back into service right away. I'd guess the Cleveland cylinders are also steel lined so take a look and lube it up during reassembly if the parts are going to be sitting for any length of time.

I sent you a pm with this same question

My name is Dave Hardin and I have these Gerdes master cylinders on an experimental T18, I ran across your post when researching and I was curious if the orings you listed worked out ok ?

The part numbers for the four o-rings appear to be
MS28775-008
MS28775-111
MS28775-014
MS28775-011

When I measured the orings in my cylinders the above numbers look pretty close, did they work? In particular the -008 and the -011?

Thanks a lot

Dave

 

[Bradc16]

Those are the part numbers I used in my 8KCAB cylinders and no issues after several months of flying. I also have a T-18, but I don’t believe I have Gerdes in that plane.

 

[Bartman]

Dave,

Did you find the A110-10 kit on their website? It was months ago but I think it did work out fine.

 

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Dave,

Did you find the A110-10 kit on their website? It was months ago but I think it did work out fine.

Yes I did find the kit on their website. They have some good kits for out of production assemblies. I was trying to go down the find the orings myself route once I opened it up and found it didn't have the statoseal but used an oring in it's place. That is when I found out that this Gerdes and the Cleveland 10-54 are not exactly the same. Then I stumbled across your post and here we are.

My T18 was wrecked by the previous owner, I am just now getting it close to going back together and thought I would rebuild the brake cylinders while I had them out. It has Gerdes on pilot side and Cessna 541138's on the passenger side. The cessna has a lockoseal and not a statoseal so I am not sure the kit from planeparts will work but I will contact them .

Thanks for the help.