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Cleveland brake cylinders

MarkCFI

Active Member
My RV-4 has some slight weeping of brake fluid from the bottom of the master cylinders. I took a look and they are Cleveland 10-30 cylinders. Picture attached.

It looks like the rebuild kit is about $40 dollars each.

Would I be better off just replacing them with Matco cylinders instead of rebuilding? It’s a bit more money but I’m not sure just how easy the rebuild of the 10-30 cylinders is. Several comments on aircraft spruce mention special grease and fabrication of a special tool.

Thoughts?
 

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I have rebuilt the matcos and the clevelands. They are almost identical. Quite easy to rebuild if you have mechanical skills. Takes about 30 minutes and no special tools except snap ring pliers. Check main shaft for scoring and use 600 grit paper to polish. Deeper scratches may require you to start at a lower grit and work up to 600. No grease required, but be sure to lube all o rings with brake fluid before re-assmbly

Larry
 
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Easy fix..and flip them over.

They can be re-sealed/re-built for super cheap and very easy. You actually have them in upside down, which some folks did to purportedly make bleeding easier. If they are flipped with rod upward, there is less fluid trying to escape when sitting around. Also, you can see when the seals are starting to go, as the top gets wet around the circlip. I've attached a very old picture of mine before I switched to the SS lines. Bleed them from the bottom up by pushing the fluid from the bleeder to the reservoir. Likely the shaft seal is all that's leaking on yours (small internal O-ring).
 

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Documentation and advice much appreciated.

I guess I’ll take a run at rebuilding them. I’ve got a bit of time right now.

Thanks again,
 
Have done numerous Cleveland brake cylinders and have done a few Matco ones. The Cleveland ones are easier to do. Only special tool is "snap ring pliers."

In the past, it has been a LOT less expensive to replace the Cleveland O-Rings using the Mil Spec part number than to buy the Cleveland kit.

I find purchasing the Matco rebuild kit the best way to rebuild the Matco brake cylinders.
 
Cleveland 10-30 individual o-rings are MS28775-110 and MS@8775-113

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my cylinders too

Interesting timing. I was just looking at my cylinders today and on line tonight researching kits. Mine are Cleveland 10-20's. (1985 RV-4 kit) I noted that the cylinder kit that Van's sells is for 10-30's and A/S lists too different kits and prices for a 10-20 vs 10-30. I could not see a kit on Van's for a 10-20 cylinder. So be sure you order the correct one.

Mine are weeping at the top (mounted with rod up)
 
I think there are three Different O-rings sizes? Do you happen to know the third?

According to the parts list, if you have a 3rd o-ring it would be a -112 see below. It has been a long time since I rebuilt mine and I only recall 2 o-rings and that is what my pictures show. Just order all 3 just in case.

Screenshot 2023-02-01 at 8.16.30 AM.png
 
According to the parts list, if you have a 3rd o-ring it would be a -112 see below. It has been a long time since I rebuilt mine and I only recall 2 o-rings and that is what my pictures show. Just order all 3 just in case.

View attachment 37727

I believe the third o-ring is #9 in the diagram on the PDF instructions, and the parts list does not show an MS equivalent. It is the tiny o-ring shown in the center of the last picture you posted. While the other two o-rings are inexpensive (<$1.00) that tiny o-ring is part number 101-00100 and ACS has it for $24.90. :eek:

The $40 rebuild kit includes that o-ring.
 
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The brake cylinder geometry is poor on the RV brake pedal design and it puts a side load on the shaft. This wears the shaft and seal over time.
I had a long discussion about this with Matco a few years ago.
So, I just consider it a maintenance item
and a rebuild will be needed every so often.
 
"O" rings made of expensium.....

I believe the third o-ring is #9 in the diagram on the PDF instructions, and the parts list does not show an MS equivalent. It is the tiny o-ring shown in the center of the last picture you posted. While the other two o-rings are inexpensive (<$1.00) that tiny o-ring is part number 101-00100 and ACS has it for $24.90. :eek:The $40 rebuild kit includes that o-ring.

Ridiculous! :mad:

Headed down to JAX Hardware to look at "O" rings.....:cool:
 
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