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Master Cylinder O-rings

G

glenn654

Well Known Member
I have Cleveland master cylinders 10-30 and the o-rings are now leaking because of the 83282 brake fluid and the old nitrile seals. I failed to replace them when I upgraded the caliper o-rings.

I need to replace them with Viton rings but need the correct sizes to order.

Does anyone know off-hand the correct sizes or part numbers?

Will probably order from O-ringUSA


Glenn Wilkinson
 
Master Cylinder O-Ring age

Hey Glenn,

Just curious how old and how many hours you have on your rig with those o-rings and Mil 83282 hydraulic fluid. That stuff is supposed to be completely compatable with systems designed for Mil 5606, as in standard buna-n o-rings.

Nothing wrong with Viton rings, I think that buys you higher temp limits.

I have 365 hours and 4.5 years on my RV-8 with Mil 83282 hydraulic fluid from Royco with stock Cleveland wheel brake calipers and Matco brake cylinders. Haven't seen a drop of red come out of either due to deterierated o-rings or seals. Brakes are good and tight and haven't rebleed them since new. Maybe next annual though. Wonder what gives with your setup. I'm curious to hear the conclusions and outcome since quite a few of us have chosen to use Mil 83282 fluid. Thanks, pal. Let us know. :confused:

Jeff Liebman
RV-8 N139JL
365TT on the Hobbs
Superior IO-360 Hartzell BA Prop
Airglades Airport, FL
 
Glenn,
I have 2-110 & 2-113 listed as the sizes of the older Cleveland style master cylinder O-rings. FYI, no need to upgrade to Viton on the master cylinders or parking brake valve, as these parts do not see slightly higher than ambient air temps [unlike the calipers] Simply replace them with Nitrile O-rings, which can be found almost anywhere. FYI, do NOT use Harbor Freight or any other "Made in China" O-rings. Made in China [I'd avoid anything made in a third world country. Best to buy Made in USA] O-rings are of sub standard quality.
Simply remove your old O-rings and take them to match them up to the replacements.
Charlie
PS The new fluid had nothing to do with the O-ring failure. They simply wore out. The newer fluid is fully compatible with the original Nitrile O-rings. You should be able to source Nitrile O-rings locally from an auto parts store or your local industrial bearing supply house. These days, you never know the quality of small parts like O-rings found at an auto parts store. My experience has been that the bearing supply houses carry good quality stuff.
 
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i just happen to have replaced my caliper oring and took a pick of the package for my last spare oring from aircraft spruce. not the route you are planning but may help others lookn for a spare. i had a spare puck on hand so installed it also at over 4,000 hrs on the original puck. it was a messy job but went quickly. i plugged the brake line after removing the caliper and prefilled the caliper before installing and bleeding from the bottom up.:)
img0649rv.jpg
img0648mt.jpg
 
Upgraded Caliper Piston/Pucks - Parker-Cleveland

I have the new upgraded style caliper pistons with Viton orings as a set for $48. I can email you a pic of what happens to the original design and you'll want to get them out of there. :)

I understand you're looking for Master Cylinder orings... while your messing with brake fluid, this would be a good time to deal with the caliper piston issue to.
 
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Wrong part

Ed,
He's asking about master cylinder O-rings [specifically the older Cleveland units] not caliper O-rings. Vans used to supply Cleveland master cylinders and calipers. They later switched to Matco master cylinders due to cost increases of the Cleveland units. Not sure if they are still using Cleveland calipers on the newest kits?
Charlie
 
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LifeofReiley said:
I have the new upgraded style caliper pistons with Viton orings as a set for $48. I can email you a pic of what happens to the original design and you'll want to get them out of there. :)

I understand you're looking for Master Cylinder orings... while your messing with brake fluid, this would be a good time to deal with the caliper piston issue to.
Click to expand...

Would love to see what the Upgraded style caliper pistons look like.

Can you post both the old and the new upgraded style caliper pistons here?
 
To answer RVJeff et al.

The master cylinders are approximately 20 yrs. old and 344 hrs, I've been flying since '03. I upgraded to 83282 brake fluid about 3 or 4 years ago and thought it was incompatible with the nitrile o-rings and is why I wanted the Viton o-rings. But since that is not the case I can get the replacements more easily.

I guess they were just worn out. Still plyable but outer sides flattened.

Thanks for the info.


Glenn Wilkinson
 
last post was April. any resolve with this issue? I have a 9A that has experience left and right failure, in 2 days. Is there a more dependalbe oring? I'm using o-ring MS28775-218 and oil 5606. Can't afford to have this happen away from home. Oh and the left o-ring replaced 2 months ago, so early failure. (i am new owner)
Thx, DM
 
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