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Brake Master Cylinder Return Spring
- Thread starter n981ms
- Start date
My right brake liked to stick. It meant dragging the left brake sometimes to keep the aircraft straight on the ground. Plus, it made using the tow bar a real workout. Many folks use return springs on the master cylinders to mitigate this problem.
So off to the local Ace Hardware store for some Hillman, item #115, 5"x5/8"x0.042" (~3 TPI) springs at $1.15 each (I tried other spring sizes but those worked best). About an hour of my time under the panel and problem was solved.
Right seat pedals.
So off to the local Ace Hardware store for some Hillman, item #115, 5"x5/8"x0.042" (~3 TPI) springs at $1.15 each (I tried other spring sizes but those worked best). About an hour of my time under the panel and problem was solved.
Right seat pedals.
PilotjohnS
Well Known Member
First thing to check is the pivot is a solid rod and not two screws.
I believe this is the set up I have.
Attachments
Eliminating any actual or potential causes for the cylinder to bind is just as easy as putting in the “Tim Taylor fix”……”more power” (OK, more force in this case).
As mentioned above, the causes and fixes are well documented here in past posts.
My Matco cylinders don’t have external springs, and have never bound up. 1400 hours, 11 years. All seals replaced one time (using the Matco kit) at about 1000 hours, 8 years in service. The brakes get used a bit more on an A model than a tail dragger.
As mentioned above, the causes and fixes are well documented here in past posts.
My Matco cylinders don’t have external springs, and have never bound up. 1400 hours, 11 years. All seals replaced one time (using the Matco kit) at about 1000 hours, 8 years in service. The brakes get used a bit more on an A model than a tail dragger.
n981ms
Well Known Member
I should have been more specific. I had no problems through hundreds of hours until recently brake pads and a cylinder were replaced during annual. Therefore I believe there is no misalignment. I will take a closer look though. I did indeed search "brake drag." And have done so again just now. I put a spacer on the caliper and thought I had fixed the problem but it did not. I found numerous references to potentially weak springs in a master cylinder. I know the master cylinder not returning is the problem because when I pull it back manually I have no issues. I will recheck alignment.
Thank you for the responses.
Hmmm....interesting. You might try rebuilding the cylinders with the Matco rebuild kit. It comes with all new seals, new piston, and........new springs. Even though the springs in yours may be OK, the rubber seals do age over time, resulting in the rubber getting hard, and possibly causing the sticking you have encountered.
The rebuild kits are not expensive, and fairly easy to install.
Matco Master Cylinder Rebuild Kits | Aircraft Spruce ®
Matco Master Cylinder Rebuild Kits MATCO Mfg. Master Cylinder Rebuild KitsBuna-n orings are used in the original assembly, these rebuild kits are of same quality.
I rebuilt mine because one of them was just beginning to leak at the piston shaft. It wasn't enough to drip, but that would have come next.
