F19 Cleveland mechancial brakes

[KRW]

Does anyone have information on the go/nogo limits of the brake pads and the wheel hubs? My left brake has no stopping ability at all. From what I can see is everything is working. Pushing the left brake to the stop, I can turn the wheel by hand with no friction.

Keith Willoughby
E-mail [email protected]

[Buell Powell]

Re: F19 Cleveland mechancial brakes

Keith,
Have you tried adjusting the cables?

[KRW]

Re: F19 Cleveland mechancial brakes

Yes I have adjusted the cables. I can manually move the lever to the stop and still no friction.

[lfries]

Re: F19 Cleveland mechancial brakes

I've forwarded your question to a friend who touts the clevelands.
Hopefully he will have some advice/recommendations.

[KRW]

Re: F19 Cleveland mechancial brakes

l Fries:
Thanks for the help. I put a .016 shimm between the pad and the base to see if that would help, but then I could not put the wheel back on. so removed one shoe and now have miminal stopping power. I fly with guys in cubs and super crusiers and they can stop really short so I use the brakes hard and just don't want to switch to hydraulics. My plane came with brakes for both pilot and copilot and putting in two sets of cylinders just doesn't sound fun.

Keith Willoughby
N3560T

[Pearson]

Re: F19 Cleveland mechancial brakes

Keith,

As I understand it, you have adjusted your brakes, you can move the lever but get no friction, and a .016" shim expands the brakes out to where you can't get the wheel on.

I don't know doodly about your specific brakes. I have trouble shot a lot of mechanical problems though. Obviously if someone with specific knowledge of your problem chimes in here, you would want to listen to them. But I noticed it has been four days since the last post regarding your problem. So I thought I would toss out my thinking on the subject and see what you think.

From what you have posted so far, it sounds like your linings are not worn out. My suggestion would be to take the wheel off and have someone activate the brakes while someone else visually checks to see if there is movement down at the wheel. If there is movement of the linings at the wheel, I would try to hold them with your hands or some sort of clamps, clips, safety wire, or something to restrict their movement. Then check to see if there is slop, or play in the linkage up to the brake pedals.

I am thinking that if you are moving the brake pedals, and the brakes are not worn out, that movement is somehow not getting down to where the brakes are. Maybe a cable is off a pully, or a bellcrank is defective, something along those lines.

Always look for the simplest solution. Let us know what you find.

[KRW]

Re: F19 Cleveland mechancial brakes

Richard

Thanks for advise. I am going to work on them some more tomorrow. And will follow your advise. Let you know what I find.

Keith Willoughby
N3560T

[dmcneil]

Re: F19 Cleveland mechancial brakes

Hey Keith,

I've attached a copy of the Cleveland mechanical brake diagram from the Cleveland catalog. It shows everything pretty clearly... with one exception. The exception is the wear plates on the brake shoes. The wear plates are hard steel inserts that are peened onto the wear surface of the shoe where they bear on the actuating lever cam.

I've also attached a photo of a new old stock Cleveland mechanical brake assembly. It shows the hardened wear plates on the ends of the brake shoes and how everything is supposed to be assembled.

There isn't much to these brakes. The operation is pretty straightforward. The lever cam has two flats machined into it which house the ends of the brake shoes. Twist the cam and the brake shoes are pushed into contact with the drum. Wear items are usually the brake linings and the lever cam.

New brake linings are specified at .220" thick although the thickness does vary a little. Besides the brake lining thickness, the other wear factors are drum inside diameter (new spec is 5.4275" ± .0025" i.d.) and, as mentioned above, the operating cam surface slot where the shoes make contact. There isn't any spec on the operating cam. When new, the flats machined into the cam are flat. There is a slight radius on the ends of the cam flats when new. Cams do wear but can be switched from right to left side to use previously unused edges.

The actuating arm shouldn't move very much when the brakes are operated... maybe 1" - 1 1/2" of movement between off and full on.

You might want to rethink your operations with these brakes! Parts are still available from Cleveland but the prices are staggering. It's really nuts. A single brake shoe is listed at $1900!!! That's not a misprint. One brake drum is about the same. Treat those brakes gently! There are used parts out there, too... if you can find someone willing to part with them.

Dan