7FC-EC Brakes

[bob turner]

The aircraft has hydraulic brakes. Reminds me of stock Stinson, but I have zero experience with these.

Are they any good? Is there an expander tube in there? Should we convert to Cleveland 30-19s?

[dlrude]

The aircraft has hydraulic brakes. Reminds me of stock Stinson, but I have zero experience with these.

Are they any good? Is there an expander tube in there? Should we convert to Cleveland 30-19s?

Hi Bob,

They probably shoe and drum brakes with a hydraulic cylinder. But that's a guess based on experience.

go to => http://www.parker.com/literature/Aircra ... 001-11.pdf

See page 91.

I assume you own this plane? What makes you unhappy about them such that you consider converting them?

Dave

[bob turner]

I guess I missed this response. I drop in here about once a month, seeking Champ info. I own a Super Decathlon and am very pleased with it, but instruct in Cubs and Champs. The Dec is a lousy taildragger trainer, but a superb airplane.

The airplane above is owned by someone else, and is about to get fitted with Grove brakes. It is used as a trainer, and the brakes that it has are indeed Cleveland hydraulic drum brakes. I can find no authority for them in the type certificate, but I have a maintenance manual that says 7ECs were delivered with them. They are apparently not satisfactory. I am not instructing in this one.

Part of the problem is that the master cylinders are those Cub- like Scott deals, and are not suited for the quantity of fluid needed for the drum brakes. They will work just fine for the Grove setup, since that is what the Cub STC calls for.

The only question now is - are those Scott master cylinders legal, or do we have to get them approved? The logs are no help, and I have not seen the 337s. The thing was legally converted from 7AC to 7EC.

[Paul Agaliotis]

Bob,
The CUB master cylinders were not standard on the Champs. They used a more standard cylinder under the floorboards. The Cleveland wheels are included in the TCDS, item 201(d).
There's nothing wrong with the DHB brakes and actually work pretty good. They don't work on the PA22's because of the crummy master cylinder. Steve's Aircraft has a modification to make these a piston type and removes the diaphragm. The expander tube brakes were designed for the diaphragm master cylinder, they need a high volume of fluid and not as much presure. The Cleveland's need higher presure and little volume.
Paul

[bob turner]

Thanks Paul - we sort of recognized that and are going for a package including the Grove master cylinder. The Grove setup is similar to Steves, but uses a slightly smaller bore and a different style of reservoir valve. I have them field approved on my J-3, and they seem to be bulletproof.

Thanks for the news on the Scott masters. I sort of was guessing that they were an unapproved add-on, but the work was done by the U of Ill aviation department, so we may yet wind up with ancient approval paperwork.

I will post when the DER work is done - this will be a lower cost disc conversion. Cleveland prices are headed for the stratosphere.