641 Ford Brake issue

ajhbike · Oct 4, 2021

Tractor left brake can be mashed almost to the floor, so we removed the wheel, the brake cam shaft, and removed the hub. Everything inside looks good and attached correctly.

However, with the hub off we reconnected the cam shaft so we could watch the action of the square end of the cam pivot and spread the brake pads. As the cam turned the bottom brake assembly moved well but the top assembly did not AND the brake pedal would not spring back to its raised position. We put a screwdriver in the assembly and the top assembly was moving like the bottom assembly. The cam shaft had a plus or minus 1/8" up and down movement.

So the top assembly doesn't rotate up, the brake pedal does not spring back up and the and the cam shaft has play in it at the wheel in.

As you can see from the picture, the end of the cam shaft square end fits very well and snugly in between the assemblies.

Can someone point us in the right direction? Thanks. (sorry, duplicated one picture and could not remove it.

Dean · Oct 4, 2021

Steel parts of brake shoes may be worn out.

Most shoes have been relined so many times that the wearing surfaces of steel parts are badly worn. Reliners do not inspect such issues but simply install new linings.

Chinese manufacturers of new shoes use old shoes as models so new shoes are little different.

I have similar issues with brakes on my 64, 4000, even though all brake parts are new.

Do not turn steel drums unless you can find a shop with an old brake drum GRINDER.

Dean

ajhbike · Oct 4, 2021

I understand that there can be some wear on the shoe and liner, but the bottom assembly moves and and the tractor stops although the pedal does not return to the up position. I would like to get the top assembly moving and then address the shoe and liner.

Is there a liner and shoe minimum spec do I can determine the

Dean · Oct 4, 2021

Not that I am aware of.

The brake pedal(s) on most of these tractors do(es) not return fully regardless of springs.

Consider yourself lucky if the brakes function properly.

Dean

pomester · Oct 4, 2021

Lengthen the star adjustment until the brake drags on the drum and then back it off just until it doesn't.

The bottom shoe moves first since there is no return spring on it. Kits come with two springs. The last two brakes I have done have not had the second spring similar to yours. Dunno if that is factory or not. I used two springs when reassembling. It helps with the pedal return. The brakes are capable of working fine with just one spring.

The shoes look fine.

641 Ford Brake issue

ajhbike

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Dean

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ajhbike

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Dean

Well-known Member

pomester

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