Brake dilema

[oldredford]

Doing a brake job on my 1940 Ford coupe. Dilema, can't get the rear drums on. New shoes and new drums. Drums been turned to make true. Front drums installed. I have taken all the adjustment out of the rear brakes. Shoes won't go inward any more. Help....

[Ken/Alabama]

Have you tried moving the anchor adjustment bolts at the bottom. They center the shoes in the drum. I know the instructions say the dots should face each other but Ive found that sometimes they need to be turned slightly up or down to get the drum on.

[39topless]

Is your emergency brake on?

[oldredford]

Originally Posted by oldredford

Doing a brake job on my 1940 Ford coupe. Dilema, can't get the rear drums on. New shoes and new drums. Drums been turned to make true. Front drums installed. I have taken all the adjustment out of the rear brakes. Shoes won't go inward any more. Help....

I finally got the drums to go on but there is lots of drag. I can hand turn them with lots of effort. Should I drive the car and let the drums and shoes wear in?

[john in illinois]

X 2 39 topless. If your emergency brake was set for old shoes,it could be dragging.

John

[oldredford]

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Originally Posted by john in illinois

X 2 39 topless. If your emergency brake was set for old shoes,it could be dragging.

John

E brake is disconnected...

[19Fordy]

Long ago I know I saw in a tech book how thick the OEM 40 Ford brake linings were.
I think it was .18 in. Can anyone verify this?

[Charlie Stephens]

Originally Posted by oldredford

Doing a brake job on my 1940 Ford coupe. Dilema, can't get the rear drums on. New shoes and new drums. Drums been turned to make true. Front drums installed. I have taken all the adjustment out of the rear brakes. Shoes won't go inward any more. Help....

Did you have the shoes arced to fit the drums? My guess is that you didn't and that your problem.

Charlie Stephens

[Bulligen]

Yes, Pull the drums off and then take the shoes off and set them inside the drums to see how close they match. Is there any residual pressure in the wheel cylinder?

[Karl Wolf]

When properly arced, the shoe should make contact with the drum at the shoe center.
There should be clearance at the ends.
I usually push the end of the shoe against the drum (2" from the end) and look for 1/16"-1/8" clearance at the other end of the shoe.

Karl

[V8COOPMAN]

Originally Posted by Karl Wolf

When properly arced, the shoe should make contact with the drum at the shoe center.
There should be clearance at the ends.
I usually push the end of the shoe against the drum (2" from the end) and look for 1/16"-1/8" clearance at the other end of the shoe.

Karl

Really?

The reason shoes are "arced" in the first place is to remedy the exact phenomenon you describe. DD

[Karl Wolf]

Originally Posted by V8COOPMAN

Really?

The reason shoes are "arced" in the first place is to remedy the exact phenomenon you describe. DD

Really.
When you step on the brakes with a shoe that fits the radius of the drum perfectly, and add force, the shoe bends ever so slightly,the ends of the brake material recieve most of the pressure. As this continues, the center of the brake material does less of the work.

With the first contact being in the center of the shoe, increase in force bends the shoe (ever so slightly) to increase the shoe contact area.

While I've never read this in a book, I got the theory for more than one old guy. (1960's, 1970's) I worked in an automotive machine shop for quite a while. I arced a lot of shoes. Most of the shops I machined drums for sent the shoes to be arced.

Karl

[expavr]

The truck shop that arced the shoes on my tonner cut about 2" off the lining on the rear shoes and tapered the leading and trailing edges of all the linings. When I asked the shop foreman why, he said that the rear shoes provided primary braking force in reverse only and by reducing the lining area on the rear shoes it reduced unneeded friction on the drums which would extend the drums service life. He said the tapers were to prevent the brakes from locking up in a panic stop. Whether or not this might help the "binding" condition you have on your rear drums I can't say, but its something to consider. The attached photo shows the right rear backing plate and shoes on the tonner.

[JSeery]

Originally Posted by Karl Wolf

Really.
When you step on the brakes with a shoe that fits the radius of the drum perfectly, and add force, the shoe bends ever so slightly,the ends of the brake material recieve most of the pressure. As this continues, the center of the brake material does less of the work.

With the first contact being in the center of the shoe, increase in force bends the shoe (ever so slightly) to increase the shoe contact area.

While I've never read this in a book, I got the theory for more than one old guy. (1960's, 1970's) I worked in an automotive machine shop for quite a while. I arced a lot of shoes. Most of the shops I machined drums for sent the shoes to be arced.

Karl

I likewise thought the idea of arcing the shoes was to match the shoe to the drum. Not sure how this gap thing would work, even if it did provide some benefit (which I don't see) it would be very short lived as the material in the center of the shoe would wear away faster than the edges and remove this gap.

[barnfind08]

Just measured some n.o.s. lining O1A-2022 the thickness is .210-.212 till the tapered end which is .150 hope this helps. Of course these are the-kind they rivet on because they are n.o.s

[Karl Wolf]

Originally Posted by JSeery

I likewise thought the idea of arcing the shoes was to match the shoe to the drum. Not sure how this gap thing would work, even if it did provide some benefit (which I don't see) it would be very short lived as the material in the center of the shoe would wear away faster than the edges and remove this gap.

You have point, as the shoe wears in, the contact area increases.

As an addition to this discussion, some where in the early 1970's, Wagner brand brake shoes put forth the notion that they had found a shoe arc that would work with all drum sizes from standard to the maximum oversize, .060 from standard. This made customers come away from the notion that arcing was a necessary practice to be used every time a brake job was done.

I always check the arc.

Karl

[George/Maine]

If you look at post #13 you see that the ends are tapered back. Some times the only arches you will find is mickey ds. The shoes are some times to long and taper makes them shorted. If you measure the end of the shoes most likely they are longer then the id of drum. I was tough to chamfer both ends like a wood chisel.

[cmbrucew]

In the early 1960's I did a lot of brake jobs. I would put the shoe in a vise and file the ends of the shoes toll it laid in the drum nicely. "Shoes arc'ed"
Bruce

[Talkwrench]

IS it oversized linings? hence the need of material to be taken off = arching..
I think this is must be the way you guys do it in the U.S. Here we have first , second, third oversize. Once the drum is measured to determine which one its been machined to, you simply fit that lining, done!

[skidmarks]

The OP said new shoes and new drums. Wasn't there some recent complaints about some of the new brake shoes that are now available?