Reproduction Parts for 1916-1964 Chevrolet Passenger Cars & 1918-1987 Chevrolet & GMC Trucks


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#470962 06/16/22 11:33 AM
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1941 Chevy Master Deluxe original drum setup

This is only happening on the front driver side wheel. After putting the car away in the garage the brake sometimes will lock and I cannot push the car to roll it in the garage. Now it will instantly let go as soon as I back it out of the garage under its own power. On the test drive it brakes straight, only went 5 miles at 30 mph but tested the brakes a few times. It does this when we have rolled it into the driveway to work on it outside also. It is intermittent.

We have done nothing to the brakes other than inspect them. I believe they were done at some point by the prior owner. The rubber lines are new to the wheels, one has a tag on it. The hardware in the drum looks to clean to have been used. I do not have any records on it but from observation it looks like the brakes were don while the car was parked or just prior to it.

My oldest says he thinks it may just sit to long between uses. Sounds logical but is it really that simple? Is the fix really drive it out of the garage rather than push it 10 feet?


I have found that having an old car is a constant project that is never done. I think that is a good thing. Keeps me learning new things. Having two from different eras is just a form of higher education.
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My '39 used to do that. I would sand the linings and drum and was good for another year.


Gene Schneider
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I expect that will go away after you drive the car a couple of hundred miles. My thinking is that the curvature of the shoes and the drum do not match. So the shoes tend to "wedge" against the drum. Driving will help make them match better.

I agree that sanding the shoes and drum might help. Make sure you bevel the upper and lower edges of the shoes.

The other point to check is make sure the adjustment is correct. You should not have any rubbing when the wheel is rotated. If the drum is out-of-round the shoes could be catching on the high spot.


Rusty

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Originally Posted by Rusty 37 Master
The other point to check is make sure the adjustment is correct. You should not have any rubbing when the wheel is rotated. If the drum is out-of-round the shoes could be catching on the high spot.

I followed the procedure in the service manual for adjusting the brakes. If I remember right is was move X number of clicks clockwise and then back off 4. The wheels turn freely without catching. There is a ever so slight drag but it is even and the same on all of the wheels. If I spin the tire it continues to roll.


I have found that having an old car is a constant project that is never done. I think that is a good thing. Keeps me learning new things. Having two from different eras is just a form of higher education.
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Thanks for that confirmation.

If the shoes are fairly new they are sized to fit a new drum. So in effect they are “undersize”.That means there will be uneven contact when they are applied. Typically the top of the shoes contact the drum first. So that “edge” tends to grab until it is worn some.


Rusty

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Check the shoes for signs brake fluid having saturated the shoes. A leaking wheel cylinder will be the culprit.

I had this same problem when I recently did the MC and WCs. Now there is no sticking but there is a lack of good braking. I didn't change shoes but should have.

Right now I'm counting on the shoes to soon dry out enough to get around town without running over something.

I've installed a concrete block on the rear bumper and run a a rope from it to the real axle. I ran a wire rope to the dash in order to activate this drag apparatus. In case of an emergency that dictates a need more braking power, I can speedily release the block and brace myself against the steering wheel. You know. Agrin

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Charlie dance

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Charlie eluded to a possible problem, if the wheel cylinder has leaked previously the linings may have soaked some brake fluid. I have not had any success at completely removing oil or brake fluid out of the linings other than replacement. This dampness can cause the issue you are describing.
Tony


1938 1/2 ton Hope to drive it before I retire
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Update on the brake. Have driven 3 trips of about 5 miles each. Now the brake is not locking at all. While driving the brakes stop decently considering their design. Fastest I have drives is 40mph, I try to keep it at 30.

If the car is left in neutral leaning on it is now enough to get it rolling. Any incline at all and it will roll.


I have found that having an old car is a constant project that is never done. I think that is a good thing. Keeps me learning new things. Having two from different eras is just a form of higher education.
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Keep a close eye on the wheel cylinders as you drive the car more.

If you search older posts about these brakes you will learn that the pistons (aluminum) tend to bond to the bore of the wheel cylinder. This happens when the car sits for a very long time due to the moisture in the brake fluid and air. There is galvanic action between the piston and cylinder bore.

Remember that the bore will start to rust internally due to moisture in the brake fluid. The bore will also start to rust outboard of the seal and piston due to moisture in the air. The adjusters on the end of the cylinder do not seal the portion of the cylinder bore between the adjuster and the brake cylinder seal.

Now that you are driving the car and using the brakes you are moving the pistons and seals. Unless you have honed the wheel cylinders and installed new seals you could be running the seals over corrosion and pits. These will cut the seal and the cylinder will start leaking.


Rusty

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I am currently in that 'check what is leaking and about to fall off' stage. Since it just received plates after and prior to every drive it will get a good checking. I suspect there will be seals that fail and things that come loose. It sat in a barn at lease 7 years prior to us buying it. Then we worked on it for 4 with a few runs in the driveway.


I have found that having an old car is a constant project that is never done. I think that is a good thing. Keeps me learning new things. Having two from different eras is just a form of higher education.
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My 38 did that. Trouble was that it grabbed the carpet on the floor and threw my wife off her feet onto the compressor. She doesn't like the 38 and that didn't help matters. So I went to the brake people who said it's most probably because it's been sitting, Covid and all and that it wouldn't happen again. That wouldn't satisfy my wife so I told her that I had booked it in for a day to be checked out. I told her that they had gone right over it and fixed the problem which pleased her.


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