Left drum locks up first adjustment?

[john.thompson068]

Okay, while testing out my brakes by doing panick stops in an industrial park, I can see that my left rear drum brake is locking up before my right rear drum brake. I think this is as simple as adjusting the star wheel correct. Please save me some time and trouble if you can and refresh my memory before I get around to working on this. Mainly, it is a starwheel adjustment correct? I just rotate the star wheel through the slot in the back plate of the drum? And which way should I turn it to decrease the braking power of that brake?

BTW, car is a 66 Satellite with stock drums on the rear, 10.5" 76 Aspen brakes on the front, a Master Power manual dual reservoir master cylinder and non adjustable proportioning valve, and a Stewart Lock Resistance Brake System (LBS) module plumbed into the rear brakes. The brakes work really good, but I have been thinking power brakes are the way to go in the future.

 

[YY1]

Hmm, never heard of LBS. Sounds like it might be not working as you use the term lock up in your second sentance. Might be part of the problem.

You should only be able to turn the star wheel one way without putting a second screwdriver in to hold the ratchet pawl away.

Please post pics of your car

 

[john.thompson068]

Hmm, never heard of LBS. Sounds like it might be not working as you use the term lock up in your second sentance. Might be part of the problem.

You should only be able to turn the star wheel one way without putting a second screwdriver in to hold the ratchet pawl away.

Please post pics of your car

Here is a link to the LBS.

http://http://www.73-87.com/7387garage/chassis_suspension/lbs.htm

I was actually thinking about taking some pictures soon and posting them in the introduction chatroom or whereever they are suppossed to go. I could do that tomorrow. Anyway, if I remember correctly, the starwheel spreads the shoes apart so maybe I can adjust the brake on that one side to grab less. All the LBS does is prevent the wheels from locking up suddendly by being shocked with brake line pressure from a panick stop, but I can still skid the car if I push hard enough on the petal.

 

[67 coronet]

sounds like an adjustment problem.you should only be able to make your brakes tighter through the backing plate.if you want to loosen them then drum removal will make that a ton easyer.also might check for leaking wheel seal,will often cause the problem you have.might not be a bad idea to pull both drums just to take a look inside and check for any problems.

 

[MarPar]

sounds like an adjustment problem.you should only be able to make your brakes tighter through the backing plate.if you want to loosen them then drum removal will make that a ton easyer.also might check for leaking wheel seal,will often cause the problem you have.might not be a bad idea to pull both drums just to take a look inside and check for any problems.

x2

 

[john.thompson068]

x2

Just had both axles out recently to replace center chunk gasket. Although I do not use a metal gasket on the inner side of the backing plate because I do not want to have to completely remove the backing plate and then have to bleed the brakes, I have never noticed any leakage. Everything was looking good and I did not notice any leaking differential fluid. Certainly none is contaminating the drums or shoes. Looks like I will just tighten down the right side since the skid mark from the left side is fine. I don't want the clutches in the sure-grip to take on wear from having one tire turning while the other is locked.

 

[john.thompson068]

I am about to pull both drums and take a look. I will post some pictures. I am going to mainly check that the shoes are installed the same on both sides and the the primary and secondary shoes are not reversed. I will also check out the starwheel and figure out which way does what. Then readjust the brakes. Later, I can take it out to the industrial park for some fine tuning.

 

[dave5237]

Hello. I answered a post similiar to this. When I first got my car it had 11 inch drums and when I would apply the brakes coming to a stop sign they would grad and lockup. Found out they were warped bad and when my shoe would get close to the drum it would hit this out of roundness I am talking about. After turning both drums worked just fine. 11 inch drums warp easy because thats a lot of surface when stopping especially if your going 70 mph and slamm them on.

 

[john.thompson068]

I took both drums off. There was slight leakage from one of the axle flanges, but this was because I hadn't tightened the nuts quite enough. So I tightened them up slightly. However, there was barely any leakage, and was not affecting the brakes or anything. The top picture shows how clean the side was that was tightened properly. The second picture shows the general condition of both brakes.

Notice how the longer shoe is on the rear? I don't know if it makes a difference but I installed them the same way on both sides.

Pictures three and four show the shoes are looking a little thin and both sides have the same types of cracks in both spots.

Pictures five and six are of the drums. Notice how one of the drums has a weight? I need to know why one of the drums has this weight.

The last picture shows the Stewart LBS valve I mentioned in an earlier post here and gave a link to an article on it.

From the back, when you rotate the star wheel down, it expands the shoes. I had to spin my star wheel quite a bit before the shoes were getting close to the drum again. I adjusted them as follows. I turned the star wheel until I could no longer slip the drum over the shoes. Then I backed off the star wheel just enough to be able to slip the drum back over the shoes. Now when I go test my brakes, I will simply rotate the star wheel down on the one side until both brakes lock at the same time.

Please get back to me on the condition of my brake pads, whether it makes a difference to have the longer lining on the front or on the rear, that one weight, and how I know when I need to replace my shoes. Later I will post the results of my brake testing. Thanks.

 

[Slantsixdan]

Some years ago I saw a rigorous test -- wish I could remember where -- of several of those aftermarket "lock resistance" add-on brake gadgets. Results were longer stopping distance and less predictable braking behavior. I'd get it out of there if I were you.

Instead, I'd reduce the tendency towards rear lockup the way the factory did on cop-spec cars: with smaller-bore rear wheel cylinders. Everyone griped about rear lockup under hard braking in road tests of the time. Consumer Reports wailed about it. Chrysler did nothing about it, which is dumb because the zero-dollar fix was right on their shelves, see here (and TSB here and MTSC info here). 10", and 11", and 12" drum brake wheel cylinders are interchangeable. I routinely swap the 13/16"-bore rear wheel cylinders onto 10" rear drums on cars with 8¼" and 8¾" rear axles, and the ¾"-bore rear wheel cylinders onto 10" rear drums on cars with 7¼" rear axles, and it fixes the problem all the way fixed without having to jack around with an adjustable proportioning valve or otherwise re-engineer the system.

¾" rear wheel cylinder is NAPA 37863 or Raybestos WC-37863 or Bendix
34076 or Wagner WC123412 or Centric 134.67015 or Chrysler 4423 852.

13/16" rear wheel cylinder is NAPA 37696, Raybestos WC37696, Wagner F113704, ACDelco 18E268, Bendix 34064, Chrysler 4313 493, or Centric 134.67013.