Silly question about adjusting brake shoes

[darth_linux]

So, on my '66 Newport with 4 wheel drums, after getting the brake booster rebuilt and the pushrod length adjusted, my brakes are a little too sensitive and easy to lock up. I think they are adjusted too close to the drums. I know the FSM says to back the adjuster wheel "10 - 12 clicks" after a "slight drag" is felt in the brakes for "proper adjustment".

Is there some kind of measurement I can do of the diameter of the shoes that gets me close? For example, let's just say if my drum is 11" in diameter and I adjust the shoes to be 10 3/4" across, that's an 1/8" gap from either shoe to the drum itself. Would that work? I know that shoes expand outwards from the bottom and therefore might be more of an eccentric than a perfect circle . . .

I'm just thinking out loud here and trying to avoid the "pokey pokey" of the adjusting lever and counting to 12 with the star-wheel, while on my back under the front suspension. I'd rather remove the drum, do a good visual inspection while sitting on my bum and have some setting that I know will just "work."

Looking forward to your replies!

 

[MONC440]

Usually if they are locking up when you apply the brakes they are adjusted too loose. You can do all the measurments you want but the best way is by feel. Mount the drum and turn the adjuster out until the shoes just drag the drum. Do all 4, apply the brakes a few times and check them to see if they are still dragging just a bit. Or you can do it the way my dad did, make sure the auto adjuster is working and just drive in reverse and apply the brake a few times and the will self adjust.

 

[413]

1/8" gap per shoe is waaaayyyy to much.

Can get it close with drum off but the drum needs to be on and shoes expanded with the brake pedal so they are even inside the drum, then adjustment will be correct.

You brakes were working fine before the booster rebuild, then they were touchy after. The shoe adjustment is not the problem, the booster is. Have you had a discussion with the booster rebuilder about it?

 

[CBODY67]

Brake sensitivity is not really a function of their adjustment, it IS more a function of the lining material, to me. Response of the booster is a common factor in all situations.

Brake adjustment results in pedal height, as to when the braking starts, "at the top" or "mid-push", usually. I like "at the top", myself.

As to the initial adjustment, get a "brake shoe/drum caliper" tool. Puts everything where it needs to be from the start. A simple tool to use. Takes the "guesswork" our of the situation. Then the self-adjusters take it from there.

When was the last time the drums were "cut"? Just curious. In prior times, if drum brakes suddenly got "touchy" after a brake job, it was due to the "a bit not smooth enough" finish on the newly-cut drums, usually.

Perhaps a name-brand brake shoe supplier has a set of "HD" linings for the shoe width on your Newport?

Just some thoughts,
CBODY67

 

[Big_John]

I'm just gonna toss this out there.... Are you sure it's the car and it isn't you not being used to the sensitivity of the old Mopar power brakes?

 

[Big_John]

Mount the drum and turn the adjuster out until the shoes just drag the drum. Do all 4, apply the brakes a few times and check them to see if they are still dragging just a bit.

^This^

 

[darth_linux]

I'm just gonna toss this out there.... Are you sure it's the car and it isn't you not being used to the sensitivity of the old Mopar power brakes?

I’ve been driving this car for nearly 3 years and I had another Newport back in the late 80s, so I think I’m pretty familiar with how sensitive the brakes should be.

 

[darth_linux]

1/8" gap per shoe is waaaayyyy to much.

Can get it close with drum off but the drum needs to be on and shoes expanded with the brake pedal so they are even inside the drum, then adjustment will be correct.

You brakes were working fine before the booster rebuild, then they were touchy after. The shoe adjustment is not the problem, the booster is. Have you had a discussion with the booster rebuilder about it?

The rebuilder is not much for conversation. Initially, I did not know that they had reset the booster pushrod, and it was not adjusted correctly. I brought it out quite a bit, to the witness marks that were there from before it was rebuilt, but I’m not sure it’s exactly right yet. I might adjust it some more before I pull the drums and look at the shoes. Or I might just check the Drums first and then go back and add more preset to the push rod on the booster.

 

[carguy300]

Usually if they are locking up when you apply the brakes they are adjusted too loose. You can do all the measurments you want but the best way is by feel. Mount the drum and turn the adjuster out until the shoes just drag the drum. Do all 4, apply the brakes a few times and check them to see if they are still dragging just a bit. Or you can do it the way my dad did, make sure the auto adjuster is working and just drive in reverse and apply the brake a few times and the will self adjust.

Thats the way we always did it.

 

[GregG48203]

check the Drums

Check to see if the drums and/or the shoes are glazed.