Drum Brakes

[Damon23]

I'm having a issue with the brakes on the '63 Catalina. They are power drums all the way around. Bringing it home from the shop the car seemed to stop pretty good for drums but after about 10 miles they squealed like mad and the car even wanted to pull to the right a little. I figured the car needed brakes so I ordered a new kit and got to it today. Upon pulling the passenger side front wheel off the shoes look new. The springs not so much but the wheel cylinder looks newer as well. Even stamped made in the usa. One thing I noticed is the shoes don't have wear all the way around. Just at the top of the front and rear shoe. Seems to me their should be wear evenly on the shoe. The drum looks good. No deep grooves or pitting. Could this be a adjustment issue?

[chevybuytroy]

Maybe your wheel cylinder is not compressing the shoes enough to actually be working the way they should?

[redneckjoe69]

i agree.

might also check out the brake lines. some go bad on the inside resulting in no pressure to the wheel cylinder.

[Damon23]

It was not a violent pull just a slight and it only did it once I got down the road about 10 miles. Hoses are easy and available. I've read about the glued brake shoes and the riveted brakes shoes and something about the compounds causing the squealing noise. I'm more concerned about that than the slight pull. When I get back from Daytona next week I'm going to try adjusting them. I've heard different things about that as well. Adjust them until the wheel won't move and then back off a few clicks until they move again is what I remember.

[redneckjoe69]

im just a shadetree. with a decent drum, after bleeding, i adjust til the drum slides on and off with not much resistance.

having had a 71 malibu with 4-wheel drums, and having brake issues,...look into a front disk conversion kit. save your old stuff in case you want to sell one day and the buyer wants it. theres a reason 4-wheel drums havent been used in forever. not worth losing your ride over. not trying to be a d........

do you have any shinny marks on the inside of the drum? or any wear somewhere?

[STINEY]

With drums brakes it is important to get the shoes adjusted close to the drum so there is just a little drag, then mash on the brake pedal to center the shoes in the drum. After this you go back and adjust so there is a little drag again.

There is usually a pretty fair amount of adjustment to be had after the mashing. Makes a big difference.

[silver_bullet]

was taught back in the day that the automatic adjusters only work in reverse... the shop instructors would take the cars out to the nearest empty parking lot, get it rolling at about 15-20 in reverse and then dynamite the brakes... they would repeat this a couple of times then test drive it to see how they did...

[Deaf Bob]

Unless you have dual wheel cylinders (Land Cruiser for one) it wears on part of the shoe.. The worst wear is on the cylinder side.. as the pivot is on the non cylinder side

[yellomalibu]

I haven't done much with drum brakes in a while, but I know if you turn them past spec, they WILL blow out the seals in your wheel cylinders when the shoes wear a little bit. This causes a phenomenon know as "no brakes". Learned that one the hard way.

Old timers used to talk about "dressing" the brake shoes. At least I think that's the term I heard once when it was explained to me. If you can look at or imagine a circle inside a circle, if the arc or curve on the brake shoe isn't the same as the arc or curve of the drum, the shoe will only touch in one spot if the curve is that of a smaller circle or in two spots if it is the curve is that of a larger circle... some of the old timers used to re-curve the brake shoes to match the curve of the drum.
-otherwise, they will eventually wear into each other, but until then, getting even braking will be sketchy.

[Damon23]

I was told about arching the shoes as well. I also was told that I needed organic pads cause the others will squeal like crazy. One thing I did do is adjust them. I put the drums back on and did a couple quick hard stops pulling into the garage and I actually heard the clicking of the adjusters. I'll take it out this weekend and cruise it around and see if I accomplished anything. I may replace the shoes anyway cause the kit I got came with the organic shoes. I'll go ahead and swap out the springs while I'm at it since I have them already.

[Huskinhano]

Yep, Yellowmalibu has it right. Years ago shops would have a brake lathe that would have a sanding spindle, the shoe would be placed into a fixture to grind the lining to the arc of the drum. Linings back then would also be asbestosis compound that worked much better then the linings today. Riveted shoes work better then glued shoes. The glue insulates the lining from everything else and doesn't conduct the heat away, rivets do. Make sure the backing plates don't have groves worn into them where the shoes make contact. I had to weld the backing plates up on my 66 Mustang.My 4 wheel drums worked great. Many times drums had coil springs around them to absorb vibration to keep them from squealing.

Drums can work very well. They'll stop just as well as discs, once! An old trick to make drum brakes work better is to radially drill the drums to displace water and cool better. http://www.tffn.net/drilldrum.html

[G-Motive]

Years ago shops would have a brake lathe that would have a sanding spindle, the shoe would be placed into a fixture to grind the lining to the arc of the drum.

I used one when I worked at the MTA. The shoes came extra thick and had to be cut to fit the drum.

[G-Motive]

If I remember correctly the machine turned the drums and the shoes at the same time. I didn't work there very long and this is way back.

[anotheridiot]

sounds like adjustment. if the drum slides off easily they need to be adjusted if you didnt see fluid in the drum they are not leaking. That dynamite the brakes line though, never should have been taught that way, its pumping the brakes in reverse that self adjusts the brakes. The only thing that helps that along is making sure you have taken the adjuster apart, cleaned it and regreased it so it moves easily, but for the most part, its just removing the drum, lifting the adjuster arm off with a screw driver and turning it so it spreads the bottom of the pads out.

[tardis454]

I'd check all the rubber parts.
Hoses are cheap and wheels cylinders are easy to rebuild as long as cup and spring kits are available.
Check out this video, it shows you how shoe arcing is done..