Uneven brake lining wear

[53k]

When I had the rear drums off my '64 Daytona convertible I found that the shoes were very thin on one end and full thickness on the other. Any ideas why they have worn so unevenly? The fronts were fine.
Thanks,

[img=right]http://www.frontiernet.net/~thejohnsons/64%20Daytona%20Convertible/Copy%20of%20DaytonaConvert7-20-06.JPG[/img=right]

Paul Johnson
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine

[hank63]

All rear drum brakes I can recall, have had only one brake cylinder per wheel. The brake shoe ends close to the wheel cylinder touch the drum first (when pushed apart by the hydraulics) causing more wear at that end. I cannot recall a single design where the rear brake linings had even wear (manual or auto adjusters).
/H

[CHAMP]

Could be something as simple as brake adjustment or weak brake springs or sticking-corroded wheel cyls. Might also want to check rubber brake hose.

GARY H 2DR.SEDAN 48 STUDEBAKER CHAMPION NORTHEAST MD.

[studegary]

I don't recall if your car has disc or drum on the front. The rear brakes are different for each system. In either case, I think that the brakes were not adjusted properly. If it is the disc (in front) rear set-up, I can really believe that the adjustment was not correct. There are not many Studebaker people that know how to adjust them correctly, and far fewer non-Studebaker people know how to adjust them. Most every Studebaker disc brake car that I have purchased had the rear brakes improperly adjusted. Do it by the shop manual.

Gary L.
Wappinger, NY

1959 DeLuxe pickup (restomod)

[53k]

quote:Originally posted by studegary

I don't recall if your car has disc or drum on the front. The rear brakes are different for each system. In either case, I think that the brakes were not adjusted properly. If it is the disc (in front) rear set-up, I can really believe that the adjustment was not correct. There are not many Studebaker people that know how to adjust them correctly, and far fewer non-Studebaker people know how to adjust them. Most every Studebaker disc brake car that I have purchased had the rear brakes improperly adjusted. Do it by the shop manual.

Gary L.
Wappinger, NY

1959 DeLuxe pickup (restomod)

Thanks Gary. This one is manual drums all around (finned) with star wheel adjusters. I'll break out the manual and see if something was done incorrectly before. I know they have been apart because the star wheels were wrong on one side.

[img=right]http://www.frontiernet.net/~thejohnsons/64%20Daytona%20Convertible/Copy%20of%20DaytonaConvert7-20-06.JPG[/img=right]

Paul Johnson
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine

[N8N]

If they were run for many miles without adjustment, the top of the leading shoe will wear thin before the bottom. Nothing to worry about, just do a standard brake job and things will be fine. I believe a '64 should have self-adjusters, so it would be a good idea to make sure that the adjusting mechanism is assembled working correctly. The star wheels are side-specific on cars with self adjusters, so this may be your problem. Beyond that I don't know; I have very limited experience with them; the only vehicle I've owned with self adjusters was my '67 Dart, and putting that to rights was a simple matter of dropping about $50 at my FLAPS for all new parts.

Also since you're in there, you might as well pull the backing plates off and give them a good inspection. If the car has a lot of miles on it there might be a groove in the pads that the shoes ride on; just grind them bright, build up some MIG weld, and grind them back flat again. Of course you should sandblast (or electrolytically derust; the lazy man's sandblaster) and paint them. Few things are as joyous as working underneath a car where all the parts are cleaned and painted.

nate

--
55 Commander Starlight

http://home.comcast.net/~njnagel

[53k]

quote:Originally posted by 53k

When I had the rear drums off my '64 Daytona convertible I found that the shoes were very thin on one end and full thickness on the other. Any ideas why they have worn so unevenly? The fronts were fine.
Paul Johnson

I guess I am suffering from severe CRS. While I was waiting for my power steering hose for the Wagonaire, I decided to fix my unevenly worn rear brakes on the convertible. So, I pulled the right rear hub/drum. Uh, the lining there was perfect. OK, I have enough linings for one rear brake set. That's good. I won't have to order one. So, I pulled the left rear hub/drum. Uh Oh! It's perfect too. I guess the badly worn linings were on the front. I started to pull a front, but decided it was getting late. So, I'll look at it tomorrow. I'm getting to where I scare myself.

[img=right]http://www.frontiernet.net/~thejohnsons/64%20Daytona%20Convertible/Copy%20of%20DaytonaConvert7-20-06.JPG[/img=right]

Paul Johnson
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine

[John Kirchhoff]

One thing that can cause uneven brake lining wear is if the drums have been ground repeatedly or are very badly worn, which results in the inside diameter of the drum being oversize. The result is that, at least at first with new shoes, only a portion of the lining contacts the drum because of the difference in the arc. Eventually all of the lining will contact the drum, but of course the first part to wear is also the first wear out. In the good old days (before my time) it was common to grind the lining so it would fit the drum from the get go. I also think some would shim the new lining before it was riveted onto the shoe to make it better fit the drum. Hmmm, riveted lining, that's something the younger generation probably hasn't seen before.

From a mechanical standpoint, the front lining is under a greater load and should wear faster, all other factors being equal. When the brakes are applied, the drum has a tendency to "drag" the front shoe with it and since it pivots at the bottom, the shoe is thus forced tighter against the drum. At the same time, friction drags the top of the rear shoe with it which has a tendency to reduce the pressure against the drum. Most old drum braked motorcycles used double leading shoes on front for extra stopping power. For their size, they were suprisingly powerful when going forward. However, if you were rolling backwards, applying the front brake was an exercise in futility since the drum dragged both shoes away from the drum surface. That's why the rear brake was of conventional design and worked equally well (that's a matter of opinion!) no matter which direction the drum was turning. At least the rear brake would stop you when rolling backwards. The problem was needing to have one foot off of the ground to operate the brake pedal while rolling in the wrong direction which makes balancing a bike very much more difficult. I'd almost forgotten how embarrassing it was to dump the bike in front of a crowd while trying to backing to an angle parking spot! Some things are best forgotten!

[53k]

quote:Originally posted by John Kirchhoff
[... Hmmm, riveted lining, that's something the younger generation probably hasn't seen before. ...

Thanks for the thoughts. I hope the drums aren't worn. However, I think I have a few laying around if they are bad. Speaking of riveted linings, when I was going through my parts hoping to come up with a set of shoes/linings for the convertible I found that I must have 50 - 60 NOS Studebaker linings for riveted appilcation.

[img=right]http://www.frontiernet.net/~thejohnsons/64%20Daytona%20Convertible/Copy%20of%20DaytonaConvert7-20-06.JPG[/img=right]

Paul Johnson
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine

[kamzack]

One of the items that is often overlooked is fitting shoe to drum. When installing new shoes on a turned surface, put shoe in the drum and notice if there are any gaps. If there is a gap at either end put shoe on a firm surface with curved or lining up and use a dead blow hammer to spread the shoe slightly to fit the drum. If the shoe has a gap in the middle, stand shoe on end and use hammer to decrease the arc until it fits the drum. We've seen significnet increase in life of shoes and a more even wear pattern. In addition to what's been stated by others, this will be one more tool to increase better braking and life of said components. I would suggest not turning drum unless absolutely necessary. Have them micced before cutting. They are getting harder and harder to find in useable condition.
Hope this helps,
Kim

[53k]

quote:Originally posted by kamzack

One of the items that is often overlooked is fitting shoe to drum. When installing new shoes on a turned surface, put shoe in the drum and notice if there are any gaps. If there is a gap at either end put shoe on a firm surface with curved or lining up and use a dead blow hammer to spread the shoe slightly to fit the drum. If the shoe has a gap in the middle, stand shoe on end and use hammer to decrease the arc until it fits the drum. We've seen significnet increase in life of shoes and a more even wear pattern. In addition to what's been stated by others, this will be one more tool to increase better braking and life of said components. I would suggest not turning drum unless absolutely necessary. Have them micced before cutting. They are getting harder and harder to find in useable condition.
Hope this helps,
Kim

Thanks for the good info.
I'm beginning to really scare myself though. After finding that both rear lining sets were ok, today I pulled the right front wheel. The linings were fine on it too. So, thinking the uneven lining was isolated to the left front, I pulled that wheel. Nothing wrong there either. [?][?] I must have had a REALLY realistic dream. I can't imagine what I was thinking about because I haven't had any other brakes apart for a long time[:I]. One positive thing at least is I properly torqued the rear axle bolts and all the lug nuts (some were way below the recommended torque).


[img=right]http://www.frontiernet.net/~thejohnsons/64%20Daytona%20Convertible/Copy%20of%20DaytonaConvert7-20-06.JPG[/img=right]

Paul Johnson
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine