The Stovebolt Site Forums The Shop Area Driveline Laminated (glued) Brake Shoes

I thought I would share an experience I had recently... This past week I was driving my truck in of all things a funeral procession. Just as we neared the cemetery, I stepped on the brake pedal to find a sudden increase in pedal travel and a severe pulsing from the drivers side front. After the service, I limped home on 3 1/2 brakes. Until this, I've had pretty reliable braking. When I took the drum off I was surprised to find that not one, but both brake pads were separated from the shoes and were loose in the drum. No evidence of any rivets holding them to the shoes. The pads were still plenty good, only slightly worn. Luckily the only damage was to the clip that keeps the adjustment from turning on its own on the wheel cylinder. Too bad the only way I seemed to be able to locate one was to get a new wheel cylinder as I couldn't find the old cylinder I thought I had around...

The shoes on the truck were probably from the 70s. When I started driving the truck 20 years ago I went through the brakes and the front pads looked new, so I kept them. I never noticed that they didn't have rivets. The few times I had the drums off for inspection over the years, they still looked good and were well within spec so I kept them. The guy at the brake shop said that those never last more than about a year. He rebuilt mine the right way with rivets. Next chance I get, I'm going through the other brakes to see if any don't have rivets and if they don't, they will be redone.

Anyone else have this experience?

I've installed thousands of brake shoes with "bonded" linings since I started doing brake work in the late 1950's. The guy at the brake shop is as full of "fertilizer" as a Christmas goose. Done properly, bonding brake linings with the right kind of thermo-setting cement is much more effective than riveting, and it allows for considerably longer lining life without the rivets putting gouges in the drums. Occasionally an improperly-bonded lining will separate, or it might be possible for rust to develop between the lining and the brake shoe and break the glue bond on a brake that has sat unused for years.
Jerry

That makes sense, I guess I need to cook a goose. (haven't had one in a while, a little fatty, but plenty tasty) They certainly did last for a long time, I'll chalk it up to age probably being the major factor.

Semis have had bonded linings for about 50 years. I got in on the tail end of riveting them, and the failure rate was pretty high, but thats how it was in those days. There were lots of guys that bolted them and the failure rate was even higher. I would not use brakes that were old because rust causes the bonding to come loose. On our rigs that are in service, I don't remember the last failure we had. I have about a dozen storage trailers, and I can just about count on a brake pad falling off if I try to move them.

Good thread... I've had two sets of bonded linings come apart on the rear brakes of my '93 Toyota 4x4. No problems on my other vehicles so far. ('99 Dodge Durango and '55 Chev pickup)

Come to think of it, I haven't seen a riveted shoe in quite some time, and of course every pad for a disc brake I've seen hasn't had them either, and I'm sure the pad material on them isn't just floating there. It's one of those things I have never given thought to, but as always, there's someone out there who has, or has lived through it. Thanks guys. Age strikes again on a truck that has been in service for nearly 70 years.

The bonding agent used to attach friction material to brake pads and shoes is a "thermo-setting cement". It's a liquid or paste that's applied to the mating parts, which are then clamped together and baked at about 400 degrees F. or so. The glue sets up solid as it's heated. Once it's cured, further heating short of red hot doesn't make it release. When I was stationed on Okinawa, I would watch the local parts rebuilders attach new brake linings onto old brake shoes. The shoes would be heated red hot with a torch, the remains of the old linings would be chiseled off, the shoes were cleaned up on a belt sander, and linings were applied, clamped on, and the assembly got baked in a furnace to bond the new linings. No problems with loss of brake material from those recycled parts! The lining material came on a big roll, and was cut to size to fit specific brake shoes.
Jerry

....same reason Jerry stated, is why I changed the "good" shoes on a vehicle that's been sitting for almost 20 years. No way I'd trust those.
...on the other hand I just changed the brake on a late model Jeep Wrangler (not a rock crawler) where the bonded brake pad came loose. Strange things sometimes happen especially when you consider who makes most of them and if is a Monday or Friday production!!