Brakes - NEGLECTED BACKING PLATES

Lee ODell
Lee ODell Senior Contributor
edited November -1 in HUDSON
The brake backing plate wear is often overlooked during a brake inspection or when the brake shoes are replaced. The key areas to inspect are the 6 pads the shoes rest against on the backing plate. There are 2 pads at the top, near the anchor pin, 2 - one on the left and one on the right side, and 2 near the bottom of the backing plate.



The 6 shinny areas on the pads should be inspected at each brake job for excessive wear. Usually, these pads are the same thickness as the backing plate. So, the wear, is an indicator of how much metal thickness is still there.



The 2 bottom pads receive the most wear, next are the left and right ones. And the least wear is at the top 2 bads.



If you see excessive wear patterns, these worn areas of the backing plate pads can repaired. The repairs can be made by wire welding up the groves. Then grind the welds flush with the rest of the pad.



Just so no bearing get welded up I wouldn't connect the welder's ground cable to the axle. I know it sounds like a give, but I've heard its happened. Connect it to the backing plate.



Excessive wear can contribute to uneven brake shoe wear, inside edge to outside edge, because the shoe will not be parallel to the brake drum.



I have seen far too many cars with neglected backing plates, and even some cars where the brake shoes have worn a grove through the backing plate.



A very very thin film (not a thin layer) of white grease or equivilent, on the backing plate pads, will help reduce wear on these pads. Also, this will eliminate a squeek sometimes heard when applying the brakes. The squeek is the metal edge of the brake shoe moving against the backing plate pad. Another way to help reduce wear is to adjust the brakes regularly.



There is a very good close up picture of a backing plate, posted by Dave Kastalic, that will show the shinny areas that should be inspected. There is one shinny area in the picture that is obscured by the parking brake lever.



Dave's post is: "38 112 Covertible Pictures" posted 3-25-10, at 8:30. Picture #2.



Dave's picture inspired me to share with you an often overlooked area of a good brake job. Thanks Dave for the good pictures.



Have a good day. Lee

Comments

  • [Deleted User]
    [Deleted User]
    Lee,



    Thanks for sharing that info! I can't speak for other folks, but the points you made are things that I wouldn't have thought to look for. Mounting the M/C and plumbing the new brake lines are next on the the list for the '39, so I will check the backing plates closely before I bleed the brakes, especially since the front backing plates came from another vehicle(Hornet). The drums and wheels are on the car so that the frame can be rolled in and out of the garage as needed.



    Thanks,



    Kevin C.
  • Lee ODell
    Lee ODell Senior Contributor
    Kevin,



    Thanks for the kind words. Keep us posted on the progress of your car.



    Lee
  • barrysweet52
    barrysweet52 Expert Adviser
    While on the subject of brakes, the master cylinder and brake lines on my 37 Terra are very close to the exhaust pipe. Ive wrapped some lagging around the pipe near the fuel pump to stop vapourisation. Was thinking of wrapping more of the pipe near the brake MC & lines. Something to think about if you are working on your brakes. Regards, Barry
  • [Deleted User]
    [Deleted User]
    Thank you for your comments guys. They are always appreciated as we move along with this restoration.
  • Lee ODell
    Lee ODell Senior Contributor
    Barry,



    How close is the exhaust? Is there room to instal a heat shield?



    Here is another suggestion.



    I've found heat shields to be very effective. One time I used an old shinny stainless steel mud flap, I had lying around the shop, to make a heat shield to protect a customers suspension rubber bushing from a catalitic coverter, that was less than 1/2" away. Prior to that, he was having to replace the bushing every 4 to 6 months. Solved his problem. A cat is alot hotter than any exhaust pipe. Newer cars have been using heat shields for decades. For even more protection on my cars, I have added ducting for cooler air to get between the heat shield and whatever I thought could use the extra cooling. Probably overkill but I do it anyway.



    A heat shield will work to protect a master cyl, brake lines, gas tank, or whatever.



    Now I shy away from wrapping exhaust pipes anymore, after having my headers rust out because of condensation between the wrapping and the pipes. A friends new motor home exhaust had to be replaced, on a 1200 mile trip, because the wrapped exhaust pipe deteriorated. He said it crumbled when unrapped.



    Just sharing some person experiences.



    Have a good day, Lee
  • barrysweet52
    barrysweet52 Expert Adviser
    From memory the engine exhaust pipe is 2 or 3 " from the master cyl, and about 2" from the brake line near the gearbox. Ive heard of possible condensation/rust as a result of the wrapping. Our climate here is drier - Ive never seen snow - so the rust may not be a problem. A few years ago I took my Terra in to an exhaust place and they put it on the hoist and made me 3 exhaust pipes. A week later another Terra owner not knowing went to the same place and asked if they were able to make him a new exhaust pipe. They told him yes they can, they made 3 only last week. Im sure it will be many years before they make any more. Regards, Barry
  • Lee ODell
    Lee ODell Senior Contributor
    I'm glad I asked how close, because I was imagining less than one inch air gap. 2 - 3 inches is a pretty good air gap. I do not think a heat shield would be necessary, but if you are like me why not. I like any idea that will protect the brake system. A little peace of mind is a good thing. And it will make good conversation when someone sees it.



    Lee
  • Geoff
    Geoff Senior Contributor
    barrysweet52 wrote:
    While on the subject of brakes, the master cylinder and brake lines on my 37 Terra are very close to the exhaust pipe. Ive wrapped some lagging around the pipe near the fuel pump to stop vapourisation. Was thinking of wrapping more of the pipe near the brake MC & lines. Something to think about if you are working on your brakes. Regards, Barry



    Remember these guys have the brakes on the right side, which is the LEFT! So they might wonder what your are on about Barry. Our r.h.d. cars present a whole new series of problems when it comes to positioning of pedals, brake cylinders, etc.
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