Broken Pin On Brake Backing Plate

[glcaines]

My M151A2 pulled slightly to the left. I intended to completely rebuild the brakes with new shoes, wheel cylinders, lines, etc. and repack the wheel bearings. Well, I finally got around to it. Since it pulled to the left, I started with the left front wheel. I found the source of the pulling instantly, after removing the drum. The pin at the top of the backing plate that the shoes hook onto, was broken. The button on the front was missing. Since the button on the front of the pin was broken off, both top springs were just laying there, doing nothing. I later found the broken-off button jammed in one end of the bottom spring. I need to replace this pin, but the TM doesn't show this part, so I'm assuming that it wasn't supplied separately from the backing plate. I was hoping that it simply screwed in. If it screws in, I can have a new pin machined if it isn't available. I'm also assuming that I need to replace the entire backing plate. If anyone knows differently, I would appreciate a heads-up and preferably a part number for the pin. I found an NOS backing plate for $50.00 plus shipping. I've attached a photo showing the broken pin.

LF Brakes Broken Pin.jpg

[m75]

Having done a total brake replacement on my A2, I would recommend just replacing the backing plate with a fresh NOS one. Plenty available, and no machining required, or worrying that this repair might not hold. And you should be able to source one for less than the $50.00 mentioned.

[rickf]

That is a pressed in (and possibly welded) part of the backing plate and 50 bucks is cheap for a new one. Best to just go the safe route.

[glcaines]

I went ahead and ordered an NOS backing plate. Hopefully, it will arrive soon. I'm currently in the process of replacing brake shoes, wheel cylinders, seals and hoses and re-packing all bearings on all four wheels. I've finished the left rear - three more to go. The bearings on the left rear were completely dry with what remained of grease hardened like plastic. The bearings, however, appeared to be in good shape. I chose not to replace the sleeves, as they showed zero wear.

[rickf]

It sounds like the bearings on this thing have never been addressed so they really should all be pulled and packed and new seals put in. That way you know it is done most likely for the rest of the time you will own it. If a bearing goes out it will generally take a lot of stuff with it.

[glcaines]

Thanks Rick. I'm repacking all of the bearings and replacing the seals on all wheels. I'm completely finished with the left rear and starting on the right rear. I ran into problems with the right rear. The nut was so tight I had to use a breaker bar to get it loose. The nut wasn't rusty, it was simply way over-tightened. Then, I couldn't get the spindle assembly out. On the left rear, it simply slid right out once the nut was removed. On the right side I had to use a puller to remove it and even with the puller it was difficult and I had to really work hard with the puller. Turns out the splines were very rusty but I couldn't see any rust with it installed. I think I can clean everything up, however. It will be clean and greased when I reassemble it.

[rickf]

This is exactly why I said to do them all! Once you are done you will know they are all correct and you will not have to worry about them for a long time. While you are at it be sure to service the axles and make sure they are cleaned out of all old dried out grease. Nasty jobs but once done with the amount that most of us drive our 151's it will never need to be done again beyond a cursory inspection.