Brake backing plate post problems (aka bbppp)

[wrighthm]

So I finally got around to fixing my sticky rear brakes on my rover (62 88) and after barely digging into the right rear I noticed the pivot post on the backing plate ( post at the 6 o'clock position opposite the wheel cylinder on the backing plate) was not only free from the backing plate but it is also easily moved around left to right, up and down. I will be cleaning the post tomorrow as it is not big enough to allow my new shoes to simply set into place ( mintex shoes) in the groove of the post. I will be taking a grinder to the end of each shoe and also a steel wire wheel to the post in order for the parts to fit together. Since the shoes would barely fit into the groove out of the box I was unable to fit my new drum over the shoes (clearance issues of course). I hate my truck right now, I mean I really have been bummed for the past 8 months with this thing driving like crap and nothing ever working out, no matter the amount of money I throw at it. I would like to know if someone could help with how to fix the post and backing plate together. Ike at pangolin said it was an easy fix to just tack weld it, but I would like to know how to make sure I tack weld the post in the correct spot since it is freely moving in each direction almost a quarter inch. My solution was to fix the issue with the shoes being too thick to fit in the post groove and then assemble the drum and press the brakes and hope the shoes would be centered since they would be pushing against the drum surface and at that point weld the post and the backing plate together from the outside.

I have been really motivated reading everyone elses threads and posts about brake issues, so thanks to everyone and any additional help would be great. I hope I can have this issue sorted by the weeks end and post pictures of my truck in the Show us your series section finally as a proud series owner

[cedryck]

backing plate peg

That peg should be pretty stationery. Should not move as it is intended to orientate shoes as they move, to braking and recessed position. Seems like a small shot of weld would be a quick and effective solution. I am not sure how they are held on originally, I think maybe press fit or peeenned over to make it stable. But regardless, you want it stable.
cheers.
Jeffrey

[wrighthm]

A little update; I took a grinder to my new mintex shoes today and slowly worked them until they fit on the post. I managed to get everything back together and then I tested my brake pedal only to find it was really sticky. One pump was necessary then you would get a super sticky pedal that would not return after pressure was released from it. I had my girlfriend press the brakes as I turned the wheel and I found as she pressed it down it took almost a full five seconds for the wheel cylinders to respond. The brakes came on as she let off the pedal and several seconds later the brakes would let free. Anyone know what the cause is and maybe how to fix this or avoid it in the future?

[cedryck]

might try purging any old fluid with a pressure bleeder, good place to begin,
how is the condition of master and wheel cylinders?

[jac04]

Sounds like you may have bad flex hoses and possibly air in the system. The flex hoses will swell and close off the fluid passage resulting in the symptoms you describe.

You have an excellent idea for locating the pivots before welding them in place, but (IMO) you should not be grinding on the new shoes. Something is wrong if you have to, and it would seem unlikely that the shoes are too thick.

[wrighthm]

The entire braking system is new. All wheel cylinders, master cylinder, hard lines and flex lines. The last old things on my brakes were the rear drums and shoes. I even bought a set of four adjusters. The only thing left untouched were all four backing plates.

Jac - i was only grinding the shoes where they touch the pivot post. It was like they were too thick or rather that the post had a little crud caked on it from years of being on the road and the crud had made the groove that the shoes fit into smaller. The amount taken off was less than what I could measure with a tape. Sorry for being non specific on what part of the shoes were being ground down.

I tried cleaning the post to free up the extra room needed for the shoes not to be stuck in place and I had a hard time accessing it so I went at the shoes instead.

Last thing, the brake pedal and system worked well ( except for sticking in the rear) before I changed the shoes and drums. After the work was done was when the pedal got sloppy and would not return as it should. I did not rubber band the pistons of the wheel cylinder while shoes were off. The rubber dust boots kept them in place good enough for me not to worry that they would come out. I was thinking that the pistons moved in and out of the cylinder as I cursed and attempted to get the brakes back together with the new components, and that the fluid was compromised with air when the pistons moved and the pedal was not pressed? Hopefully all I need is to bleed the brakes. It really helps me a lot hearing everyones opinions, thanks!

[tmckeon88]

I had that exact same problem plaguing my brake system for many years before I finally tracked it down. (Actually Robison Service in Springfield, MA did, to give due credit.) They tack welded that loose post in place and I was at last able to bleed and adjust the brakes to have a firm pedal. That worked OK for about a year then the tack weld let go, and I was back to double-pumping the brakes again. This summer when I did a replacement of the brake shoes I actually got a new backing plate and replaced the old one altogether. (I think it came from Rovah Farm in Maine; I'm not sure RN has them.) The system works very well now and I can recommend replacing the plate because a tack weld will surely work its way loose over time. The bottom pin where the brake shoes rest gets quite a bit of pressure through braking and unless it's welded super strongly, the weld will let go. Maybe you can find someone to do a really great welding job on it. With that pin loose, you will never get firm single-pump braking because there will always be a bit of play in the system. That's my view - I sympathize with your frustrations with trying to keep an old Rover going, I have certainly felt that way at times. It's fixable, though.

Tom