Brake Shoe Centering

29Cabriolet

29Cabriolet

Senior Member
Doing a complete brake job. Front was done this spring; now working the rears. Centering the front was relatively easy by bending the piece indicated in the pic. It was very close as installed, so it needed just a little tweak. The rear however was much further off – 0 at 9 o’clock about the thickness of the lining at 3 o’clock . In my first attempt I over bent by tapping with a hammer and small steel rod and ruined the part. What is the best method for making this adjustment?
 

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FWIW: Just several experiences while working with old used backing plates with re-installed tracks:

If the original worn tracks were formerly removed, the original rivet holes in the backing plate may have been be slightly enlarged. If the tracks were removed several times, the newly installed tracks may be re-positioned even more off center.

Hence, when new original rivets are placed in enlarged backing plate rivet holes, prior to riveting, the new tracks are then able to move side to side and up & down, and if not riveted in their original positions, the improper track locations & incorrect original Ford dimensions from center of backing plate to rivets can cause the brake linings to be off center when applying the brakes.

This "exact" dimension from center of backing plate to rivet holes for the "front" backing plates seems to have been posted years ago on the AHOOGA Forum by Mr. Marco.

Even found that some rivet holes in old backing plates were welded solid & said holes were re-drilled in incorrect locations.

"If" one has original backing plates with original tracks, (with or without worn tracks), & if one wants to install properly positioned "new" tracks, not a bad idea to obtain dimensions from this original backing plate & draw a layout pattern of the exact location of the center of the rivets when measure from the center of the backing plates & install rivets in their proper position.
 
I have always repaired/adjusted the centering by welding up the surface and then grinding or filing to fit like Mitch suggests.
Good Day!
 
Just FYI for a few years the replacement rear tracks were not made properly and the pins would not line up correctly with the holes in the original backplates. Made a hell of a time adjusting them.
 
Might add that correctly made tracks from original Ford prints are now available if one buys them from vendors who offer them & correctly advertise them in writing as such.

Had no problem lately with those offered by Bert's & Bratton's -- there may be other vendors who have them -- others may want to chime in with past correctly made track experiences.

Take the time to properly install tracks, & one can do it once, thus saving lots of valuable Model A time trying to compensate for maladjusted off centered mechanical brake tracks.
 
The ones Ive installed in the past 2 years have been correct and required very little if any centering. But if you buy some old stock ones just be on the look out.
 
I weld and build up the old tracks on the backing plate without removing them. I grind the welds and test fit the lined shoes using a centering tool. An easier procedure for centering the rear brakes may be by grinding the tracks level and using flat head Teds square rear centering pins. The centering pins should be less expensive and less trouble than replacing the old tracks. Remember that the rear brake cams are full floating in the rear brake camshafts.
 
Brakes are on of my forte's..... As Purdy said... I also weld up the roller tracks and machine/grind to the correct spec for front and rear. it is more expensive and takes more time to replace them, and re-rivet them in than it does to repair them. In using a centering tool, either one of the new available from bratton or snyders or the KRW versions, Make sure they are equal. You can slightly.. ( mean slightly tweak the tracks up or down to get them there. I personally haven't used the square off rear centering pins with the flats... they don't sound like a bad idea. I would think they just have to have enough lube to keep them sliding.

Proper relining/arcing/centering, and brake adjustment will give you great breaking. Take your time, go through all the process and make sure each wheel is right.
Best of luck
 
FWIW:

Also, rear brakes always had floaters for much better equalization of mechanical brake shoe pressure; but original front brakes did not.

After discussing advantages of same with Mr. Charles Yapp years ago, I made custom front brake floaters with original wedge studs from instructions for same found in his "Secrets of Speed Magazine."

Manufactured front brake floaters help equalization & are now available to replace the original wedge stud for front brakes; part #2870 by Bratton's .......... & part #A2051-F by Snyder's.
 
H. L. Chauvin said:
FWIW:

Also, rear brakes always had floaters for much better equalization of mechanical brake shoe pressure; but original front brakes did not.

After discussing advantages of same with Mr. Charles Yapp years ago, I made custom front brake floaters with original wedge studs from instructions for same found in his "Secrets of Speed Magazine."

Manufactured front brake floaters help equalization & are now available to replace the original wedge stud for front brakes; part #2870 by Bratton's .......... & part #A2051-F by Snyder's.
Click to expand...

If you put floaters on the front brakes, doesn't the front shoe become the PRIMARY shoe and put added presure on the rear (SECONDARY) shoe, making it wear out much quicker than the front (PRIMARY) shoe?

Maybe you'd have to swap shoes when they reach the half worn point.
 
Actually, they self energise . As the wedge moves downward the pressure has to equalize, side to side . I use them with good results . They take care of side to side centering .
 
H. L. Chauvin said:
FWIW: Just several experiences while working with old used backing plates with re-installed tracks:

If the original worn tracks were formerly removed, the original rivet holes in the backing plate may have been be slightly enlarged. If the tracks were removed several times, the newly installed tracks may be re-positioned even more off center.

Hence, when new original rivets are placed in enlarged backing plate rivet holes, prior to riveting, the new tracks are then able to move side to side and up & down, and if not riveted in their original positions, the improper track locations & incorrect original Ford dimensions from center of backing plate to rivets can cause the brake linings to be off center when applying the brakes.

This "exact" dimension from center of backing plate to rivet holes for the "front" backing plates seems to have been posted years ago on the AHOOGA Forum by Mr. Marco.

Even found that some rivet holes in old backing plates were welded solid & said holes were re-drilled in incorrect locations.

"If" one has original backing plates with original tracks, (with or without worn tracks), & if one wants to install properly positioned "new" tracks, not a bad idea to obtain dimensions from this original backing plate & draw a layout pattern of the exact location of the center of the rivets when measure from the center of the backing plates & install rivets in their proper position.
Click to expand...

HL, not to sound dubious, but isn't calculating such minute clearances rather much of an impossibility for us amateurs? It seems to me you are talking about hundredths of an inch if not thousandths on a backing plate that is an irregular design, does not lie completely flat on one side, etc.
 
I have never replaced shoes in a Model A but will be doing front AND rear brakes soon and intend using an old brake drum on the rear with a hole cut in it to measure for centering the shoes. What do the experts say about this??
I have the floating wedge arrangement in the front brakes which I think probably makes centering a waste of time so long as the moving piece of rod has about the maximum room to slide.
Maybe I'm barking up the wrong tree and will see so when I get in there but input from those on this forum who know would be very welcome.
 
Usually the problem on the front is getting the shoes centered in the up and down direction. As the tracks wear, the shoes get closer to the drum at the bottom. as the tracks wear, the bottom of the front brake lining wears more . When new lining is installed on the shoes and the tracks are worn the shoes with new lining will be so far downward that the drums won't fit over the shoe. In such cases the tracks will need to be built up so as to raise the relined shoes enough so that the drums can be installed over them. The shoes need to be centered within the drums or you will get drag or not be able to get the drums on. This happens to the unknowing often and they can't figure out why the drums won't fit.
 
As for installing new tracks goes, I've never seen new tracks come very close to centering the brakes. In a perfect world, installing new tracks would center the brakes but when it comes down to the real nitty gritty every application will vary. I've found it to be easier and less expensive to just build up the tracks with weld without removing them and then center as needed. Its usually not an easy job for a novice. In most cases with the model A, you can't just install new lining and expect everything to fit back together and work as with more modern vehicles .
 
Hi Eric,

He says he is off about the thickness of the brake shoe lining, (more than hundredths or thousandths of an inch) & he already broke the metal track assembly while trying to tweak this larger fractional amount.

If after installing a new track assembly, he gets the same off center results, appears rivet holes in backing plate have to be corrected.

Difficult to guess at his exact problem without seeing same from miles away.
 
The installation of Flat Head Ted's brake centering kit overcomes the reliance on out of position or worn roller tracks. The front brakes self center without using the roller tracks. If you install what he calls "pins" on the rear brakes, which were in the past sold separately, it enables you to center the brakes on the tracks by selecting the right acentric on the pin. The pin is actually a four sided flat acentric that slides on a worn roller track. A side is selected to give the proper centering height.

I installed a set on my Victoria a few years ago and it greatly improved the brakes. You need a centering tool to center the rear brakes. I got one from Bratton's.

Tom Endy
 
Tom, You said " You need a centering tool to center the rear brakes. I got one from Bratton's." I've heard that cutting a hole in an old brake drum can be used to centre the brake shoes instead of one of those tools. I haven't done a reline on a Model A before but do you (and others) think it will work. Seems viable to me but like I said, I haven't been there.
Purdy, I take your point about centering them up and down. Looks like the welder will get some use (again)
 
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