Rear backing plates delima

[Steve Plucker]

I am trying to determine just why I can not get the rear hubs on my fully assembled rear backing plates.

When the backing plates are assembled to the rear axle and the brake wedges are fully bottomed out...the hubs will not go on.

I do not want to force them as I probably will not get them off.

Every part was looked at for quality, length, what ever.

The only thing on each backing plate that worries me is that I removed the old worn out tracks and put new ones on.

Brake pads are standard thickness...not oversized BUT one would think so but not.

So my question is this...if any of you are at this point...just what is the diameter of the assembled rear backing plate from brake shoe to brake shoe?

IF the repro tracks are to high, not standard, would that cause the shoes to protrude out just enough to not allow the hubs to go on?

Thanks.

Pluck

[Jacksonlll]

Sometimes the new emergency brake lining is way too thick.

[marty in Ohio]

Jackson is right. We put new brakes on a '30 coupe last week with new service brake shoes and new emergency brake rings. We couldn't get the drums on and ended up putting the old E-brake rings back on. They weren't really worn out and after all they don't stop the car - they only hold the car.
Marty

[latecomer]

Are you absolutely sure the adjusting is wedge drawn in completely?

[Steve Plucker]

Originally Posted by Jacksonlll

Sometimes the new emergency brake lining is way too thick.

The E-brake shoes were not attached to the assembly at the time...But good thought!

Pluck

[Steve Plucker]

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Originally Posted by latecomer

Are you absolutely sure the adjusting is wedge drawn in completely?

Yes I am.

Pluck

[Purdy Swoft]

I grind a taper on the leading and trailing ends of the service brake lining . I grind the taper all the way from the ends of the new lining to the outer ends of of the brake shoe . In most cases the ends of the lining can slightly kick outward when the end rievits are installed or the lining could be a small amount too long . a taper on both ends of the lining will reduce the width of the lining from end to end and allow the necessary clearance needed to install the brake drums .

[Dave in MD]

Pluck,
Some of the older reproduction adjusting wedges did not have an undercut where the threads meet the wedges. This would cause the wedge not fully retract.
Dave

[Chuck Sea/Tac]

Are you using new cast iron drums?
By the way, nice article in the restorer!

[Steve Plucker]

Originally Posted by Purdy Swoft

I grind a taper on the leading and trailing ends of the service brake lining . I grind the taper all the way from the ends of the new lining to the outer ends of of the brake shoe . In most cases the ends of the lining can slightly kick outward when the end rievits are installed or the lining could be a small amount too long . a taper on both ends of the lining will reduce the width of the lining from end to end and allow the necessary clearance needed to install the brake drums .

Good thought Purdy...But that was done before I mounted the shoes.

Pluck

[Steve Plucker]

Originally Posted by Dave in MD

Pluck,
Some of the older reproduction adjusting wedges did not have an undercut where the threads meet the wedges. This would cause the wedge not fully retract.
Dave

Dave,

Using very good original adjusting wedges...Great thought.

Pluck

[Steve Plucker]

Originally Posted by Chuck Sea/Tac

Are you using new cast iron drums?
By the way, nice article in the restorer!

No...Original drums with good thickness and very round.

Thanks Chuck...I know it was cluttered with numbers but had fun doing it.

Pluck

[Y-Blockhead]

Are your shoes centered in the backing plate? Check the tracks. Should be 1" from rivets to top edge of track (per Red Book page 1-41).

Originally drums are ~11" ID. Check from shoe to shoe to ensure they are less than 11". Check shoes if they are arced correctly. (Shoe arc matches drum arc).

Brake centering tool https://www.brattons.com/brake-shoe-centering-tool.html

[larrys40]

Im with y-block that I would make sure shoes are centered. Also, if you back the wedge out sometimes it can cause the brake shoe actuating links A-2042 to not fall into the wedge recess and cause the shoes to stick out. This is especially apparent with new cast iron 11.0
Drums. You can also check to see where things are contacting with a little chaulk in the outer edge of the shoes. Fit without the e brake lining attached which I believe you already are doing from what’s been stated.
I have also seen incorrect seals or thie that are one’s with hard leather or rubber to be difficult to fit over the housing race.
As was stated use a centering tool to ensure shoes and tracks and proper shoe placement. Resolve if not.
Larry shepard

[CWPASADENA]

Originally Posted by Y-Blockhead

Are your shoes centered in the backing plate? Check the tracks. Should be 1" from rivets to top edge of track (per Red Book page 1-41).

Originally drums are ~11" ID. Check from shoe to shoe to ensure they are less than 11". Check shoes if they are arced correctly. (Shoe arc matches drum arc).
Brake centering tool https://www.brattons.com/brake-shoe-...g-tool.htmlxxx

Very important!!!


The shoes have to be arched correctly AND the shoes centered or there may be problems exactly like you are describing.


Chris W.

[Kurt in NJ]

---do the shoes look centered on the backing plate visually -----if the drum is held in place can you work a feeler gauge in around the edge of the shoes---if they are off center you should be able to feel it that way

The Barrett Brake doktor fixes all ---fits shoe to drum, concentric to the axle

before the shoes were installed how did they fit to the drum---gap in center---gaps on ends?

The aamco 1750 shoe centering gauge --the black adapter fits ford rear axle ends ---for checking /adjusting centering of shoes

[Steve Plucker]

Stay tuned guys...Got a few things to do before I get back to this...this is driving me nuts but will double check everything again against some different backing plates with ORIGINAL tracks in excelent condition.

In the mean time...Kurt you can drop by anytime!!!

Thank you for some great tips!

Pluck

[Mel Gross]

When we rebuild backing plates and are done, we always fit / try them in the cast iron brake drums we are either sending with the backing plates or with cast iron brake drums that we have on our shelves. This is done on both the fronts and rears. Our rear backing plates are completely assembled with the emergency brakes system attached to the backing plate. This way we know we done the job right. If there is a problem at the time of installation, then in almost every case the problem was centering of the backing plate.

[ljaynavl]

I am just now joining, but seem to be having a similar issue and would appreciate some guidance. I am rebuilding the back brakes and replaced the roller track assembly, purchased new cast iron drums/hubs and had the shoes arced. I see that the shoes aren't centered while the adjusters are turned all the way down so I believe that much has been eliminated.
I suspect that the roller track is off slightly (by perhaps .010) on the 'upper' side though there was no real adjustment when bradding in the new plate.
The drum won't go on all the way as a result. It seems that sanding the shoes down will lead to unintended consequences.
What now? Do I need to get new backing plates with the roller plate centered better? How does one adjust the shoes in a situation like this?
Thanks to all with ideas!

[Purdy Swoft]

The shoes can usually be centered by either building up the tracks with weld and grinding down to the proper level or just grinding the tracks if they are already two high . The brake centering tool will let you know when the shoes are centered . Installing new brake tracks is no guarantee that the shoes will be centered .