Drums won't fit over the new brake shoes.

Posted By: rarefish

Drums won't fit over the new brake shoes. - 10/27/08 02:20 AM

I just installed a new set of Wagner front brake shoes on my 68 Charger R/T. The shoes are the 11"x3" I first ran the adjusters all the way in before attempting to reinstall the drums. I was able to get the passenger drum on with a lot of effort, but I could not turn the drum at all once it was on. The driver would only go on about half way over the shoes. I decided to not try and force it any more, so I removed it at that point. The drums are very clean. There is no lip on the front edge.
One thing that I noticed was the linings on the secondary shoes are about .050" thicker at mid shoe than they are near the top of the shoe. The lining then gets a little thinner as you go down the shoe. The linings thickness of the primary shoes do not vary through out their surface and are about .050" thinner than the secondary ones. I would think the lining thickness would be the same on all of the shoes and not vary.
Has anyone else seen this or ran into this problem?

Posted By: RapidRobert

Re: Drums won't fit over the new brake shoes. - 10/27/08 02:23 AM

never have, but they're the wrong ones.

Posted By: pishta

Re: Drums won't fit over the new brake shoes. - 10/27/08 02:37 AM

Perhaps the brake cylinders were not completely bottomed out (compressed) I usually take off the MC cap and force the fluid back up into the system with pressure on the shoes, and relaxing the adjuster. Then you mount the drum, pump the brake once and dial the adjuster out until you cant spin the tire one complete revolution, then pump it once more and adjust again. Yes, brake shoes are a bear when the darn drum doesnt wanna go back on.

Posted By: 1_WILD_RT

Re: Drums won't fit over the new brake shoes. - 10/27/08 02:58 AM

Quote:

One thing that I noticed was the linings on the secondary shoes are about .050" thicker at mid shoe than they are near the top of the shoe.

That is done to compensate for a drum that has been turned, typically back when it wasn't recognized as a health threat we would grind brake shoes so the radius of the shoe face matched the brake drum...If you don't do this & install the new shoes only a small portion of the lining will touch...Now they arc the shoes to near the max drum size & let them wear in...Grinding shoes became illegal many years ago & the equipment virtually doesn't exsist anymore outside of a manufacturing facility...

If your brake shoes are both touching the anchor pin at the top & fully seated to the adjuster at the bottom the shoes could be made wrong...

Posted By: pishta

Re: Drums won't fit over the new brake shoes. - 10/27/08 03:09 AM

Quote:

Quote:

One thing that I noticed was the linings on the secondary shoes are about .050" thicker at mid shoe than they are near the top of the shoe.

...Grinding shoes became illegal many years ago & the equipment virtually doesn't exsist anymore outside of a manufacturing facility...

We had one of these machines in our auto shop at my 100 year old high school. I thought it was the strangest machine, "who would want to grind their new shoes down?" It became obvious when we turned a drum and then looked at the radius compared to a new shoe. We also had a Sun distributor machine, an armature lathe/cutter and a small valve grinder on the same table, all could have been 40's vintage.

Posted By: 1_WILD_RT

Re: Drums won't fit over the new brake shoes. - 10/27/08 03:13 AM

Armature grinder...Or Growler? I've used those too...

Though both technologies were on their way out when I started working on cars...I just located a Distributor machine I'm trying to acquire..

Reread your post, armature lathe..

After that you need to undercut the mica insulators...

Posted By: pishta

Re: Drums won't fit over the new brake shoes. - 10/27/08 03:19 AM

Yes, it had that too. This was a machine you actually chucked an armature into and it spun it and you cranked the cutter across the copper face to make it smooth, then you turned on a small cutting wheel and moved it across the divisions to clean them out. I cant remember what you did first, but we took some of those cores down to nothing playing with that machine.

Posted By: rarefish

Re: Drums won't fit over the new brake shoes. - 10/27/08 03:20 AM

The shoes are seated on the anchor pin at the top and on the adjuster at the bottom, so I'm sure the wheel cylinder is not the problem.

Posted By: pishta

Re: Drums won't fit over the new brake shoes. - 10/27/08 03:23 AM

Bust out the body file and hit the high spot, I mean what else can you do? Once you get the drum on, the high spots will wear down quickly under use.

Posted By: DZJim

Re: Drums won't fit over the new brake shoes. - 10/27/08 06:13 AM

Quote:

Quote:

One thing that I noticed was the linings on the secondary shoes are about .050" thicker at mid shoe than they are near the top of the shoe.

That is done to compensate for a drum that has been turned, typically back when it wasn't recognized as a health threat we would grind brake shoes so the radius of the shoe face matched the brake drum...If you don't do this & install the new shoes only a small portion of the lining will touch...Now they arc the shoes to near the max drum size & let them wear in...Grinding shoes became illegal many years ago & the equipment virtually doesn't exsist anymore outside of a manufacturing facility...

If your brake shoes are both touching the anchor pin at the top & fully seated to the adjuster at the bottom the shoes could be made wrong...

Hah! Haven't done a brake job in 40 years, and was wondering what they do nowadays, since making asbestos dust became politically incorrect. One would think that the newer friction materials wouldn't be a hazard to arc grind to fit the drums...

Posted By: therocks

Re: Drums won't fit over the new brake shoes. - 10/27/08 10:41 AM

Biggest problem Ive seen why drums wont go on is there is a lip on the drum from rust and crud.Same when they wont come off.That and Ive seen the park cable hang and move the E bar a bit.It dosent take much.Have you turned the drums?Ive had some brakes even with new shoes and new drums that are just snug.Then when you use them once oe twice they seat.Rocky