Re-arching brake shoes

[wdfifteen]

I put new brake shoes on the Speedster and the brakes are HORRIBLE - worse than the old dried-out, glazed shoes I took off. ! I pulled up an old racing trick and put some chalk on the shoes and drove the car to see what the contact pattern was. On the left it's about 10% of the shoe surface and on the right it's about 40%. I obviously need to get the shoes fitted to the drums, but can't find anyone who does this anymore. Has anyone done any DYI brake shoe fitting?

[DanielDudley]

Do you think new shoes and drums together would match better?

If I was looking for drum brake specialists, I'd get a copy of Hemmings.

[john walker's workshop]

We use Seattle Brake and Clutch here. Perhaps the same sort of outfit there.

[Shaun @ Tru6]

I think Daniel has it right, get new drums and shoes together. If you don't want to do that, you would have to send your drums and old shoes out to be relined. I would think a relining shop would want your drums to make sure the relined shoes fit properly in them but just a guess.

[john70t]

(just guessing here)
If the contact is in the center, the drum is probably too enlarged or worn.
When they get thin those can crack if overheated.

If on the leading or trailing side, the pivot hardware or piston may be worn.
There is usually an adjuster accessible with a flat screwdriver through a slot I think. Lube joints first.
Read backing off instruction specs.

Or the mfr may make them undersized to be used only with their own thicker or smaller diameter drum.

[Shaun @ Tru6]

Originally Posted by Zeke

You can give them the overall ID of the drum and they can set the arc to that radius. They certainly should be the same R to L on each axle.

That makes perfect sense.

[Jon B]

Originally Posted by wdfifteen

I obviously need to get the shoes fitted to the drums, but can't find anyone who does this anymore.

Find a shop that services truck brakes in your area, or send your brakes to CH Topping in Long Beach CA... Home

[wdfifteen]

Originally Posted by Shaun @ Tru6

I think Daniel has it right, get new drums and shoes together.

You two are going to kill me! Sure, I'll sell my house and buy a new set of Porsche front brake drums for a 1956 Speedster.
There are people who repop them. $8500.
But as near as I can tell my drums are close to 280 mm (stock) and I'd like to use them. The steel liners in these drums don't wear like cast iron does.

[john70t]

Return shoes as defective. Buy another brand.

[RWebb]

^ best answer

the old VW guys do it with a hand file

or... do you have a lathe?

[Shaun @ Tru6]

Originally Posted by wdfifteen

You two are going to kill me! Sure, I'll sell my house and buy a new set of Porsche front brake drums for a 1956 Speedster.
There are people who repop them. $8500.
But as near as I can tell my drums are close to 280 mm (stock) and I'd like to use them. The steel liners in these drums don't wear like cast iron does.

Whoa!

Then have some fun. I've got a 4X rivet gun you can borrow.

[PD41]

You just need to take your drums and shoes to any repair shop so they can measure each drum and arc the 2 shoes accordenly maybe . It is always good to put some braking miles on new shoes then re-adjust them.

Where did you get the shoes ?
Call these 356 brake guys.

https://mwthemachineshop.com/porsche-356-brake-drums

Bill Brown in Lincoln Nebraska sell 356 shoes.

[wdfifteen]

Originally Posted by PD41

You just need to take your drums and shoes to any repair shop so they can measure each drum and arc the 2 shoes accordenly maybe

Well, that’s the problem since I can’t find “any” repair shop that still does it. Thanks for the tip on the machine shop.

[Jon B]

Originally Posted by wdfifteen

I put new brake shoes on the Speedster and the brakes are HORRIBLE - worse than the old dried-out, glazed shoes I took off.

Also make sure that your drums haven't begun to flare ("bell mouth").
This was a problem on early Porsche drums, because they didn't have sufficient support on the open end.
The shoes will wear and deflect somewhat to make full contact, but the brake performance suffers.
The 60s 356B drums were much better in this respect.

If you look at the photos posted on CH Topping's Yelp page, you'll see a dozen 356 drums on the floor, including a set of Rudge drums.
Another photo shows a heavily finned RSK Spyder drum on their lathe. They do much of the vintage Porsche work in SoCal...

https://www.yelp.com/biz/ch-topping-long-beach

[wdfifteen]

After a couple of hours on the Google machine I found several places that will check the drums and arc the shoes to fit and even install new steel liners (and splines for the rear drums). I haven't found anyplace local, so shipping and waiting is in order. My couple of days project has just turned into a couple of weeks.
The good news is coming here and getting suggestions gets my curiosity up or something. I always have better luck finding solutions after throwing a question up to you guys, even if you don't have the exact answers I'm looking for.

[GH85Carrera]

Just order an upgrade kit for new Willwood disks and calipers!

I would have guessed the brake drums were expensive due to low demand and no new ones being made, but dang, I had no idea repops were that much money.

[wdfifteen]

Some pictures.



Right side backing plate before I took the shoes off.



Inside of brake drum.



The dark areas are where the shoes contact the drum. The left wheel shoes are on the right (). The contact is on the inside of the shoes, near the backing plate. It would seem the drums are the opposite of bell-mouthed.

[wdfifteen]

Originally Posted by GH85Carrera

Just order an upgrade kit for new Willwood disks and calipers!

I would have guessed the brake drums were expensive due to low demand and no new ones being made, but dang, I had no idea repops were that much money.

That's for a set of 4, making them "only" $2125 each.

[widebody911]

I had the same issue when I did the brakes on my '57 356A. I got them reasonably close using an air die grinder and 3M grinding wheels, using a mist of rattle-can paint as a guide coat; the chalk would probably work better.

I also roughed up the drum surface with 40-grit sandpaper. Brakes are nice and smooth now.

[GH85Carrera]

Originally Posted by wdfifteen

That's for a set of 4, making them "only" $2125 each.

I fully understand the differences. I got curious, so I looked it up. If I needed new rear drums for my Chevy El Camino they would cost $26.41 for new GM Goodwrench factory OEM drums. My original drums are still on the rear of my Elky and working fine, so I have not needed to spend the bucks for new drums yet.

That is a serious Porsche Tax, and age tax.

Good luck with getting yours working right. Good brakes are really nice things.