wallytoo

iTrader: (1)

not a bad theory. might be correct.

if there is any pitting, you'd need to remove a bit of material via honing. your original cups and pistons would be rendered too small in diameter, and will leak. if you really want to rebuild them, you need to bore and hone, and then match cups/pistons with new bore. if there were no source for wheel cylinders, this would be a good alternative. however, with readily available replacements, rebuilding the originals is not cost effective at this point in time. perhaps in the future, it will be.

wally

wallytoo

iTrader: (1)

this is the tool i use for removing sping "A".

https://www.summitracing.com/parts/o...MobileSwitchNo

ewong

I cant seem to figure out how to use that to remove or reinstall spring A.....

millball

There's a little socket on one handle end that you place on the spring stud and turn it to cam the spring end off the post.

scope103

I'm not a fan of throwing away "good" parts, but gee whiz, a complete replacement wheel cylinder from RockAuto runs from $21 down to $4!

Yeah, these are aftermarket parts (Toyota runs about $65-$70 at an online dealer), but your originals lasted 31 years. Are you afraid the replacements will only last 25? 15? How long do you think you were driving with your scarred cylinder?

wallytoo

iTrader: (1)

the hook is inserted into the coil portion of the spring. the straight tip is inserted into the slot in the brake shoe where the spring hook end goes. close ends of pliers together, and guide the spring hook into its slot. it takes practice, but i've used the tool on multiple vehicles over more than 20 years.

wallytoo

iTrader: (1)

not on spring A. use the pliers method as described in the post above. the cam action is used where an anchor post is employed - for these, there are usually two springs that attach at the anchor, and the cam tool end will easily slip the spring hooks off. my cj uses this action.

RAD4Runner

OEM have been discontinued so I'm perfectly happy with the NAPA ones.

I'm sure the scars/rusts/pits developed over time in the area where the cups do not scrape/clean anymore because they had to push farther out to operate the thinner brake shoes. The cups themselves are in excellent condition (here), as well as the cylinder wall where they operated on, so they could easily work for the life of the truck, except that the thicker new pads pushed them back on the rusted/pitted wall surface (illustration).

Lessons learned:
(Searched for "rear brake" and rear brake cylinder" but found nothing so here goes...)

I recently checked and ended up replacing my rear brake shoes. The shoes part was uneventful, although proper tool for removing and re-installing the return/tension spring would have been nice.

After the shoe replacement, left brake cylinder leaked. NAPA carries replacement cylinder for $16. I replaced them at NAPA parking lot. About a week later, the right side cylinder leaked, too. Replaced with NAPA part again without any issues.

LESSONS LEARNED post-mortem (Not much I could have done because truck was 30 years old when I got it):
1) Good idea to flush and refill brake system, including the cylinders and calipers if possible. Dirty / old brake fluid promotes / allows rust in cylinder.
2) Rubber cups keep the cylinder wall that they rub against clean, smooth and free of rust. As shoes get thinner, the rubber cups inside the cylinder
operate farther and farther away from the center of the cylinder. The part of the wall closer to the center of cylinder where the cups do not rub anymore get rusted / pitted. After replacing with new brake shoes the cups and pistons will now operate closer to the center of the cylinder again - right on the rusted wall surface. This will break seal against the wall and cause a leak.
3) Cylinder can be honed, but even if the rubber cups, pistons, and seals and are still in good condition like mine (here) and (here) were, they might be too small for new cylinder bore size. Tools, supplies, and time could cost more than new replacement (and even OEM if you can find it).
4) Always have spare brake cylinder or rebuild tools and supplies readily available when replacing old brake shoes where above conditions apply.
5) This problem may not occur on front disc brakes where brake pads are replaced more often, so cups and pistons are pushed back toward the center of the caliper before rust develops.

NYHumpinUtah

iTrader: (1)

Wow, you were close to me. Insteed of making a right at St. George you just go straight about 40 miles and you're here!
Next time

RAD4Runner

Awesome, man! Sure, next time.

RAD4Runner

BTW, based on wallytoo's experience as shared on separate thread, AVOID bendix brake shoes #PB568 from rockauto.
"tabs at the wheel cylinder end were too long, and wouldn't allow the drums to fit back on"