Wheel cylinder leaking

[iLikeEggs]

The max diameter should be stamped on the edge or outside of the drum. It's a DOT requirement.
Unless they are grooved or pitted they usually always "look good". if they are worn beyond the run out spec then the wheel cylinders can push the brake shoes out too far. If you take a wheel cylinder off th backing plate still connected the brake line and step on the brake pedal the pistons blow out. If a drum is out of spec the wheel cylinders may be able to push too far out.

 

[SunlitComet]

these are inside dimensions on machined surfaces. for 10"drum you can refinish to a max of 10.05". they must be discarded at 10.09"

i asked the details becuase i was concerned about the drums used and condition of them and other parts. if it happens always in the same are it leads me to be believe the brake shoes are expanding out further they they should because something is over worn. a detailed inspection of every part in there is a good idea.

 

[Oldyukon95]

Yeah I think I'm going to take it to a shop. I just hate doing that.

 

[iLikeEggs]

Brake inspections at reputable shops are usually free of charge. A competent shop will not only just inspect the pads and shoes, but measure the rotors and drums. They should put the minimum specs and actual specs for each wheel on your work order if they don't, and try to sell you a "hang and turn" then say thank you and find another shop. if any shop tries to charge you for your brake inspection then run the other way. I'm talking commercial, not dealer. Dealerships are a different animal. Dealerships don't do brakes any better than Sears, Pep Boys or Les Schwab or Brake Team, etc. Although your mileage may vary with different shops.
Whatever shop you go to, ask if you can talk with the technician who inspected it. Tell them what you have been dealing with. Yes, these guys are often/usually paid by the labor they generate but the majority of them do care about their reputation. The good technicians know that if they are accurate and honest then they will have referral and repeat business.

 

[Oldyukon95]

Thanks that's good advice