Frustratingly braked out!
Subjuect vehicle: '83 K2500 Sub with 13" drum brakes
Symptom: Low speed (parking deck speed), rear brakes are locking up and will drag. It is very random but always seems to be at low speeds and it is worse when turning. It doesn't seem to do it at higher speeds and the wheel/lugnuts are not hot to touch after a trip.
R&Red: Replaced master cylinder twice, replaced leaky proportioning valve, replaced rubber brake line down to the axle, replaced all rear brake hardware (springs, adjusters, etc.), new shoes, turned drums, replaced wheel cylinders, loosened parking brake cable, adjusted shoes in and out multiple times, bleed the system multiple times, even ground down the small wear ridges on the backing plate where the shoes ride.
I really have no idea what to do next. After I work on it, it seems to not do it for a few days, then it starts showing up again. I haven't checked any steel lines yet. Could there be a blockage? If so, it would seem to be more consistent and not so random. One more note, it seems to be both sides that are randomly locking up but more so on the right - enough to make it pull to the right. I keep thinking it's the front but after it happens, I look at the back tires and see "skid" marks on them.
Last edited by Subzilla; 12-09-2010 at 07:15.
Mark Chapman DP member #653;
1983 K2500 6.2 Suburban, 4" lift, 35" tires, ATS turbo, Banks exhaust/intake, pyrometer, tachometer;
1986 K5 6.2 Blazer, 2" lift, 33" tires, Banks intake, pyrometer, tachometer
1963 wife, one owner, average mileage for the age but in excellent shape, a keeper
1992 daughter, low mileage, pretty, limited edition, but requires some money to maintain
1995 son, sports model, very fast & peppy, time will tell on durability and maintenance costs
"Grease is good"