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Old 06-14-2023, 11:01 AM   #48
dsraven
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Join Date: Nov 2010
Location: calgary alberta
Posts: 7,858
Re: Moody's Utah 58 Apache

assuming all is good, parts wise, this is how I go about a drum brake adjustment. I assume I will get comments but this always works for me.
back off the park brake adjuster so that takes the park brake out of the equation. I do this because the brake shoes basically have 2 ends. one butts against the star wheel and the other end butts against the anchor pin at the wheel cylinder end. the shoes are not out and touching the drum until the star wheel is adjusted at the bottom, the park brake is applied or the service brake is applied. the star wheel only adusts that end of the shoe and the other end is adjusted by the park brake adjustment. a lot of guys think they can do without the park brake and these would be the guys that need to "pump the brakes" because the shoes get retracted back until they contact the anchor pin at the wheel cylinder end of the shoe. this makes the wheel cylinder pistons also retract fully which means when the brakes are applied the pedal does a full stroke but still doesn't supply enough fluid to push the shoes out enough to contact the drums at the wheel cylinder end.
anyway
with the park brake out of the picture I adjust the star wheel until the wheel is locked and won't turn. this ensures the shoes are fully out against the drum. then I back the star wheel off a number f clicks (count them) until the wheel will turn wioth only a slight drag from the shoes. I mean slight here, just a little noise no binding. now do the same on the other side and adjust the same number of clicks on the star wheel. let me also say you should make sure the star wheels are a set because some have a courser thread than others or may have a different number of points on the star portion. anyway. lock them, then back them off the same amount. this sets up the star wheel end of the brake shoe but the wheel cylinder end also need to be adjusted so the shoes are within limits and will contact the drums with a resonable amount of pedal stroke and fluid movement in the system. so, next adjust the park brake. adjusting the park brakeshould also not resu;t in a big brake drag. remember that a new set of shoes and drums will need to "wear in" so the arc of the shoe lining matches that of the drum inner diameter. this may take a bit of time and use. also, the new linings will need to be burnished (google that for a description) which basically means they need to get heated up with a few brake cycles so that the lining material can transfer onto the drum surface and smooth out the small imperfections and allow the linings to do their job properly. with that said, with new brakes you may need to do a few low speed stops in reverse to self adjust the shoes. some vehicles don't have the self adjust option so manual adjsutment may be required after the linings wear in to fit the drums etc.
so, to recap, loosen the park brake fully
adjust the star wheel tight, then back off until little or no drag. count the clicks as you go, do both sides the same. wheels should turn easily
adjust the park brake to allow a normal lever or pedal stroke for that system and also so little or no drag on the brakes with park brake released
adjust front brakes the same way except there is no park brake adjustment. this points out the need to have the lining wear within limits and also the drum diameter within limits. because there is no adjuster at the wheel cylinder end things need to be within manufacturers spec for the system to work properly and not require a lot of pedal stroke to get the linings out against the drum
now, with a service brake application, the pedal should have a decent height off the floor and should be firm, not spongy. if spongy try bleeding the brakes untiul clean fluid comes from each bleeder screw and no bubbles appear. personally I like the lisle "one man bleeder" as they seal pretty well against the bleeders screw and don't require 2 people to synchronize stepping/holding/opening/closing/releasing. when bleeding remember that the bleeder screw also becomes a leak point if unscrewed too much as they leak around the threads. the vacuum pump style bleeder is also a decent way to bleed brakes as well as the pressure bleeder that goes on the master cylinder in place of the cap.
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