adjusting manual drum brakes

[redtail]

I have manual 11 inch drums all the way around on my '68 and have had a hell of a time with a mooshy brake pedal. I have bled the crap out of them, replaced the hoses (all the rubber lines) and some of the steel ones as well. I have no leaks, but the brakes are mooshy.
Right now I have to do one pump and then I have a good solid pedal, it seems that the shoes are too far from the drum face?? I can hear the brakes expanding on the first pump, so I am pretty sure there is no air in the system, but I may be mistaken... but my question is how much should the brakes rub when I adjust them out? barely a skuff or should they make half a rotation with the tire off the ground...? more or less?

I also put on a fresh master (and yes I bench bled it)

this bronco has me pissed... I have set up three other drum brake systems with no problems. been fiddling with this on and off for the last year. Maybe broncos have some trick to them?? haha thanks for any help!

 

[Viperwolf1]

I like to adjust them for about 1/2 rotation of rub. They should still easily turn by hand.

 

[redtail]

ok. That seems to be what I have now... any other ideas? If I crank down on the brake adjusters more it seems to get rid of the softness, but then they don't roll properly...

Oh, and the manual master seems to leak out of the top really badly almost like the seal isn't holding or something. this happened with my one year old master and the new master I put in a couple weeks ago.

all new wheel cyls and brake pads have no wear on them.

 

[matts70]

Some people have luck adjusting their drum brakes. Not me. That's the only reason I switched to disk brakes. They don't stop that much better in my opinion, but I was sick and tired of trying to get my fronts adjusted--they either were grabbing WAY too much where the wheel wouldn't make a full spin, or I'd back them out and you'd have to stand on the brake to get the damn thing to stop! I had 100% brand new parts at the time as well. For whatever reason, I've had no problem getting my rear drums to adjust properly, though.

 

[70_Steve]

and brake pads have no wear on them.

That may be the issue.

The brake shoes need to wear into the curve of the brake drum. I seem to remember, way back when, there used to be a machine that would do that for you. That is, it would grind the face of the brake shoe to match the curve of the brake drum. This seemed especially important if the drums had been turned, since the inside diameter increases.

It may be that all you need to do is to wear in the brake shoes.

 

[blubuckaroo]

I like to adjust them up tight with the adjusters to get out all the slack, then back them off till the linings just clear. Yes, back in the day we would arc the linings to match the drum. Not as important on the rear as it is in the front since the front steer the car. Nowdays everything has front disc brakes. That's probably why I havn't seen a brake shoe arching machine in over twenty years.

 

[DirtDonk]

Same here. Used to be standard practice to true the shoes to the drums. In fact, I don't remember ever buying brake shoes or a clutch disc from a normal auto parts store back then. We used Bay Area Friction for new and re-built products that were always top notch and worked perfectly.

I always run my shoes up fairly tight too though. Till you could hear light scuffing for the entire turn. Even when trued, there seemed to be a bit of a light spot that I would take up slack in before I considered it adjusted.
If taking up that slack made the drums too hard to turn, then the shoes were not true enough and should have been re-done. I don't think that ever happened though, until we started buying and using off-the-shelf parts.

To my mind then, two things can cause a drum brake system to be mooshy. Assuming all the air out of course, it's either not quite adjusted up as hard as it could be, or you're lacking a residual pressure check valve.
Even there though, with a missing valve, if the shoes are adjusted up tight mechanically, there is usually not enough pull-off to even need a valve I wouldn't think.
It's only when the shoes wear (and the automatic adjusters invariably stop working) and more clearance is present, that the residual pressure check valve would really come into play.

If you want to see how much of your moosh is shoe adjustment, drive along at a normal speed and apply the parking brake till it clicks one notch. When you reach that notch, does the vehicle slow noticeably? If not, does the pedal firm up?
If so, then I'd say you should make your shoes tighter.

Oh, and are you always making sure to put the Primary shoe (shorter friction material) to the front?

Paul

 

[ugly74]

I've had really good luck tightening them up almost to the point that you can't turn the wheel by hand, and then backing them all off equal amounts. I like to hear 'em drag a bit, but without a lot of resistance. mine brakes nice and straight

 

[jw0747]

tighten adjuster all way down (tight) so that wheel won't turn at all. then back adjuster off some until wheel can be turned but there is still some resistance and you can hear sound of the shoes against the drum. once driven and brakes applied shoes will seat properly. another thing I always did was remove the self-adjuster apparatus and trash it. learned this from an expert back in the 60s and it has worked every time since.

 

[redtail]

how do you make the bottom stay together when you take the spring and all that out?

 

[jw0747]

the self-adjusting spring is only there for operation of the self-adjusting lever so that it returns to its resting position. it doesn't hold the shoes in place. springs at top do.

 

[ugly74]

the self-adjusting spring is only there for operation of the self-adjusting lever so that it returns to its resting position. it doesn't hold the shoes in place. springs at top do.

that may be true, but I still leave mine intact. if it's all clean and lubed right, they do self adjust. I don't feel like crawling underneath and adjusting the brakes every few thousand miles.

 

[jw0747]

that may be true, but I still leave mine intact. if it's all clean and lubed right, they do self adjust. I don't feel like crawling underneath and adjusting the brakes every few thousand miles.

brakes don't need adjusting "every few thousand miles" unless for some reason you're driving with your left foot resting on the brake pedal. actually most people don't know how to operate the self-adjuster thinking it's doing something by itself while you drive.

 

[ugly74]

brakes don't need adjusting "every few thousand miles" unless for some reason you're driving with your left foot resting on the brake pedal. actually most people don't know how to operate the self-adjuster thinking it's doing something by itself while you drive.

yeah well, I don't drive mine like a little old lady. lotsa gas, and hard on the brakes. baby it, I do not. ;D

what is it exactly that actuates the adjusters? it's braking in reverse, right?

I just don't see why to remove parts that would keep it from operating as intended

 

[Viperwolf1]

what is it exactly that actuates the adjusters? it's braking in reverse, right?

I just don't see why to remove parts that would keep it from operating as intended

Correct, applying brakes while moving backwards is all it takes. No good reason to remove the adjusters. You would need to come up with a spacer to replace them if you did.

 

[jw0747]

Correct, applying brakes while moving backwards is all it takes. No good reason to remove the adjusters. You would need to come up with a spacer to replace them if you did

correct way to actuate is go backwards w/speed and apply hard brake pedal.
good reason to remove them is they don't work half the time as they get older and...what spacer? never had a spacer on mine or any others I saw with them removed.

if you like them and believe they're necessary, keep them on. and each to his own. every set I ever had was trashed starting with first brake job on my new '63 Fairlane in '64. there's just something about crawling under a vehicle and hand adjusting them that makes my day complete. ;D

only way to go nowadays is discs on all 4 corners.

 

[redtail]

correct way to actuate is go backwards w/speed and apply hard brake pedal.
good reason to remove them is they don't work half the time as they get older and...what spacer? never had a spacer on mine or any others I saw with them removed.

if you like them and believe they're necessary, keep them on. and each to his own. every set I ever had was trashed starting with first brake job on my new '63 Fairlane in '64. there's just something about crawling under a vehicle and hand adjusting them that makes my day complete. ;D

only way to go nowadays is discs on all 4 corners.

if only i had the grand or so to upgrade it thanks for the tips guys