disc/drum diagnosis help needed

-

Rapid Robert

Well-Known Member
Joined
Aug 6, 2006
Messages
2,144
Reaction score
552
Location
Lincoln Nebraska
73 dart OE disc drum. pedal goes almost all the way to the floor & it does not pump up. pulled one front/rear (hard to get the lug wrench on the nuts on the mag wheels so just did one side) & up front one pad of the two was pretty thin as was one of the linings on the left rear & the drum did not seem loose on the linings when I pulled it. M/C is about 3/4 full. any thoughts on what might be the problem here? thank you for your time. RR
 
Adjust rear brakes .
Mosta your pedal travel is going into moving the shoes out to the drum, adjust them up, pedal travel will reduce .
Cheers
 
Last edited:
the one (rear) side several lug nuts were too tight for the 4 way to break em loose. should I get a breaker bar or rent an impact? I was thinking maybe the impact shocks em loose with less chance of breaking off a stud. what do you think?
 
I usually use a breaker bar if my 1/2 impact won't do it.
Are you turning the proper way ?
Driver's side can be LEFT thread .
If visible, end of stud should have "L" stamped in it .
 
73 Dart, so all should be RH threads. But anything is possible. Maybe had a few LH from 72 so put it on an early 73. No sense throwing them away. Could be a bad M/C with fluid pushing past the piston.
 
Why are your pads wearing unevenly? The pistons have limited travel. New pads will correct this by pushing the pistons back in the bores.
 
73 dart OE disc drum. pedal goes almost all the way to the floor & it does not pump up. pulled one front/rear (hard to get the lug wrench on the nuts on the mag wheels so just did one side) & up front one pad of the two was pretty thin as was one of the linings on the left rear & the drum did not seem loose on the linings when I pulled it. M/C is about 3/4 full. any thoughts on what might be the problem here? thank you for your time. RR

What's the back story?

Have the brakes ever worked correctly? Have you made any changes recently? Was this something that happened suddenly or is this a car that's been off the road for awhile?
 
yes I thought that was strange that the one pad was real thin & the other thick on the LF. the stuck lug nut was on the RR. when I adjust em should I have the rear up on stands & it idling in gear & adjust till I hear a light tick during one revolution? EDIT BLU I just saw your post. car has been not driven in awhile but I dont remember pedal being that low. no changes at all in that time.
 
I just had pads that were eating up the rotor on the passenger side of my Ram. Bottom line the 20 year old caliper piston was frozen and would not retract. New calipers, pads and rotors fixed me up. By the way the new calipers have a plastic piston which will probably prevent this from happening again. Don't think I'll get another 20 years out of the truck though.
 
yes I thought that was strange that the one pad was real thin & the other thick on the LF. the stuck lug nut was on the RR. when I adjust em should I have the rear up on stands & it idling in gear & adjust till I hear a light tick during one revolution? EDIT BLU I just saw your post. car has been not driven in awhile but I dont remember pedal being that low. no changes at all in that time.

A few things-

If the car has been sitting for awhile the brake fluid may have absorbed a bunch of water. That can cause a soft pedal that doesn’t pump up (unlike air, which will cause a soft pedal that will pump up). Brake fluid will absorb moisture out of the air over time.

It’s also possible that you’ve lost a seal in the master cylinder, causing the fluid to leak past the seals and giving a soft pedal

For the uneven pad wear, it’s a single piston caliper set up so the whole caliper has to slide smoothly to wear the pads equally. If the caliper doesn’t slide on the caliper bracket, you’ll wear out one pad faster. You’ll want to make sure that the caliper piston moves freely, but if you have slider type calipers you may want to inspect the sliding surface on the caliper brackets

For uneven wear in the rear, it’s possible you have a plugged brake line or collapsed brake hose. Check the drum that has the thick brake pad lining to make sure you’re getting good fluid movement on that side. It also could be that the adjuster on that side isn’t working properly.

To adjust the rear drums you’ll want the car up on stands but running is absolutely not necessary or advised. You just need to adjust the star wheel until you feel the brake drag a little when you spin the wheel (by hand!). Once you feel the brake start to drag, back off the adjuster one click.

But yeah, worth pulling the wheels and making sure the adjuster parts are all present and working properly. Especially on the side that wasn’t wearing as much.
 
[1] You should fit auto adjusters to the rear drums. They work & keep the pedal high.
[2] If you have a low pedal, but the pedal is hard, & you cannot pump up the pedal, that suggests an internal problem in the m/cyl. The m/c is probably made out of Detroit's wonder metal, cast iron. They rust. The seals get pushed over rusted sections as pedal travel increases & this can damage the seals, cause internal leaks.
 
top notch info. I will get on it, thanks guys. RR EDIT last question: would you know that on each side do I contact the star wheel at the top & move the star wheel down or down & ratchet it up? I dont want to unscrew it if thats possible. thank you
 
Last edited:
top notch info. I will get on it, thanks guys. RR EDIT last question: would you know that on each side do I contact the star wheel at the top & move the star wheel down or down & ratchet it up? I dont want to unscrew it if thats possible. thank you

What sucks is when you over tighten the adjuster then have to reach in there and push the adjuster arm away from the adjuster wheel and back the wheel off at the same time.:D

Done that a bunch.
 
[1] You should fit auto adjusters to the rear drums. They work & keep the pedal high.
[2] If you have a low pedal, but the pedal is hard, & you cannot pump up the pedal, that suggests an internal problem in the m/cyl. The m/c is probably made out of Detroit's wonder metal, cast iron. They rust. The seals get pushed over rusted sections as pedal travel increases & this can damage the seals, cause internal leaks.

at 73 he should have self-adjusters.

i know they can get gummed up and limit the function, but still.
 
top notch info. I will get on it, thanks guys. RR EDIT last question: would you know that on each side do I contact the star wheel at the top & move the star wheel down or down & ratchet it up? I dont want to unscrew it if thats possible. thank you

So if all the parts are present the adjuster should only go one way, there’s a lever on a spring that drops down to keep the star wheel from backing off. So they should only adjust tighter, with a “click” after each notch on the star wheel. To go one too tight and back it off you need to pull the lever up like @TrailBeast said.

Tightening the brakes is actually unscrewing the adjuster, you’re making the adjuster longer. If everything is assembled properly and your shoes aren’t smoked you shouldn’t be able to unthread it completely.

The caveat is that the whole assembly has been put together properly. There’s a left and a right, if they’ve been switched they won’t work (or adjust) as they should. And sometimes the lever gets left out, or not set onto the star wheel correctly, etc, etc
 
one of the shoes on the LR was very thin & I did notice left hand threads on the adjuster. I didn't get into the RR drum as one lug was way too tight (gonna need a breaker bar)
 
MC bled/lines bled/front discs tight/rear drums adjusted up slightly (they were pretty close as is) & NO change, any thoughts? RR EDIT they are power & isn't there an adjustable pushrod in that assy?
 
-
Back
Top