I had the drums and rotors on my RR turned down and now they are only .001-.002" over the minimum thickness numbers cast into them. Is it a good idea to use them if they are getting this thin even though they are still within spec? Right now I'm having trouble getting the brake pedal (which is already close to the floor before pressing it down - see my other post here) to activate the brakes without having to press it all the way down to the floor, and I'm wondering if the thinness of the drums and rotors is adding to this problem. I might need to do some more adjusting on my rear shoes to try to remedy this, but you can only move them out so far and then you run out of adjustment. Also, it seems like you are limited in how far the pistons in the calipers can move to push the brake pads out to contact the thinner rotors on the front brakes.
How close is too close?
- Thread starter taguy16
- Start date
69hemibeep
Sponge Bob Square Wheels
Your ok. Make sure the shoes are adjusted out and slightly drag on the drum when you spin them then mash the pedal and see if they still do. Then bleed them if needed
Russ69Runner
Well-Known Member
Do you have power brakes or manual one's. You may have an air bubble in the line some where. Suggest bleeding them. They make a longer rod for the brake master cylinder and an adjustable one. Just some thought's.
droptop
Well-Known Member
As long as you are in spec on thickness you will be good. A worn master cylinder maybe your issue on pedal height.
I replaced the master cylinder with a remanufactured one as well as the proportioning valve with a new brass one because the old valve was leaking. I also replaced all but one of the brake lines with new OEM style steel ones then bled the brakes. I've adjusted the brake shoes once until they were dragging lightly on the drums, but I may need to do it again if I can't get the pedal where I want it to activate the brakes. Are '73 model brakes supposed to be self adjusting as in you can back the car and slam on the brakes to adjust them?
This car has power brakes unfortunately. Maybe Chrysler thought power brakes were needed for this big of a car, but I don't think they are and I wish I would have tried to convert them to manual brakes which I much prefer. I have manual brakes on my old Firebird - which is also a fairly heavy car - and they have a much better feel than the power brakes I've used, and they stop the car just fine. Another advantage of manual brakes is you don't have a big brake booster taking up extra space in the engine compartment (which always seems to be in the way of something or the other).
Right now I'm thinking the brake pedal was supposed to sit lower than the clutch pedal on these cars for some reason because I found a picture of a car similar to mine that was that way, too.
Thanks for the responses.
This car has power brakes unfortunately. Maybe Chrysler thought power brakes were needed for this big of a car, but I don't think they are and I wish I would have tried to convert them to manual brakes which I much prefer. I have manual brakes on my old Firebird - which is also a fairly heavy car - and they have a much better feel than the power brakes I've used, and they stop the car just fine. Another advantage of manual brakes is you don't have a big brake booster taking up extra space in the engine compartment (which always seems to be in the way of something or the other).
Right now I'm thinking the brake pedal was supposed to sit lower than the clutch pedal on these cars for some reason because I found a picture of a car similar to mine that was that way, too.
Thanks for the responses.
69hemibeep
Sponge Bob Square Wheels
Some pedals are uneven but I don't know why, mismatched parts possibly
Russ69Runner
Well-Known Member
Classic show's a clutch rod that is adjustable. That may be the way to go this should help make the pedals even. I agree with you on the power booster on the fire wall those thing's do seem to be in your way when working in the engine bay. That is why I am staying with the manual brakes like you said they stop the car just fine. It sounds like you have done every thing you could do. You know that the master cylinder might need a longer plunger rod from the brake pedal just thinking out of the box.
Like I mentioned in my other post about the low positioned brake pedal, I felt the problem was more the short link that goes from the pedal arm to the pivot at the bottom of the pedal box and not the pushrod that goes into the back of the piston in the master cylinder. The adjustable brake rod kits I've seen just have an adjustable pushrod going into the MC, and therefore I think they are more for cars that don't use the pivot set-up like the later B and and all the E-body Mopars did. (Actually there's a small amount of adjustment in the original upper pushrods, which I tried using, that didn't affect the pedal height any - it's just for taking up any slack between the end of the pushrod and the back of the piston in the MC.) Other than looking high and low for a longer front link the only way I figured there was to make it longer is to add on to this link by welding or brazing in a piece of metal. Alternatively a person could just make one from scratch, somehow, that is longer than the original. The original front link appears to be forged steel, or possibly cast iron.
droptop
Well-Known Member
Just because you have replaced it, don’t rule it out. More and more parts that get “remanufactured” are bad right out of the box.
I think you're right. If I try everything else and still have a lousy brake pedal then I'm going to look into that.
Russ69Runner
Well-Known Member
Rebuilding an old master cylinder is ok sometimes. That is why I bought a new one to go on the runner. Even the brake drum cylinders can be rebuilt I have done it and they work good sometimes then other times they would leak. So just depends on how old they are. They work thousand's of times and do ware out. 
I thought all you could get for old Mopars was reman master cylinders: I think most are being done by Cardone.
I have rebuilt both master cylinders and wheel cylinders myself and the biggest obstacle to success doing this is how pitted they are from having old DOT 3 or 4 brake fluid in them for years and years because DOT 3 and 4 brake fluids absorb moisture from the air and have to be changed regularly - something that almost nobody does. When the bores on these get badly pitted from corrosion they can't be cleaned up with a hone very well and are likely to leak, at least in my experience.
I've dealt with so many brake system problems caused by corrosion over the years that I now use DOT 5 brake fluid exclusively on the cars I work on because it's so much better for metal parts being it's silicone based. IMO it's worth the extra cost and trouble you have to go thru to switch over to it (you have to completely remove any DOT 3 or 4 fluid and they won't mix with the DOT 5 fluid). Also DOT 5 brake fluid won't eat thru paint like DOT 3 or 4 does if you get some on the painted surfaces of your car (which is inevitable). Of course most folks here probably already know this.
I have rebuilt both master cylinders and wheel cylinders myself and the biggest obstacle to success doing this is how pitted they are from having old DOT 3 or 4 brake fluid in them for years and years because DOT 3 and 4 brake fluids absorb moisture from the air and have to be changed regularly - something that almost nobody does. When the bores on these get badly pitted from corrosion they can't be cleaned up with a hone very well and are likely to leak, at least in my experience.
I've dealt with so many brake system problems caused by corrosion over the years that I now use DOT 5 brake fluid exclusively on the cars I work on because it's so much better for metal parts being it's silicone based. IMO it's worth the extra cost and trouble you have to go thru to switch over to it (you have to completely remove any DOT 3 or 4 fluid and they won't mix with the DOT 5 fluid). Also DOT 5 brake fluid won't eat thru paint like DOT 3 or 4 does if you get some on the painted surfaces of your car (which is inevitable). Of course most folks here probably already know this.
droptop
Well-Known Member
For reasons listed about corrosion, I always use new instead of remanufactured on brake parts. These new parts are readily available at most online parts houses. When it comes to brakes, that is one area where you don’t want to try to save a buck.
Russ69Runner
Well-Known Member
I agree with droptop new parts are easy to find for the older mopar's in many brake parts are out their. They are not that expensive. You are rite on with the Dot 5 fluid Taguy16 guy. Motor cycles moved to use this fluid early on like Harley. I like most guys found it was better to replace lines and hard ware on brake system's rather than rebuilding them. After all your life or someone else's is in our hand's. It is one thing to make a car go but stopping has to work above all. This why the auto craft's men have gone to an air craft type braking system like the disc brake. Far better than the old brake drum even though it has worked for a long time and did a pretty good job. Well hope you get your brake pedal length set the way you want. Russ.
69hemibeep
Sponge Bob Square Wheels
Used parts are fine. If the brakes don't stop you something will LOL
Russ69Runner
Well-Known Member
That is a fact!!!!!! 
Roadcuda
Well-Known Member
You know from experience, huh Bob?
droptop
Well-Known Member
Russ69Runner
Well-Known Member
That is pretty bad!!!!!!!
69hemibeep
Sponge Bob Square Wheels
Progressive bought the car and took it away. Well played Harold LOL