Poor Brakes on my '64

Hello all,
Been awhile since I've been on here! As some of you may remember, I have a '64 Polara that was pretty much a basket case when I got it. Most of the big issues have been worked out for now, but the one I'm having a hell of a time figuring out is the brakes.

Here's the scoop. It's got manual four wheel drum brakes. The master cylinder has been converted from the original single pot style to the dual chamber style. Every part is brand new. The issue is, the car doesn't stop for crap. I'm not saying it takes 500 feet to go from 80-0 mph. I'm saying it takes 5 miles to come to a stop. The pedal is firm as rock, but seems to "grab" low (about mid travel). Here's what's been done so far:

- As stated before, new master(s). Initially I tried a MC from a '76 Dart that also has four wheel manual drum brakes. Pedal grabbed low. Currently have a master on it from a late 60's Monaco or Charger on it. No change. This swap was done to test and see if different bore sizes (15/16" vs 1") would affect it. Both masters feel identical in the car.

- New brake lines front to rear. Line off front of resivoir goes straight to the rear brakes. Line off the rear resivoir goes to a junction block that splits to go to the front brakes. All brake lines on the car are 3/16" diameter.

- New wheel cylinders, shoes and hardware (including adjusters!) at all four corners. New drums in the back. Front drums were turned so there's no ridges in them. Shoes are oriented properly withing the drums as well. All brakes have been adjusted up to the point they *just* touch the drums and lightly drag while rotating. For shits and grins I have also run the shoes tight up to the drums and pressed the pedal. You guessed it, no change.

- I have bled the brakes three or four times at least. I always start by gravity bleeding them, then doing the two man bleeding procedure. The fluid streams at the rear of the car aren't as strong as I'd expect them to be (weaker than the front anyway). They just kind of dribble or lightly squirt when the bleeder is cracked. I am running new DOT3 fluid.

- I have tried lengthening and shortening the brake push rod to see if that changes anything, but it doesn't.

The pedal *grabs* at about half stroke. At that point it becomes solid as a rock or dang close. When driving down the road if I slam on the brakes it will not lock any of the wheels, no matter what speed I'm at. Even on gravel, it will not lock the wheels up. When the car does finally stop, it stops surpringly straight about 75% of the time.

I'm not new to Mopars or drum brakes at all. My first Mopar ('76 Dart) had four wheel manual drum brakes. That pedal was high and very firm. That car had no problem stopping at all! I also had a '72 D150 with four wheel power drum brakes. It also stopped pretty well.

So I'm a bit stumped here. Do I need a proportioning valve? A large parachute? A different master? I'm out of ideas!

If you are using a dual well master but still have the original single well proportioning valve Id say that might be the issue.

What kind of pressure at the rear junction lines, at & after the ‘y’? Bleeder squirts oughta be the same, as I’m sure you know.

I'm useing a MC from a '71-'73 Dart. 15/16" bore. Also just a conversion block.

I have not yet hooked up a pressure gauge to any of the ports, but the rear brake pressure seems to be a lot less than the front (just by eyeballing the squirts while bleeding them).

I like the look of that junction block. Certainly keeps everything nice and clean! My setup is identical to that, just without that exact block.

Dave145 said:

I have not yet hooked up a pressure gauge to any of the ports, but the rear brake pressure seems to be a lot less than the front (just by eyeballing the squirts while bleeding them).

I like the look of that junction block. Certainly keeps everything nice and clean! My setup is identical to that, just without that exact block.

Click to expand...

I saw a way around the block somewhere when converting from a single to a dual MC. Probably what you did and I'm thinking it's ok.

Did you buy new brake shoes from NAPA or any parts house? The new lining of today is not the same as what was on the car when new. It's a bit softer and takes awhile to break in. Even when doing a brake job years ago it would take awhile for new shoes to seat in. I know my brakes didn't really start to come in good until a couple of hundred miles and I had a set of new old stock on the fronts. Breaking in a set is done with normal use and not over useing them. Over doing it will cause glazing and that's not good.

You have a 3600 lb car with drums front and back and they don't stop anywhere near as well as the cars of today. Back then you learned to keep your distance and be a defensive driver. Just giving you the low down as to how they are and not to expect what you might be used to with the newer cars of today.

Now with that said, can you get them working better? I'll say yes to what you have stated you're having problems with.

If you check your brake pedal rod, do you have a little play between the rod and MC piston? You don't want it tight where it already has the piston started into the bore too far.

You stated you have all new lines. Does that include the rear brake hose that's bolted to the rear end housing? A used hose could be collapsed on the inside even though it looks good on the outside, that's a restriction.

What size wheel cylinders are you useing? 15/16" is the norm.

The 15/16" Master cylinder is preferred for the four drum set-up.

Bleeding procedure: right rear, left rear, right front, left front. You do the farthest wheel from the MC first and work your way back to the closest wheel to the MC.

Bench bleeding a MC is important before installing. Holding the MC in a vice, having lines attached to the ports to recycle the fluid into the reservoirs, you slowly push the piston all the way in until it bottoms out. One slow stroke at a time until there's no air coming out. Some try to do this in the car and it won't work. The brake pedal won't bottom out the piston and air will remain trapped. Not bottoming out the piston when bench bleeding will have the same results. Plug the MC ports with plastic fittings supplied in the bleeding kit when installing the MC to the firewall.

Sounds like you have the shoes and hardware installed correctly. Long shoe lining to the rear?

I saw a way around the block somewhere when converting from a single to a dual MC. Probably what you did and I'm thinking it's ok.

- If the block works the way I think it does, I'm pretty sure they do the same thing. One just looks prettier!

Did you buy new brake shoes from NAPA or any parts house? The new lining of today is not the same as what was on the car when new. It's a bit softer and takes awhile to break in. Even when doing a brake job years ago it would take awhile for new shoes to seat in. I know my brakes didn't really start to come in good until a couple of hundred miles and I had a set of new old stock on the fronts. Breaking in a set is done with normal use and not over useing them. Over doing it will cause glazing and that's not good.

- I bought the raybestos shoes for it from NAPA a couple years back when I first got the car. I've put close to 8,000 or so miles on it since I bought it and I don't usually beat on it too much.

You have a 3600 lb car with drums front and back and they don't stop anywhere near as well as the cars of today. Back then you learned to keep your distance and be a defensive driver. Just giving you the low down as to how they are and not to expect what you might be used to with the newer cars of today.

Yeah that I'm factoring in with all this as well. I've just personally had cars with four wheel drum brakes that stop better than this one, hence my questioning of this car's performance. I wish the DOT would start making people be defensive drivers again. Damn folks on their phones cutting people off is ridiculous.

Now with that said, can you get them working better? I'll say yes to what you have stated you're having problems with.

- I hope so!

If you check your brake pedal rod, do you have a little play between the rod and MC piston? You don't want it tight where it already has the piston started into the bore too far.

- From what I can tell, it seems like the rod kind of "clicks" into the master bore. When I tried lengthening it a touch, there was no change in performance or pedal feel.

You stated you have all new lines. Does that include the rear brake hose that's bolted to the rear end housing? A used hose could be collapsed on the inside even though it looks good on the outside, that's a restriction.

- Yes indeed! All hard and soft lines were replaced with Raybestos hoses when I redid the brake system a couple years ago. The original hose was brittle as could be in the outside and was bulging pretty bad when I got the car.

What size wheel cylinders are you useing? 15/16" is the norm.

I'm pretty sure 15/16". I bought whatever the car was supposed to come with. I don't quite remember what size they were. Granted, a parts catalog has been wrong more than once on this car...

The 15/16" Master cylinder is preferred for the four drum set-up.

I will double check and see what I'm running. I want to say the Monaco/charger MC I'm running is 15/16".

Bleeding procedure: right rear, left rear, right front, left front. You do the farthest wheel from the MC first and work your way back to the closest wheel to the MC.

- That is correct and exactly how I do it both when gravity bleeding and manually bleeding.

Bench bleeding a MC is important before installing. Holding the MC in a vice, having lines attached to the ports to recycle the fluid into the reservoirs, you slowly push the piston all the way in until it bottoms out. One slow stroke at a time until there's no air coming out. Some try to do this in the car and it won't work. The brake pedal won't bottom out the piston and air will remain trapped. Not bottoming out the piston when bench bleeding will have the same results. Plug the MC ports with plastic fittings supplied in the bleeding kit when installing the MC to the firewall.

- Usually I place mine against the wall on my work bench and use some socket extensions to cycle the piston in and out.ive tried the method with the lines going into the resvoirs and the method the MC manufacturer recommends (plugging the holes and then stroking it), and never really saw much of a difference. I do prefer to use the lines because it just makes more sense to me. But yes, I make sure to gently bottom the piston in the bore until it stops making bubbles.

Sounds like you have the shoes and hardware installed correctly. Long shoe lining to the rear?

- Yes. The long shoe linings go to the rear. I forgot to put that in my initial post.

It seems we are in the same thought line with this so far and have all the bases covered. How does your pedal feel? Does it "grab" high? Or does it "grab" somewhere in the middle of it's stroke? How does the car stop? With my car on stands, if I put it in gear I almost need two feet on the brake pedal to get the rear wheel to stop turning.

Dave145 said:

With my car on stands, if I put it in gear I almost need two feet on the brake pedal to get the rear wheel to stop turning.

Click to expand...

That part isn't normal. If you plan on getting or useing a pressure guage, you can start at each wheel cylinder and work your way back to the MC until you find the "restriction". I think that's where you are at on this. Visually check your lines for any kinks. Keep us posted.

I think you have a friction problem. Can you find a shop that can grind your linings to match the radius of your drums? I did this on every brake job I did when working in a dealership back in the early 70's (before asbestos was known to cause cancer)! Always had good brakes. A different lining material also may solve your troubles.
My daily (summer time driver) is a 65 Coronet with 4 wheel drum brakes and I can lock em up with enough pedal force.
Mike

I did a brake job on my 64 Fury, and it doesn't seem to stop as well as it did with the old brakes. I think the newer non asbestos linings dont work as well in the drum brakes...

If you pull your rear drum off you can see how much of the shoe is hitting the drum. That will tell you a big story. If the shoes have not been cut to the drum or fitted you my not be using the brake shoes completely. I have seen up to 1/4 shoes not being used because of the arch in the brake shoes causing poor brakes. But I would in your case look for a blockage. Just 2 cents worth.

I think you still have air. From personal experience I've found that when changing components from stock it is more difficult to achieve the desired results.
1. Have you tried to bleed the front of the master by cracking the line right at the master? If you still have no pressure at that point there is no reason to look down the line for issues. You should have excellent pressure at both ports at the master. Does that master have a built in hold off or metering device to reduce pressure to the rears. Perhaps a Raybestos tech line can answer that.
Your lines going down to the block have that big loop in them. Your only gravity and 2 person bleeding which often does not move enough fluid volume to purge air. You may need to track down a shop that has and old style pressure pot bleeder to clear the air from the lines. The internet also sells reverse bleeding pumps , you force fluid from the rear wheel cylinders back you to the master which pushes the air out. I've used this procedure, its works well but can be messy.
Like other members brought up bench bleeding until both ports create more pressure that you can suppress with you finger while pushing the piston is a must.
I've also elevated the front of the car while bleeding the master (on car) to bring any air closer to the brake line connection.
What you describe when the pedal travels half way then firms up is what can happen when you are losing half the pressure from the master from air.
Good luck

I will pick up a pressure gauge next week and report back. At this point it seems like the next logical step.

I have never heard of having shoes ground to fit the drums. Certainly makes sense though! I will pull the rear drums as soon as it's a bit warmer out and check that out.

I am also considering picking up a vacuum bleeder so I can bleed the brakes that way. It's more convenient and certainly couldn't hurt!

Here is a pic of the MC set up in my 64 when I converted it to manual disc brakes.

There are still high quality brake shoes out there and you shouldn't have a problem locking up the wheels even if the shoes are not a perfect fit to the drums! Have you replaced the wheel cylinders too and with the same size? Didn't see anything about them but I did read over things kinda quickly. If the wheel cylinders are the same size as they were with the old MC that had a larger bore, you will get a bit more pedal travel but the small bore MC will/can give more PSI for the same pedal effort. Does the car have 11" drums or 10's? Either way, make sure the shoes fit the drums like already mentioned.

https://www.google.com/search?client=firefox-b-1-d&q=best+drum+brake+shoes

Yes the cylinders have been replaced. I am 99% sure they are the 15/16" bore cylinders. If memory serves me right (I will go out and measure in a few minutes), I think I have 10" brakes all the way around.

Dave145 said:

Yes the cylinders have been replaced. I am 99% sure they are the 15/16" bore cylinders. If memory serves me right (I will go out and measure in a few minutes), I think I have 10" brakes all the way around.

Click to expand...

Dave.
I've gone through the same problem with my '65 Coronet with drums all around. I recently took off the drums and found that they were glazing. Was it the new material stuff or just air in the system? I don't know but I decided to go back to the original organic shoes to see if there was a difference. I am going to take the car out soon to break them in and test and then I'll get back to y'all.

If you cannot find nos brake shoes the drums will glaze and it will never stop.
This is my personal experience.

My 64, all new brakes, stopped great then not at all.
Pulled the drums, took some rough sandpaper and sanded at an angle one direction, then the other.
Put it back together and it stopped fine, for a few days.

Musclecar Brakes makes a good set for 65 and up, I contacted them to see what the difference was between 64 and 65, never heard back.

An old school guy I know bought out a closed parts store eons ago.
Car stops no problemo now.

Matthon.

matthon said:

If you cannot find nos brake shoes the drums will glaze and it will never stop.
This is my personal experience.

My 64, all new brakes, stopped great then not at all.
Pulled the drums, took some rough sandpaper and sanded at an angle one direction, then the other.
Put it back together and it stopped fine, for a few days.

Musclecar Brakes makes a good set for 65 and up, I contacted them to see what the difference was between 64 and 65, never heard back.

An old school guy I know bought out a closed parts store eons ago.
Car stops no problemo now.

Click to expand...

Matthon
Are you saying now that the car stops good because of a set of old school organic brake linings installed?

I bought new organic brake shoes, they sucked.
I found pics I took, the nos ones are Raybestos, the box states asbestos free, but not sure if they are organic or not. My guess is semi-metallic.

The last pic are semi-metallic I bought from summit which are for a 65. Similar, but not the same, specifically the upper spring hole isn't round, and it's not as far back.
I tried those on the front, and with a different spring one side worked, and the other side would not no matter what I tried.
Wasn't sure if the 65 backing plates are different from 64, I was going to order a 65 spring/hardware kit, then I found the nos shoes.