First time having manual brakes, are mine bad?

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mbaird said:
Entirely possible the the MC has been replaced with the wrong one over the years. I have manual drums on my 69 Swinger but I changed up the MC and wheel cylinders for more stopping power ( easier pedal) and it works great!
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That’s a good point. Which MC did you go with?
 
standup303 said:
But at this point I have no idea why someone would want manual brakes
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"The parts you don't add don't cause you no trouble" C. C. Nance

Simplicity, plain and true!

My 67 Dart 273 2bbl has manual front disc read drum.

I'm 60 and have driven manual brakes in the past. When I got my dart 5 years ago I hadn't driven a manual brake (or manual steering for that matter) in 30 years. At first it felt odd but now it is no problem to switch back and forth between the two.

The reason I asked your age is if you are young enough maybe even 40 to 50 you may have never driven a manual brake car and are too used to the power brake feel. I imagine if you are young enough you may never have driven a carborated engine either. It takes a couple of pumps and a good deal of cranking to start them if sitting for a while, just the nature of the beast.
 
late to the party but money is on the wrong master. Betting someone installed a 1 3/32" or 1 1/8"
Find a 1" or 15/16" and you'll be happy
 
RustyRatRod said:
That doesn't sound normal. Tell us about you. Are you a small guy or girl with not a lot of lower body strength? No disrespect meant, I'm just askin as I caint see you. We need to make sure it IS the car, after all. Generally speaking, these old cars stop reasonably well. My 64 Valiant for example has the aforementioned 9" manual drums all around and it stops VERY well for what it is. My wife even likes it. I think from your description though, it does sound like something is wrong with the car itself. But if you're only like 5' 4" and 110 pounds, that could have an effect too.
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What's next his ***** size?.. LOL..:rolleyes:...
 
1st ! upgrade the master cyl. this will save you lots of money,time,effort. go bigger(volume) bore and possibly metering block changes to match your set up.
 
Started working on these, the passenger side front bleed port was clogged. My guess is the brakes have not been bled in a long time. Fluid was rust colored. Just waiting on some more freer time to finish replacing the hoses which had some small cracks and then wrap up. But with my initial bleed the pedal felt night and day better!
 
Do you have a proportional valve if I remember correctly you need one for front disc/ drum rear
 
standup303 said:
Started working on these, the passenger side front bleed port was clogged. My guess is the brakes have not been bled in a long time. Fluid was rust colored. Just waiting on some more freer time to finish replacing the hoses which had some small cracks and then wrap up. But with my initial bleed the pedal felt night and day better!
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"It may just be" that conditions of the entire brake system are worse than you think. Cylinders could be rusted/ corroded/ stuck. Hoses and tubing could be blocked. I would tear down all 4 corners and inspect with the expectation that you are going to need to replace something. Flush all lines and hoses and SERIOUSLY consider replacing the hoses.
 
67Dart273 said:
"It may just be" that conditions of the entire brake system are worse than you think. Cylinders could be rusted/ corroded/ stuck. Hoses and tubing could be blocked. I would tear down all 4 corners and inspect with the expectation that you are going to need to replace something. Flush all lines and hoses and SERIOUSLY consider replacing the hoses.
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standup303 said:
I am replacing all hoses. Not the lines though.
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Make sure you inspect the whole length of all the lines. They rust, and if your fluid is rust colored some of that may be from the lines. The other thing is that they do get pinched sometimes too, people put jacks and jack stands in dumb places and if the lines are original there's been lots of opportunities for them to get damaged in that time.

If on inspection they look ok they're probably fine, but, you don't just want to assume they're ok.
 
I love manual brakes on older cars. I have manual brakes on most my classic cars including our '77 van. It's one conversion I always try to do. Yes, it takes a little more "leg", but by all means, you shouldn't be standing on the pedal. My wife can drive any of our cars and stop them on a dime. But for sure, manual brakes have a different feel than power brakes.
 
standup303 said:
I just got my Dart and it is the first vehicle I have driven with manual brakes. Disc front, drum rear. I have to stand on the brake pedal, hard, just to come to a complete stop. Does that seem normal? I am ordering drilled slotted rotors for the front, new pads, then new shoes for the rear. Going to give them a good bleed and go from there. But at this point I have no idea why someone would want manual brakes!
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One thing to check is the master cylinder bore diameter. Drum brake cars had smaller diameter wheel cylinders which required less fluid as the pistons traveled. This required a smaller diameter master cylinder to develop the necessary braking force. The disc brake caliper cylinders are larger diameter and take more fluid to clamp the disc. The master cylinders with the same bore as drum brakes would require longer travel to get braking pressure. The answer to the long travel was power assist by vaccum booster, and a larger diameter master cylinder to get the required pressure. If someone in the past has asked a parts store for a disc brake master cylinder and bolted it in, you will have the situation you describe. How is pedal travel? A disc brake without booster should have an intermediate diameter between the manual drum and power disc cylinders. Remember that these model years were when disc brakes were being introduced along with power assist, so many parts were changed.
Another point, where the brake lines thread into the master cylinder there are residual valves. On drum brakes these hold about 10PSI in the lines to ensure no air can get in. Drum brakes have heavy return springs so the 10PSI can not hold the shoes on the drum. Discs use runout or the squ
are piston seals to retract the pistons slightly, so only 2PSI residual valves are used. All drum vehicles will use two 10# residual valves, 4 wheel discs use two 2# residual valves while disc/drum cars use one of each.
Dealing with parts counters these days is a trip to the lounge for a couple of whiskys experience. Even the old dogs behind the counter have a rough time because the old parts books have been swept away for a glowing box full of stupidity. In those books was a wealth of information where you could quickly check master cylinder diameters for example and compare. The glowing box requires make, model, year, engine and probably transmission, rear axle size and I usually tell them the color. They may require the date your wife washed your underwear by now. To find out about different cylinder diameters is near impossible. Closest you get is drum or disc brakes. The concept of manual discs is beyond their comprehension, but they were manufactured and require a different master cylinder.
 
1WildRT said:
Seems to me starting with the change to single piston disc brakes in 73 Mopar added a booster so manual brakes either point to added discs or removed booster... Either way the M/C bore size becomes a question...
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mvh said:
You really need to break in the new disc pads properly to avoid glazing. They aren't just "throw them in and go". Yours could be glazed, or a caliper piston could be frozen.

I have two K-H disc A-bodies, both with manual brakes. One has the 1-1/32" and the other has the 15/16" MC. There is a difference in pedal effort, but there isn't a difference in stopping power. Both also have slotted cross-drilled rotors, but that is because I like to take them on winding roads up in the Sierra and Siskiyous. Not really needed for a cruiser. They don't affect normal stops, they just help dissipate heat when you are really hitting the brakes hard over a period of time, like a track day or a 9% grade.
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What are the caliper piston diameters? Between the two vehicles there may be a difference in the caliper bores which also then dictates the MC bore change. The brake system balance is a complex issue that includes the ratio between MC and wheel cylinder/caliper bores and pedal ratio to develop the required braking force. The designers need to take into account drivers of 5' and 100# stature to 6'5" and 300# stature. The 5' driver has to be able to reach the pedals and develop enough braking force relatively easily. For the 6'5" 300# driver, pressing on the pedal with enough force is likely not a problem. Squeezing into the seat for them can be the difficulty.
 
67Dart273 said:
Might also be the pads are poor material and glazed. "The basics." Rear drums: Make sure of hte usual, good parts, not all rusted/ bound up, adjusted, good shoe material AND IF THE drums have been turned out too much, they are now LARGER and without "arcing" the shoes to fit, only contact the shoe "middle" of the lining. This does two things: Because it's working on a fraction of the shoe surface, it overheats and glazes the lining, and because there is no surface, it just doesn't have much stopping force.

Also I would not get too excited about slotted rotors. Get some good pads if not, and have the factory ones turned.

My 67 when I had it together, I "threw it together" (to see if it would work, with the factory drum master. Worked find. I had 73/ 74 front disc, and Ford Versailles rear disk. You did have to press it some, but you could lock it up or nearly so at freeway speed. It REALLY stopped.
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What MC did you use when you converted to 4 wheel discs?
 
Dale Davies said:
One thing to check is the master cylinder bore diameter. Drum brake cars had smaller diameter wheel cylinders which required less fluid as the pistons traveled. This required a smaller diameter master cylinder to develop the necessary braking force. The disc brake caliper cylinders are larger diameter and take more fluid to clamp the disc. The master cylinders with the same bore as drum brakes would require longer travel to get braking pressure. The answer to the long travel was power assist by vaccum booster, and a larger diameter master cylinder to get the required pressure. If someone in the past has asked a parts store for a disc brake master cylinder and bolted it in, you will have the situation you describe. How is pedal travel? A disc brake without booster should have an intermediate diameter between the manual drum and power disc cylinders. Remember that these model years were when disc brakes were being introduced along with power assist, so many parts were changed.
Another point, where the brake lines thread into the master cylinder there are residual valves. On drum brakes these hold about 10PSI in the lines to ensure no air can get in. Drum brakes have heavy return springs so the 10PSI can not hold the shoes on the drum. Discs use runout or the squ
are piston seals to retract the pistons slightly, so only 2PSI residual valves are used. All drum vehicles will use two 10# residual valves, 4 wheel discs use two 2# residual valves while disc/drum cars use one of each.
Dealing with parts counters these days is a trip to the lounge for a couple of whiskys experience. Even the old dogs behind the counter have a rough time because the old parts books have been swept away for a glowing box full of stupidity. In those books was a wealth of information where you could quickly check master cylinder diameters for example and compare. The glowing box requires make, model, year, engine and probably transmission, rear axle size and I usually tell them the color. They may require the date your wife washed your underwear by now. To find out about different cylinder diameters is near impossible. Closest you get is drum or disc brakes. The concept of manual discs is beyond their comprehension, but they were manufactured and require a different master cylinder.
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So let's get theory and reality lined up here. There were only 3 different sized master cylinder bores for A-bodies from '67-76- 15/16", 1", and 1-1/32". That's it.

Stock A-body master cylinders were 15/16" for 9" drums, 1-1/32" for 10" drums, 1-1/32" for manual single piston (73+) disks, 15/16" for power 73+ disks, and 1" for the KH disks. From the '73 service manual, "L" is the A-body designation. The 2.75" calipers were B/E/R/F/M/J body fare, pin style in '73 hence the "floating" designation, the 2.6's were A-body single piston slider calipers. Since this chart is from a '73 manual it doesn't include the '76 A-body 2.75" piston sliders, but they used the same MC as the 2.6" calipers on A-bodies anyway.
screen-shot-2016-08-18-at-4-01-07-pm-png.png

From the '70 service manual, for the fixed caliper KH's used on A's
screen-shot-2016-08-18-at-4-12-22-pm-png.png


As you can see, A-bodies are actually backward when it comes to manual and power disk master cylinder bore sizing. That's because the power booster linkage changes the pedal ratio. So the power disk cars actually got a smaller bore master cylinder than the manual disk cars.

I like the 15/16" bore for manual disks. I actually think the 15/16" master cylinder improves your brake modulation capabilities quite a bit with the slightly longer travel, but it still provides the max line pressure. And the travel is not "too long", there's still plenty of space before the pedal gets anywhere near the floor.

Dale Davies said:
So what residual pressure do you have in your 4 wheel discs?
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None is required. The head pressure from the height of the master cylinder is enough. If it were an early truck with the master cylinder under the floor or something you'd need the 2 psi residual. Most disk master cylinders don't have any residual at all, they have to be added.
 
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I had a Ford truck with that situation. That turnout to be rusted/frozen pads in the calipers that no longer moved. But I guess you would know that since you had it apart.

A lot of good input. I would say don’t forget frozen caliper pistons. Remove the caliper Have someone step on the peddle slowly and watch the pistons moved. See if you noticed pitted bottom edges on the calipers. If you can pull away the boot to check even better. You can always push them back in with a C clamp.

Rust in the MC bore. When you open the bleeder screws it should shoot out.

Worse case reading the others is frozen MC or possibly a bad proportionating valve if you have one. They come apart and are supposed to indicate loss of brakes with the use of the a plunger that moves. Especially for a car that sat a long time. Trace your brake light cable to find it.

Different input. Good luck
 
mikess68 said:
1st ! upgrade the master cyl. this will save you lots of money,time,effort. go bigger(volume) bore and possibly metering block changes to match your set up.
Click to expand...

Bigger bore diameter makes the pedal effort harder . Smaller 15/16 decreases the effort but the pedal travels further which I like . Smaller bore creates more PSI .

Bigger bore on the wheel cilynder makes more power
 
My 78 LRT was hard to push the peddle even with a new Power Booster. I replaced all rubber hoses. I replaced the calipers and wheel cylindes. Was the same.

Pulled the RUSTED brake peddle out, cleaned the pivot pin and the bushing and smooth as silk.
 
Finally finished up the brakes yesterday and they literally few the same as before. Pretty bummed about it. Here’s the specs. Any help would be appreciated. About to bring the car to a shop to make sure I’m not missing something. Pedal is hard and the stopping power is down right dangerous for road use in my opinion.

All brand spanking new:
Aluminum master cylinder
Full inline tube line kit
Stainless hoses front and rear
Seals replaced on 2 front calipers
Semi metallic pads front
Drilled slotted power stop rotors front
Shoes and hardware rear
DOT 5 fluid
No bubbles on bleed
 
standup303 said:
Finally finished up the brakes yesterday and they literally few the same as before. Pretty bummed about it. Here’s the specs. Any help would be appreciated. About to bring the car to a shop to make sure I’m not missing something. Pedal is hard and the stopping power is down right dangerous for road use in my opinion.

All brand spanking new:
Aluminum master cylinder
Full inline tube line kit
Stainless hoses front and rear
Seals replaced on 2 front calipers
Semi metallic pads front
Drilled slotted power stop rotors front
Shoes and hardware rear
DOT 5 fluid
No bubbles on bleed
Click to expand...

What is the bore diameter of the master cylinder?
 
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