pschlosser
Well-Known Member
I've done roofing, in the past, in summer heat. The felt (black tar paper) is brutal to work over. You get heat from the sun above, ambient heat from the air, and lots of heat from below coming from that black tar paper.
73 Soft Pedal Learning Process
- Thread starter Cav73
- Start date
Happy 4th of July everyone. I am just following up.
It took some time to get one of the drums off, but I have now inspected all four wheels and I found no leaks beyond the passenger side caliper. I peeled back the rubber covers on both wheel cylinders in back, on each end. No leaks.
I saw no leaks on the fitting to the wheel cylinders.
Photos here show the inside of the driver side drum and drum cover. All parts are new.
As I said earlier, the wheels did not rotate easily at all, so having bought a new brake spoon, I have loosed the brake drum on each side. This was how I got the driver side drum cover off.
It took some time to get one of the drums off, but I have now inspected all four wheels and I found no leaks beyond the passenger side caliper. I peeled back the rubber covers on both wheel cylinders in back, on each end. No leaks.
I saw no leaks on the fitting to the wheel cylinders.
Photos here show the inside of the driver side drum and drum cover. All parts are new.
As I said earlier, the wheels did not rotate easily at all, so having bought a new brake spoon, I have loosed the brake drum on each side. This was how I got the driver side drum cover off.
Here are photos of the passenger side drum.
I loosened up each drum about 30 clicks. When I remounted the wheels, they are definitely not as tight as they were before. However, I can't give the tire a hard twist and watch it spin freely.
Each side slows down quickly.
Not having worked on drum brakes before, I don't have the feel for this yet. I checked out videos on it though, including one by Uncle Tony's Garage, and it seems like a very loose, near free rear wheel spin is OK for drag racers and burnouts. Not the plan for this car.
That said, I had trouble figuring out:
1. What is the normal start point for adjusting the drums? Is it when they are so loose they spin 100 revs without stopping? Seems like anything that loose might disengage the pads or adjustor wheel or something - but just guessing.
2. How to make sure each wheel spins the same. Well, the rear wheels spin together. It is not like the front where you can get an idea easily of what each is doing and match them after adjusting the first wheel.
Anyway, I think I can adjust the rear wheels further if needed, once I bleed the lines and top off the MC. Hopefully the issue was the leak in the right front caliper fitting or the fluid being low because it was never filled all the way. I found out there is nothing in the power steering pump either, so anything is possible.
I loosened up each drum about 30 clicks. When I remounted the wheels, they are definitely not as tight as they were before. However, I can't give the tire a hard twist and watch it spin freely.
Each side slows down quickly.
Not having worked on drum brakes before, I don't have the feel for this yet. I checked out videos on it though, including one by Uncle Tony's Garage, and it seems like a very loose, near free rear wheel spin is OK for drag racers and burnouts. Not the plan for this car.
That said, I had trouble figuring out:
1. What is the normal start point for adjusting the drums? Is it when they are so loose they spin 100 revs without stopping? Seems like anything that loose might disengage the pads or adjustor wheel or something - but just guessing.
2. How to make sure each wheel spins the same. Well, the rear wheels spin together. It is not like the front where you can get an idea easily of what each is doing and match them after adjusting the first wheel.
Anyway, I think I can adjust the rear wheels further if needed, once I bleed the lines and top off the MC. Hopefully the issue was the leak in the right front caliper fitting or the fluid being low because it was never filled all the way. I found out there is nothing in the power steering pump either, so anything is possible.
I wonder if its the residual valve in the master cylinder disc and drum master cylinders are different I had a problem one time when I added front discs on a all drum car and I removed the residual valve on the side that runs the front brakes then it was fine
Ricks72Chlgr440
Well-Known Member
After you rebuild you adjust each side so you just start to hear the drum dragging. After you put some miles on the car, go back and readjust. You don't want them too tight or they can really drag because of the heat of friction. Just adjust for some drag and do a test drive checking for adequate braking. When all is good, drive it for awhile and come back and readjust. You'll be good for a long time after that.
Challenger RTA
Well-Known Member
I don't know if this will help your sort your problem out.
The E brake is misnomer. It is parking brake first. If it is not used that way it won't work as an E brake in time of need.
That being said. Being in working order, every time it is used it adjust the shoes to the drum. It will be snug and probably rub a little bit that you can hear as you turn the wheel. If it's not adjusted out it will be a soft and not a full pedel.
Then if a wheel cylinder is hanging up. Then again a soft pedal. Every little minus addeds up to a bigger Minus!
Also as MILOJ mentioned. The residual valve not workin will give you a soft panel too. Another minus to add up. It holds 5 to 7 psi in the rear lines. If not it takes a few pumps to expand everything to where it needs to be.
The E brake is misnomer. It is parking brake first. If it is not used that way it won't work as an E brake in time of need.
That being said. Being in working order, every time it is used it adjust the shoes to the drum. It will be snug and probably rub a little bit that you can hear as you turn the wheel. If it's not adjusted out it will be a soft and not a full pedel.
Then if a wheel cylinder is hanging up. Then again a soft pedal. Every little minus addeds up to a bigger Minus!
Also as MILOJ mentioned. The residual valve not workin will give you a soft panel too. Another minus to add up. It holds 5 to 7 psi in the rear lines. If not it takes a few pumps to expand everything to where it needs to be.
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Thanks MILOJ; this car had the disk brakes stock. I am not sure if it had power brakes when made as the original fenders and fender tag were missing. I think I will know more when I get the brakes bled. There was a very minor leak, and the MC was 1 inch down. That did not help.
Thanks Ricks72Chlgr440; I can still back the rears off more, but I already did so quite a bit. They are not as tight as they were initially but they grip and won't spin with light dragging. I am not sure how far I can back off but apparently it would be quite a bit more. I will adjust after I bleed the brakes.
Challenger RTA, I understand on the E-Brake - really a parking brake. I have that loosened up a lot. Cables are new so no corrosion on the adjustor.
Once I bleed the brakes I will adjust again, and see what happens. The wheel cylinders are new so hopefully they aren't sticking. I am not sure how to test - I guess observe with someone else hitting the pedal with the wheels and drums off. Unless that would hurt something.
I adjusted the rear brakes with the drums off, rotating the adjustor wheel while pushing on the metal tab that keeps it from rotating forward and "loosening". I had to go around a couple of times to get the drums as loose as they are now, and they still seem pretty tight. The pads are brand new.
Ricks72Chlgr440
Well-Known Member
Once you get the brakes adjusted so the drum slides on pretty easily, put a flat blade screwdriver (or old school adjusting "spoon" tool) into the access hole on the inside of the brake backing plate. There should be plastic or rubber plugs covering the holes but many cars don't have them anymore. With the drum off you can put the screwdriver in and see where it contacts the star wheel, then put the drum on and click the wheel until rotating the drum produces a slight drag. My cars have a sure grip differential which makes rotating the drum or wheel assembly nearly impossible. I have to click the star wheel until there is some drag putting the drum back on. It is much easier on cars with an open rear end!
pschlosser
Well-Known Member
you can manully adjust if you want.
it looks like there are self adjusting brakes in the rear. adjusting the brakes in the rear is pretty easy, when your braking system is fully functioning. if they are too tight, you must manually loosen them. but when too loose, placing the car in reverse and driving rearward, brake abruptly. this will usually advance the star wheel one notch. keep repeating until they self-adjust to the sweet spot. since backing up is a common activity, they tend to stay adjusted, self-correcting as needed.
it looks like there are self adjusting brakes in the rear. adjusting the brakes in the rear is pretty easy, when your braking system is fully functioning. if they are too tight, you must manually loosen them. but when too loose, placing the car in reverse and driving rearward, brake abruptly. this will usually advance the star wheel one notch. keep repeating until they self-adjust to the sweet spot. since backing up is a common activity, they tend to stay adjusted, self-correcting as needed.
Ricks72Chlgr440
Well-Known Member
In all the cars I've had with drum brakes over the decades, very few self adjusters have worked as they were designed. The one car I had that DID work required me to go pretty fast in reverse then hit the brakes for the adjuster to work properly, as you mentioned. Had to do this several times as well.
Thanks, I think you just nailed the situation I have - my car has a sure grip rear end also. Therefore it will not turn easily - no matter how loose the brakes are. My thought is that this creates an incorrect impression that the brakes are making it difficult to spin the wheels by hand when it is really the differential. I will try your trick with the star wheel/slight drag when putting the drums on, to get the best start point for adjusting.
Also, I have an adjustable rear proportioning valve and I will set that in the middle of the adjustment range.
pschlosser
Well-Known Member
the rear wheels on a sure grip will turn pretty easily with both rear wheels off the ground (i lift at the pumpkin) and the transmission in neutral. not quite as easily as a standard differently, but pretty darn close. that said, in these conditions, both sides may be adding friction.
regarding the self-adjusting not working for some people: maybe I have had good luck, correct parts, and solid installations. but in forty years of driving my various mopars, I've only once had to adjust the rear brakes manually.
Here is an update.
First, this week I was certainly able to turn the rear wheels in neutral with them off the ground, rear axle on jack stands. I had the parking brake adjusted loose and I rotated the adjusting wheel back around 35 - 40 clicks to start. I then took the drums on and off the hubs several times to see if there was any drag against the pads while doing so. I did not have any problems with that. I eventually went back on the adusting wheels 20 - 25 clicks, reinserted the plugs in the backing plates and put the drums and wheels back on.
As of Thursday, I could rotate the rear wheels but it took some moderate muscle to do so. I can't just give them an easy whirl and see them spin free with inertia until they decide to halt.
A friend of mine who has bled brakes before came over Tuesday and we bled all four brakes. The fluid was very low in both MC chambers initially so I had to fill it first (1/4 in below the rim). To do the whole job took about a whole bottle of new fluid (I think it was a pint bottle but I forget the amount). We found air in the right front brake line only. We then topped off the MC. I could not really test the brakes with the engine on until today, as the car was tucked into the back of my garage 90 degrees to the doors and I had to get better dollies to reposition it so I could back it up.
Note - one lesson during the bleeding process was that the rubber gasket inside the MC cover likes to inflate, if that's the word, so that the chamber sections point down into the MC. Installing the cover with gasket pointing down like that, without pushing the rubber back up into the domed sections of the cover, ends up displacing fluid over the rim, making a mess and potentially screwing up the paint.
Today I fired up the car and backed into and out of the garage several times to test the brakes. I adjusted the proportioning valve to the middle of the range (5 out of 10 available turns) for now. The good news is that they work, but they grab close to the floor. Now, this could be a characteristic of power brakes, or a feel thing, given I have never driven an E-body with power brakes. My old 72 had manual drums and you really had to stand on them to slow down. The pedal did not move much.
Here, the pedal is pretty firm before starting the car (but not rock hard). It sits about 3-4 inches off the floor, although I will measure the exact distance this weekend. When I start the car, I am not sure if it repositions itself at all, but on putting my foot on the pedal, it goes down pretty easy and starts to grab around 1 -2 inches from the floor. I know the brakes work because when I got the car moving forward and stomped hard, the car stopped so hard that all the headliner hoops shot forward and one hit my head LOL. No headliner yet, obviously.
Going backwards the car would also stop, but I had to position the seat further forward and push the pedal down near to the floor. Pumping the pedal gave me a bit more grab, but I need to do this some more to get a better picture. I have a pretty steep driveway that drops 200 feet through the woods, so I would prefer to get that picture before backing very far past the garage door, as you might imagine.
I am wondering if there is an adjustment issue with the pedal position. I will be reviewing the manual. Tomorrow I will recheck the MC fluid level and look for leaks at the hose and line fittings all around.
I did read today that on a power brake car, the pedal position can be lower than it would be in a manual brake car. Mine sits a couple of inches below the clutch pedal.
Also, it does not feel all that different from the power brake position in my 2013 Challenger R/T (auto) - that also engages fairly low and is a very easy modulation. But I do not have to go nearly to the floor.
First, this week I was certainly able to turn the rear wheels in neutral with them off the ground, rear axle on jack stands. I had the parking brake adjusted loose and I rotated the adjusting wheel back around 35 - 40 clicks to start. I then took the drums on and off the hubs several times to see if there was any drag against the pads while doing so. I did not have any problems with that. I eventually went back on the adusting wheels 20 - 25 clicks, reinserted the plugs in the backing plates and put the drums and wheels back on.
As of Thursday, I could rotate the rear wheels but it took some moderate muscle to do so. I can't just give them an easy whirl and see them spin free with inertia until they decide to halt.
A friend of mine who has bled brakes before came over Tuesday and we bled all four brakes. The fluid was very low in both MC chambers initially so I had to fill it first (1/4 in below the rim). To do the whole job took about a whole bottle of new fluid (I think it was a pint bottle but I forget the amount). We found air in the right front brake line only. We then topped off the MC. I could not really test the brakes with the engine on until today, as the car was tucked into the back of my garage 90 degrees to the doors and I had to get better dollies to reposition it so I could back it up.
Note - one lesson during the bleeding process was that the rubber gasket inside the MC cover likes to inflate, if that's the word, so that the chamber sections point down into the MC. Installing the cover with gasket pointing down like that, without pushing the rubber back up into the domed sections of the cover, ends up displacing fluid over the rim, making a mess and potentially screwing up the paint.
Today I fired up the car and backed into and out of the garage several times to test the brakes. I adjusted the proportioning valve to the middle of the range (5 out of 10 available turns) for now. The good news is that they work, but they grab close to the floor. Now, this could be a characteristic of power brakes, or a feel thing, given I have never driven an E-body with power brakes. My old 72 had manual drums and you really had to stand on them to slow down. The pedal did not move much.
Here, the pedal is pretty firm before starting the car (but not rock hard). It sits about 3-4 inches off the floor, although I will measure the exact distance this weekend. When I start the car, I am not sure if it repositions itself at all, but on putting my foot on the pedal, it goes down pretty easy and starts to grab around 1 -2 inches from the floor. I know the brakes work because when I got the car moving forward and stomped hard, the car stopped so hard that all the headliner hoops shot forward and one hit my head LOL. No headliner yet, obviously.
Going backwards the car would also stop, but I had to position the seat further forward and push the pedal down near to the floor. Pumping the pedal gave me a bit more grab, but I need to do this some more to get a better picture. I have a pretty steep driveway that drops 200 feet through the woods, so I would prefer to get that picture before backing very far past the garage door, as you might imagine.
I am wondering if there is an adjustment issue with the pedal position. I will be reviewing the manual. Tomorrow I will recheck the MC fluid level and look for leaks at the hose and line fittings all around.
I did read today that on a power brake car, the pedal position can be lower than it would be in a manual brake car. Mine sits a couple of inches below the clutch pedal.
Also, it does not feel all that different from the power brake position in my 2013 Challenger R/T (auto) - that also engages fairly low and is a very easy modulation. But I do not have to go nearly to the floor.
pschlosser
Well-Known Member
unlilke the front tires, I don't beleive the rear tires will never "spin free" because the differential and drive shaft are also turning. I think there will be just too much there for it to continue spinning after you release the wheel giving it a turn.
While bleeding the brakes, I tend to leave the MC cover off, making inspection easy allowing me to top it up as we go. No fuss with the expanding gasket. If it runs dry during bleeding, and sucks air, you pretty much have to start over, bleeding from the farthest to closest wheels.
You say the pedal sits 1-2 inches lower than the clutch? If you pull on the brake pedal, does it move up those 1-2 inches? If not, that may be the normal position for the pedal. But the two pedals sit at pretty much the same height on this car. Maybe there is a 1/4-inch difference, not enough to really notice.
As far as I know, there is NO adjustment to set the height or travel of the brake pedal. I drove a 1970 charger, today, with power brakes, front disk, rear drum. Albeit, it was a b-body, but it was a factory brake setup.
It begins braking and slowing the car after depressing the pedal 15-20% of its travel. When gently braking up to a stop sign, I don't think I get it past the 50% mark. In fact, with the engine running at a stand still, I can press it to that 50% mark and the pedal stops.
if there are differences in the lengths of the push rods (connects the brake pedal shaft to the MC piston) it may be possible you have a shorter one than you're supposed to. But that seems a real long shot.
While bleeding the brakes, I tend to leave the MC cover off, making inspection easy allowing me to top it up as we go. No fuss with the expanding gasket. If it runs dry during bleeding, and sucks air, you pretty much have to start over, bleeding from the farthest to closest wheels.
You say the pedal sits 1-2 inches lower than the clutch? If you pull on the brake pedal, does it move up those 1-2 inches? If not, that may be the normal position for the pedal. But the two pedals sit at pretty much the same height on this car. Maybe there is a 1/4-inch difference, not enough to really notice.
As far as I know, there is NO adjustment to set the height or travel of the brake pedal. I drove a 1970 charger, today, with power brakes, front disk, rear drum. Albeit, it was a b-body, but it was a factory brake setup.
It begins braking and slowing the car after depressing the pedal 15-20% of its travel. When gently braking up to a stop sign, I don't think I get it past the 50% mark. In fact, with the engine running at a stand still, I can press it to that 50% mark and the pedal stops.
if there are differences in the lengths of the push rods (connects the brake pedal shaft to the MC piston) it may be possible you have a shorter one than you're supposed to. But that seems a real long shot.
Thanks! Good info, starting with the MC cover. My thought would be just taking the cover off could let in air but working on a MC is new to me.
I will pull up on the brake pedal and see whether it moves tomorrow.
I am not sure how long the MC push rod is, or if it is adjustable. I really hate to think about taking the MC off to find out. My restorer got the booster brand new from Classic Industries. I am not sure about the MC but it seems new also. He is a long-time car resto guy with a solid reputation so it is hard to imagine how he could have mismatched the MC and booster, but I guess it can happen.
I plan to test the booster following the check procedure I found so I will report on that too.
I will pull up on the brake pedal and see whether it moves tomorrow.
I am not sure how long the MC push rod is, or if it is adjustable. I really hate to think about taking the MC off to find out. My restorer got the booster brand new from Classic Industries. I am not sure about the MC but it seems new also. He is a long-time car resto guy with a solid reputation so it is hard to imagine how he could have mismatched the MC and booster, but I guess it can happen.
I plan to test the booster following the check procedure I found so I will report on that too.
pschlosser
Well-Known Member
The MC sucks from the bottom, so its okay to leave the cover off while bleeding.
Katfish
Well-Known Member
Recheck that Green spring on bottom.
Looks to be in wrong spot on 1 side.
It shouldn't be dragging on the adjuster.
Looks to be in wrong spot on 1 side.
It shouldn't be dragging on the adjuster.
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