I did a search and couldn't find anything about the question and problem that I'm having. When you buy a new set of cast iron drums and have the hubs swedged on the drums I know that you have to have the drums turned to get them trued up again. I have had this done and when I tried to install them the drums went over the brake shoes ok but the emergency brake shoes were too tight to allow the drums to turn and the new drums to be installed correctly. I removed the emergency brake, and the new drums would fit the way they should and turn freely. Should I have had the emergency brake drum turned when I had the drums done.
Cast Iron Rear brake drums
- Thread starter Grumps
- Start date
The reason you turn the new drums after installing them on the hub is to make sure that the circle of the drums is concentric to the axis of rotation, so you don't get pulsing of the brakes. Since you don't move the car with the emergency brake set, there is no need to turn the emergency brake surface.
What you describe is very typical - binding on the emergency brake shoes when installing the drums. Back off on the adjustment, and you may need to "persuade" the hub/drum on when you install it. Once it's installed all the way and lined up square on the tapered axle it should rotate freely.
Don't forget to have your service brake shoes arc-ed to the new diameter of the drum (after turning).
JayJay
What you describe is very typical - binding on the emergency brake shoes when installing the drums. Back off on the adjustment, and you may need to "persuade" the hub/drum on when you install it. Once it's installed all the way and lined up square on the tapered axle it should rotate freely.
Don't forget to have your service brake shoes arc-ed to the new diameter of the drum (after turning).
JayJay
Sometimes, ebrake linings are supplied in the wrong thickness .............. especially since some of the linings now come from China. They are supposed to be 5/32" thick but often tend to be closer to 3/16" thick. This might work with old drums but not so much with new cast iron drums. Also, if these are original ebrake bands that have been relined, any slight bend that exists on the band or anyplace in its circumference where the new lining is not tight against the band will cause high spots. The other thing to look out for is ebrake housings that are bent or twisted at the 3" anchor pad where the open part of the circle on the band rides.
Grumps,
Just installed new drums on our '30 coupe. I slipped the rear drums on before taking them in to be swedged fearing the same problem you have. Fortunately they went on easily over the e brake and functions perfectly now that the brakes are done. This was with existing linings. Dale
Just installed new drums on our '30 coupe. I slipped the rear drums on before taking them in to be swedged fearing the same problem you have. Fortunately they went on easily over the e brake and functions perfectly now that the brakes are done. This was with existing linings. Dale
I sanded and filed the e-brake and got the new drums on and everything seems to be working as it should. I took Sweet Pea (what I named her) out for a ride yesterday and the brakes are working fine. I have had quite a few old cars throughout my 74 yrs. but I get more thumbs ups and waves with this one than any other.
rotorwrench
Well-known member
Mel & Randy Gross have had threads testifying to their new drum fitting and shoe fitting services for a long time. This link is a testament to that.
https://fordbarn.com/forum/showthread.php?t=192428
https://fordbarn.com/forum/showthread.php?t=192428
Diastole
Senior Member
Please Help.
I'm new to Model A's, converted from late 50's GM. I bought an oval speedo 1930 Coupe 6 months ago. Car was in good condition. The gentleman that passed took care of her. Brakes however were bad.
With help of my local club and Ford Barn we have rebuilt the brakes. And, I forked out $$$ and bought new rear assemblies from Randy Gross. (new backing plates, springs, shoes, pads, levers, bearings, CI drums, hubs, the whole works). Saving my money for front assemblies. Craftsmanship is excellent. Service after the sale has been great.
I have had help from my local club members, too. Even had a "service day" about my brakes at the club. And, that is where I need FordBarn's help.
The drums were not able to be installed. Too much friction. Called RG and he said sand down the pads a bit. We finally got drums installed. But they only freely spin 320 degrees. The stick with friction the last 40 degrees. RG said, "Drive the car. The pads are soft, they will wear in".
Well that was 2 months ago. RG has said he will "do whatever is necessary to make it right".
I have a bunch of senior model A'ers scratching their heads. The club prez has advised me to post this on FordBarn, read responses, take notes, and call RG. “We have never seen this with new assemblies”.
The rear brakes have been fully rebuilt. The brake pedal has no play, bushings new and reamed. Cross shaft has new bushings and has no play. All lever pins are snug. Clevis pin holes have been welded and redrilled and reamed to accept small pins. Brake rods are 50 1/2" and straight.
The problem is rear brakes cannot be adjusted and the high spot on turning the wheels persists as a problem.
In adjusting:
The rods are adjusted to the max where the threads of the rods require to be bottomed-out against the clevis pins. Otherwise, no braking action.
Using the correctly calibrated brake-pedal-tool the rears can be set to "snug", "tight", and "locked up" while on jack stands, as long as you stay away from the high spots on the hubs. But, on the road this does not manifest as good braking. The adjustment wedge has been advanced quite a lot.Per club members,m “more than should be needed”.
On the road adjusting requires so much adjusting of the wedge, the wheels will not freely turn with no pedal pressure.
Similar problem with emergency brakes.
The whole assemblies have been removed by club members, adjustment shafts measured and changed, pad thickness measured, adjustment wedges changed, etc.
Both rear assemblies have the same sticking problem for about the same ° of rotation. Axles are not bent. Bearings are new and greased. Shims not needed. Nut torqued to 125 ft-lbs. Anti Rattle springs and brake pedal return springs are new.
Please advise. Has anyone seen this with new assemblies?
Plan to call RG after I get a bivy of responses. My club and I are stumped.
Will
I'm new to Model A's, converted from late 50's GM. I bought an oval speedo 1930 Coupe 6 months ago. Car was in good condition. The gentleman that passed took care of her. Brakes however were bad.
With help of my local club and Ford Barn we have rebuilt the brakes. And, I forked out $$$ and bought new rear assemblies from Randy Gross. (new backing plates, springs, shoes, pads, levers, bearings, CI drums, hubs, the whole works). Saving my money for front assemblies. Craftsmanship is excellent. Service after the sale has been great.
I have had help from my local club members, too. Even had a "service day" about my brakes at the club. And, that is where I need FordBarn's help.
The drums were not able to be installed. Too much friction. Called RG and he said sand down the pads a bit. We finally got drums installed. But they only freely spin 320 degrees. The stick with friction the last 40 degrees. RG said, "Drive the car. The pads are soft, they will wear in".
Well that was 2 months ago. RG has said he will "do whatever is necessary to make it right".
I have a bunch of senior model A'ers scratching their heads. The club prez has advised me to post this on FordBarn, read responses, take notes, and call RG. “We have never seen this with new assemblies”.
The rear brakes have been fully rebuilt. The brake pedal has no play, bushings new and reamed. Cross shaft has new bushings and has no play. All lever pins are snug. Clevis pin holes have been welded and redrilled and reamed to accept small pins. Brake rods are 50 1/2" and straight.
The problem is rear brakes cannot be adjusted and the high spot on turning the wheels persists as a problem.
In adjusting:
The rods are adjusted to the max where the threads of the rods require to be bottomed-out against the clevis pins. Otherwise, no braking action.
Using the correctly calibrated brake-pedal-tool the rears can be set to "snug", "tight", and "locked up" while on jack stands, as long as you stay away from the high spots on the hubs. But, on the road this does not manifest as good braking. The adjustment wedge has been advanced quite a lot.Per club members,m “more than should be needed”.
On the road adjusting requires so much adjusting of the wedge, the wheels will not freely turn with no pedal pressure.
Similar problem with emergency brakes.
The whole assemblies have been removed by club members, adjustment shafts measured and changed, pad thickness measured, adjustment wedges changed, etc.
Both rear assemblies have the same sticking problem for about the same ° of rotation. Axles are not bent. Bearings are new and greased. Shims not needed. Nut torqued to 125 ft-lbs. Anti Rattle springs and brake pedal return springs are new.
Please advise. Has anyone seen this with new assemblies?
Plan to call RG after I get a bivy of responses. My club and I are stumped.
Will
rotorwrench
Well-known member
Shoes really should be arced to fit the drums. Randy generally trues the drums back to standard diameter after he installs & swages the hub to drum & wheel studs. This will center the drums. Normally, the drums will fit and rotate after all this and leaving a bit of room to adjust the rotating wedge for shoe fit to give just bit of friction on the drums.
It seems to me like something isn't concentric here. I don't know what but the following would be variables:
I would check the drums for diameter in several places around the ID to make sure they are at least standard or maybe a bit oversize. A person wants all the meat they can get with new drums. I think the drums are a bit undersize when new and prior to swaging. Re-checking for concentricity after truing should be done with a problem like this. A drum lathe would be the easiest way to check that. It would take special tooling otherwise.
Check lining thickness on all the shoes. Some are too thick but they work OK on worn drums that have been turned oversize so that could be a problem here. I'm also curious about what type of linings are being utilized in this case. Some are woven and some are solid material.
If the backing plates were rebuilt then I would be more confident that they are true. On Reproduction parts, I think I would try to find some way of checking them for concentricity. I haven't heard of any problems with them but I've not used any yet either. If the center hole isn't concentric with the outer ID then I'd question if they were made correctly.
The hub & drum have to be installed on the axle & torqued up to see if the hub/drum run concentric on the rear axle
Maybe others will have more ideas to check. I'm old enough to know that I can make mistakes on stuff. I don't know if this is the case but no stones should be unturned to get to the bottom of this problem.
It seems to me like something isn't concentric here. I don't know what but the following would be variables:
I would check the drums for diameter in several places around the ID to make sure they are at least standard or maybe a bit oversize. A person wants all the meat they can get with new drums. I think the drums are a bit undersize when new and prior to swaging. Re-checking for concentricity after truing should be done with a problem like this. A drum lathe would be the easiest way to check that. It would take special tooling otherwise.
Check lining thickness on all the shoes. Some are too thick but they work OK on worn drums that have been turned oversize so that could be a problem here. I'm also curious about what type of linings are being utilized in this case. Some are woven and some are solid material.
If the backing plates were rebuilt then I would be more confident that they are true. On Reproduction parts, I think I would try to find some way of checking them for concentricity. I haven't heard of any problems with them but I've not used any yet either. If the center hole isn't concentric with the outer ID then I'd question if they were made correctly.
The hub & drum have to be installed on the axle & torqued up to see if the hub/drum run concentric on the rear axle
Maybe others will have more ideas to check. I'm old enough to know that I can make mistakes on stuff. I don't know if this is the case but no stones should be unturned to get to the bottom of this problem.
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Y-Blockhead
Well-known member
I always like to start at the beginning. You state "Brake pedal has no play". Does that mean you have no free play? Ensure the levers on the cross shaft are adjust to straight up and down. A lot of people knock themselves out and the problem is a simple adjustment between the brake pedal and cross shaft. Continue following the system out till you reach the brakes or find the issue along the way.
Ain't old cars fun?
nkaminar
Well-known member
Take the backing plates off. Mount a dial indicator to measure runout of the inside diameter of the drums. Measure near the lip and near the base.
Check the OD of the axle housing where the bearings sit. Make sure it is not worn at the bottom. If the bearing surface is worn then the axle itself can cause the drum to not run concentric. The roller bearing is what should determine the rotation of the hub and drum, not the axle.
Check the OD of the axle housing where the bearings sit. Make sure it is not worn at the bottom. If the bearing surface is worn then the axle itself can cause the drum to not run concentric. The roller bearing is what should determine the rotation of the hub and drum, not the axle.
A few things I can think of:
Make certain the adjusting shafts are not installed incorrectly against the adjusting wedge. Things will get very tight. This matches your description.
As Neal states, the race on the rear axle housing wears on the bottom??? As I recall, 2.061 - 2.063 are the specs.
Is the rear axle on jack stands or is the back end supported under the frame? Should be rear axle housings on jack stands.
If one brake rod hits a limit and stops moving, little or no movement is allowed in the other 3 rods???
With the brake rods removed at the rear wheels, what happens when you operate them with your hand moving the lever at the backing plate?
Is the transmission stock Model A?, some T5 conversions move the x shaft back 5"?? and all rods are modified lengths. Lever clevis forks do not align accurately to the x shaft.
Are the levers on the left and right rears positioned correctly? Fore and aft? Rear levers should lean toward the rear of the car ~ 5 degrees???
The clevis forks on the rear levers must aim toward the frame rails a few degrees. As I recall, there is only one rear backing plate. It is symmetrical horizontally. With the shoes off, the cam can be rotated 180 degrees and installed on the opposite rear incorrectly????
Are the clevis forks on the rear brakes side of the dual lever aimed correctly? If the x shaft was rebuilt they have been removed and reinstalled???
Remove the emergency brake band from the carrier. What happens then?
Are the toggle links installed as shown in the Les Andrews red book? There is a slight twist in the ebrake band if the toggles are not correctly installed.
Make certain the adjusting shafts are not installed incorrectly against the adjusting wedge. Things will get very tight. This matches your description.
As Neal states, the race on the rear axle housing wears on the bottom??? As I recall, 2.061 - 2.063 are the specs.
Is the rear axle on jack stands or is the back end supported under the frame? Should be rear axle housings on jack stands.
If one brake rod hits a limit and stops moving, little or no movement is allowed in the other 3 rods???
With the brake rods removed at the rear wheels, what happens when you operate them with your hand moving the lever at the backing plate?
Is the transmission stock Model A?, some T5 conversions move the x shaft back 5"?? and all rods are modified lengths. Lever clevis forks do not align accurately to the x shaft.
Are the levers on the left and right rears positioned correctly? Fore and aft? Rear levers should lean toward the rear of the car ~ 5 degrees???
The clevis forks on the rear levers must aim toward the frame rails a few degrees. As I recall, there is only one rear backing plate. It is symmetrical horizontally. With the shoes off, the cam can be rotated 180 degrees and installed on the opposite rear incorrectly????
Are the clevis forks on the rear brakes side of the dual lever aimed correctly? If the x shaft was rebuilt they have been removed and reinstalled???
Remove the emergency brake band from the carrier. What happens then?
Are the toggle links installed as shown in the Les Andrews red book? There is a slight twist in the ebrake band if the toggles are not correctly installed.
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Gold Digger
Well-known member
I remember back years ago on an old bandjo type rear end car that the axel taper was kind of haggled up along where the key fit in it. Someone had took a punch or chisel and tried to reform the axel along the key. This in turn made the hub turn ungeometrical from what it was suppose to. The brakes done what exactly as described. There could be any little piece of something either on the axel or inside the taper of the hub. Just something to check.
Keith True
Well-known member
Try removing the hubs,and the key.Make sure the edges of the keyway are perfectly even with the axle,with no burrs or edges sticking up.Install the hub again without the key,tighten it up,,and spin it around.See if it does the same thing.