1939 Rear Brakes - I'm Going Nutz-O

[Rebel Sympathy]

Howdy Boys:

I've got a problem with my rear brakes. This car has 33,000 original miles and has sat up long enough that the rear brakes needed the wheel cylinders rebuilt and new lining. (So did the fronts, but I don't have a problem there.)

With the cams turned all the way in and the eccentics turned where the two dots are facing each other, I can barely get the drums to go on. When I do get them on, the rear brakes drag so badly that it feels like the parking brake is on. I'm using the original Ford shoes and I had them relined at Automotive Friction in Birmingham. They strongly suggested woven lining and I honored their request.

The lining appears to be about .200" thick, or just over 3/16". Using digital calipers the shoe and lining measure about .328". The shoe measures about .120" for a net lining thickness of about .200". I believe I have the shoes in the correct position with regard to the anti-rattle brackets. It is almost as though the parking brake link between the two shoes is too long. But, of course, it cannot be that.

Is the lining too thick? Any other suggestions? Thank you for any suggestions.

Mike

[Charlie Stephens]

Did they arc the shoes to the correct drum diameter? That is probably the problem. With so few miles the drums are probably not more than .010 over. When I bought relined shoes a few years ago I was told that they arced everything for .030 assuming all drums would be at least that far out.

Charlie Stephens

[Rebel Sympathy]

Charlie:

I asked these guys about bringing the drums down to them with the shoes so that they could arc the shoes. They said they did not arc shoes anymore and not to worry about it, that the lining would quickly enough wear to fit the diameter of the drums. So, I went to 2-3 other places and asked if they could arc shoes. Everybody said "No"; that they did not offer that service anymore.....!!!! Therefore, I just put them on. I doubt this car has ever had the rear drums turned. I don't know.... maybe that is the problem. Hopefully, some others with provide additional answers which will confirm the importance of arcing, or steer me to another possible solution to my problem.

Thank you for your suggestion.

Mike

[Mart]

Try turning the lower adjusters a little more, so the left one as you look at it from the dot side has the dot between the 1 and 2 o'clock position and the right one has the dot between the 10 and 11 o'clock position.

This MIGHT get the heels of the shoes clear if that is where the problem lies.

Other than that you could pull the drums, lay the shoes in and see how well they fit inside the drum.

[Charlie Stephens]

Originally Posted by Rebel Sympathy

Charlie:

I asked these guys about bringing the drums down to them with the shoes soa that they could arc the shoes. They said they did not arc shoes anymore and not to worry about it, that the lining would quickly enough wear to fit the diameter of the drums. So, I went to 2-3 other places and asked if they could arc shoes. Everybody said "No"; that they did not offer that service anymore.....!!!! Therefore, I just put them on. I doubt this car has ever had the rear drums turned. I don't know.... maybe that is the problem. Hopefully, some others with provide additional answers which will confirm the importance of arcing, or steer me to another possible solution to my problem.

Thank you for your suggestion.

Mike

The problem with arcing the shoes is that the dust generated when the shoes are arced needs to be filtered out before it gets into the air to meet OSHA, AQMD etc requirements. The equipment is expensive and only companies that do a lot of relining have invested in it. Hopefully someone can point you in the right direction. You might ask someone in a local old car club what they do to solve the problem. Plan on spending a lot of time on the phone. Maybe have the drums measured locally and send the shoes to someone with the equipment.

Charlie Stephens

[Kube]

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Two things: 1) Did you get the drums turned? If not, do it... most likely they are not round any longer. To do a brake job without turning the drums will only cause problems.
2) as has been suggested, the shoes really do need to be arced to the diameter of the drum. Very often (more often than not) the shoes are warped and / or the linings too thick.
The only way to be certain you have compensated for the aforementioned problems is to arc the shoes.

[Rebel Sympathy]

Originally Posted by Mart

Try turning the lower adjusters a little more, so the left one as you look at it from the dot side has the dot between the 1 and 2 o'clock position and the right one has the dot between the 10 and 11 o'clock position.

This MIGHT get the heels of the shoes clear if that is where the problem lies.

Other than that you could pull the drums, lay the shoes in and see how well they fit inside the drum.

Mart:
I have already done exactly as you have said with the lower adjusters. Did not work. I will take your advice about laying the shoes in the drums. That's a good idea....
Mike

[Rebel Sympathy]

Originally Posted by Kube

Two things: 1) Did you get the drums turned? If not, do it... most likely they are not round any longer. To do a brake job without turning the drums will only cause problems.
2) as has been suggested, the shoes really do need to be arced to the diameter of the drum. Very often (more often than not) the shoes are warped and / or the linings too thick.
The only way to be certain you have compensated for the aforementioned problems is to arc the shoes.

Thanks, Kube. It is looking more and more like I am going to have to find someone, somewhere who will arc the shoes. Or...... maybe do like Ken/Alabama did (old post), which is to arc his own shoes with adhesive backed sandpaper stuck inside his drums as a friction material.
I tell you what, if you saw how nice and smooth these 33,000 mile rear drums are (no grooves, etc.), you would cry before you had them turned. I just cannot bring my own self to do it - at least not yet.
Mike

[MuskegonFlatheadFan]

"do like Ken/Alabama did (old post), which is to arc his own shoes with adhesive backed sandpaper stuck inside his drums as a friction material."
I have done this too, and it has worked out fine.

[Rebel Sympathy]

Originally Posted by MuskegonFlatheadFan

"do like Ken/Alabama did (old post), which is to arc his own shoes with adhesive backed sandpaper stuck inside his drums as a friction material."
I have done this too, and it has worked out fine.

Thanks, Muskegon:

From the sound of things, I believe that is where I am headed.....

Mike

[Kube]

To arc your shoes as Ken suggests is okay. However, if the shoes are warped (very likely) you will leave that warpage in. Once the shoes are installed, the contact will be better than if you had not done this but less than if you had them arced with a machine.
I understand your apprehension over turning the drums.
Still, you need to eliminate any warpage and out of round conditions.
Will everything be "okay" if you stay with the drums as is and arc the shoes with paper? Sure, they'll be okay.

[richard crow]

check the hand brake cable make sure it is loose so that the levers on the shoes are all the way back touching the brake shoe make sure the cross link is seated right

[hardtimes]

Hey Mike,
Even with 'only' 33K miles of wear on them, you can be sure that there is some wear on your drums, no? Well, if there is any wear, the drums will make better stopping power with cleaned up surfaces without doubt...over outofround/glazed/hot spot original surface!
Try minimal drum cut first, then if they fit your better off. But, hand arcing with that cut would make you best brakes for the money/work you've invested, IMO.

[FlatheadTed]

I do a lot of brake work and strike this problem lots , if you feel the drums are in good condition then I would not touch them except sand them (60 grit ) .You can chalk the drum then push the shoe on and get the chalk transfered onto the lining ,sand the marked area by using a flat block of wood or even a body mans flat foam backed sir-form with 60 grit .You can glue the paper to a drum but this gives you a slightly smaller lining and the chances of you getting the drum on with paper is nil . If you work away at it with the sand paper till it goes on then the sanded drum face will hone the finial shape with use ,You may get a little heat but don't worry as they get plenty hot under normal braking ,The stock lining size is 3/16 with drums at 12"

[Straightpipes]

I would be checking the drums. Even if they are low mileage they have been pulled from the axle. If they were not pulled correctly ( not to say you didn't ) they can easily be warped.
I have also arced shoes with the "at home" method and it worked for me. But the drums have to be round. Please don't go Nuts-O there are too many Nuts-Os already......

[bgarrett]

the shoe is only touching the drum at each end of the shoe so take a power sander and grind off the end of each shoe a little at a slight angle. dont inhale

I sure wont waste any life of my drum by turning the drum to a larger diameter

[Kirby1374]

I recently have put juice brakes om my A. The rear drums would not go on. I looked at the parking brake links and someone had added (welded up the slots some) to the inside of the cross link so that even with no cable hooked up it was sort of applying the parking brake. I round filed the slot a bit deeper and got it all to fit. I would check the whole shoe assembly in the drum (Pbrake assembly and bottom adjusters attached to shoes) if it will not fit file that slot in the P brake linkage until it does. It may not take much.

[2935ford]

Just a thought.....I'm doing the same. My problem turns out to be incorrect cylinders (offshore) to long.
I think you have rebuilt your originals, though, correct?

[Rebel Sympathy]

Originally Posted by 2935ford

Just a thought.....I'm doing the same. My problem turns out to be incorrect cylinders (from China) to long.
I think you have rebuilt your originals, though, correct?

Yes, I have honed the original cylinders and put kits in them. Mike

[Rebel Sympathy]

Boys:
I thank all of you for your help. I at least now know that it is "normal" to have this problem with new lining, especially without arcing the shoes. Now that I know what the problem is, I will carefully and properly address it. What a helpful group this is.
Much obliged to all who contributed.
Mike

[jrhaelig]

Reb -

I found that mine had a rust lip built up on the outer edge of the shoe contact area. I Dremeled that down and the drums went on fine.

[wspiker]

Hi, I went through the EXACT same thing you are going through ten months ago. I even did as you have and asked for help on the Ford Barn. It turns out it was the cam adjustment on the rear. A friend of mine came over and did what needed to be done and it worked? I just couldn't do it? Also, heads up, the brakes were tightening up after driving a short distance? That turns out to be the master cylinder needed to be adjusted for the 'free play' on the brake pedal. It wasn't allowing the expanded (heated fluid) to return to the master cyclinder. As a result, the brakes were engaging.........

Thanks again to the good folks at the Ford Barn who let me know what was happening and offered their advise................. You'll get it............ :-)

[wspiker]

Hi, I went through the EXACT same thing you are going through ten months ago. I even did as you have and asked for help on the Ford Barn. It turns out it was the cam adjustment on the rear. A friend of mine came over and did what needed to be done and it worked? I just couldn't do it? Also, heads up, the brakes were tightening up after driving a short distance? That turns out to be the master cylinder needed to be adjusted for the 'free play' on the brake pedal. It wasn't allowing the expanded (heated fluid) to return to the master cyclinder. As a result, the brakes were engaging.........

Thanks again to the good folks at the Ford Barn who let me know what was happening and offered their advise................. You'll get it............ :-)

[Bassman/NZ]

Considering the state of your drums, I would follow Flathead Ted's advice. As he says, he's done a LOT of brake jobs.

[47Merc]

You should also remember that it is best to use a torque wrench when you tighten up the wheel nuts on a 39 with the wide 5 wheel rims.

The reason for this is the wheel studs are on the outer edge of the drum and not like normal hubs where the studs pull on the axles.

If the tension on the wheel nuts is not uniform it can (and will) pull the drum out of round. This can be felt through the brake pedal pulsating like a warped disc does and is particularly noticable on the fronts.

[woodypecker]

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Thanks for all of the good information again I have learned a lot by lurking and listening

[FRANK PKNY]

Year's ago without much money, I would just get the shoes to fit when assembling and keep adjusting till they wore in . It takes about 1000 miles per adjustment, two adjustment most of the time works fine. Pedel may be a bit soft at first, till the lining wears in. Not rocket science the 39 adjustments are somewhat diffacult to do because the lineings do not float like the later style. I talked to a guy about two years ago that was trying to develop a conversion to get the shoes to float, but have not heard if he was successful. I put a float kit in my 35 (mechanical brakes) and they work great, no need to to convert to hydraulic.

[Lowsquire]

I had the same problem. file the slot in the park brake link. it doesnt need much.
That part can actually be what is keeping the drums apart rather than the adjusters, and as long as you can adjust it back out with cable adjustment, you havent upset anything at all, I know its counter intuitive to change that clearance, but it is the answer. trust me.

[George/Maine]

This problem comes here often with new shoes.
The way it was done without a arching machine.
Cammfer the new lining back about 1/2, angle and depth 1/8 on ends.
At least near "first rivet".
If you bring the shoes out even 3-9 oclock 1/8 less then drum.
Most likly they will hit on top thats what the cammmfer is for,
do both end.
The pistons must be all the way in.
The high lining stops the piston from going back in.
The angle can be done with file or bench grinder thats what i use.

[Rebel Sympathy]

Thanks, boys. Your generous and helpful advice is appreciated.......

Mike

[barnfind08]

You could eliminate the problem by using genuine ford lining. already chamfered and the correct thickness. have sold many sets. for 4 linings(2 short and 2 long 32.00 plus postage.