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View Full Version : Brakes: Looking for Ideas, adjusters out of range?



karterfred88
07-09-2015, 09:38 AM
On my 63 Avanti, I've been trying to adjust the rear brakes with the eccentrics but can't seem to get them tight enough to get the right rear drum adjustment. The eccentric bolts are brand new from SI, linings brand new from another vendor, drums measure okay, new 3/4" correct wheel cylinders, nothing looks worn at the pivots. I can completely turn them without ever tightening them up enough in any position to get the rears to work right. Any tricks I could try? Most likely it's a combination of too thin new lining material and maxed out drum diameter, or is it possible the eccentrics don't have enough offset? I have to pass a braking test here in Delaware to get plates and right now it won't lock up the rears enough to show maximum braking effort on their test bench. the front disks are fine at 100% but the rears are at 50% and 70% meaning they aren't getting enough contact or pressure. The system is split with a 1 1/8" master matching the original design specs from Bendix. Never having been able to drive it till now, due to assorted mechanical issues, I don't have a reference as to how well it should stop. Although I had a 63 GT with disks in 1966 and drove my dad's Avanti back then, that was a long time ago, and of course I've been spoiled by todays brakes for many years. Other than adjusting the hand brake cables to take up some of the room--any ideas. I don't want to buy new drums and another set of linings as I eventually want to convert to rear disks, and I would be wasting $500.00 for a temp fix. Putting on the Turner kit on the rear only and leaving the fronts doesn't seem like a good idea either.

64V-K7
07-09-2015, 10:26 AM
You WILL have to remove the drums to figure this one out, so take some pics... I just had a scenario exactly the opposite... too much lining and the wrong shoe core and I couldn't get the drums on at all.. Until...

I figured out the brakes (box) were labeled PAB53, but the steel shoe cores were stamped B173. This made the slot where the E-brake lever fits, too shallow and the shoe assembly couldn't collapse enough to get inside the drums .. but a little voodoo with a grinder and a file was invoked and all is well.The B53 and B173 shoes both fit the rear Disk brake cars, but this subtle difference drove me up a wall.

Can you effectively apply the handbrake on your car?

karterfred88
07-09-2015, 10:40 AM
Can you effectively apply the handbrake on your car?
Yes, I can get the parking brake to engage well, that's why I'm thinking the linings or drums. The parking brake has a lot more travel than the wheel cylinders. I didn't check the stamping numbers on the linings, maybe the "ears" that enter the wheel cylinders are too short? Or maybe the slot for the upper link is too deep or the link itself is worn at the base of the slot? Still that wouldn't explain why the eccentric wouldn't push the shoes out far enough to eventually lock up the drum-or at least make it very hard to rotate the drum, only enough now to get a little bit of drag. on one shoe, but not on the other. The backing plate holes seem okay and not overly large, the eccentric fits decently-not too tight or too loose--so it does spin and moves the shoe outward at both--just not far enough to get the needed contact. Do you know what the proper thickness of the lining should be? I don't have a drum micrometer/gage to check actual inside diameter against the max specs. But even if they were .080 over there still should be enough adjustment, looking at the eccentric offset to get decent lining contact. Will pull the drum and check shoe stampings to start.

gordr
07-09-2015, 11:56 AM
What about the fixed anchor at the bottom of the backing plate? Is it OK, and are the heels of the shoes that ride there OK? Will the rear brakes grab if you pump the pedal? If it was just a case of undersized shoes, pumping the brakes should make them apply, or, worst-case, pop the pistons out of the rear wheel cylinders, since there are no stops. I wonder if your rear brake lines need bleeding, still. Other than that, it sure sounds like your shoes are assembled on the wrong cores.

karterfred88
07-12-2015, 12:06 PM
:eek:Well getting ready to "pop" the drums to see what it is I installed. Here's images of what came out 2 years ago. Note-one side was riveted linings one shoe less lining than the other, one side bonded, same length each shoe, both had 2 different shoes- looking at the area going into the wheel cylinder. One side a thin long nose, one a thick nose. The bonded set, on one shoe was the number 48154 on the riveted set one shoe labeled 313548. The bonded linings were much thicker on one shoe than the other and the thickness of both greater than the riveted ones. Any ideas which, if any was the correct shoe-shoes for my Avanti? A picture of a correct pair would help to compare to my installed ones to see what I need to do to fix it right. None of the areas marked in red are the same between the two and not even consistent on each set. The parts book shows different shoes for trailing and leading but no details showing what actual differences were. I suspect the lining coverage on the trailing and leading shoes were different coverage of the steel shoe, but were there other differences in the steel shoes themselves front and rear placement?
Footnote: They were all soaked in brake fluid from blown wheel cylinder, a lot cleaner looking now.

57pack
07-12-2015, 04:52 PM
Don't know if this is your issue but, back in the day working on a brand x I found a very worn brake drum on one side with oversized brake shoes on that side.
No adjustment there either untill brake drum was replaced.

karterfred88
07-13-2015, 02:03 PM
Don't know if this is your issue but, back in the day working on a brand x I found a very worn brake drum on one side with oversized brake shoes on that side.
No adjustment there either untill brake drum was replaced.
I suspect you may be right. Studying the old brake linings, it looks like there was a concerted effort to get the thickest possible linings (and possibly modifying similar shoes), then hand ground those with course sandpaper in the high spots. I was so concerned with the leaking cylinders and the rusty goo filling the gap between the shoes and the drums, that I cleaned up the drums with brake cleaner, looked good, put everything else in new from Stude vendors and bolted it back together, to attend to the next problem, and on and on. Now that I have come full circle, back to the first problem that kept me from trying to get the car registered, in Delaware, where brake performance is tested, not a visual inspection. I'm guessing the last state inspection from PA. was a visual one and they were fixed just enough to pass and could be driven sparingly that way. It appears that didn't work out so well, by the bent front bumper, bent brake pedal, bent and seized pivot pin in the booster bracket (that kept the master cylinder travel limited). I'm trying to avoid the inevitable purchase of $400.00 worth of drums, which will summarily be discarded with a rear axle swap soon after. Although I once read an older forum post that "there was nothing as expensive to repair than a cheap Avanti", this one was not that cheap, just filled with hidden problems from 50 years of butchery.

StudeRich
07-14-2015, 12:40 AM
It IS your Car I understand, but here is a better option for you.
Do not get all wrapped up in the idea that all Cars NEED Rear Disc Brakes!

Absolutely NOT NECESSARY, what I would do is, rebuild the Rear Brakes with New 11 Inch Finned Drums NOW, and install the Turner Front Discs. when you can afford it, your Avanti will stop as fast as you will ever need. Using the stock rear setup does not require an equalizer valve, residual valves or anything to run the Turner Front Discs.

Once the brakes are locked, you are at the mercy of the Tires to stop you, and you can't stop any faster than they allow.

karterfred88
07-14-2015, 07:22 AM
It IS your Car I understand, but here is a better option for you.
Do not get all wrapped up in the idea that all Cars NEED Rear Disc Brakes!

Absolutely NOT NECESSARY, what I would do is, rebuild the Rear Brakes with New 11 Inch Finned Drums NOW, and install the Turner Front Discs. when you can afford it, your Avanti will stop as fast as you will ever need. Using the stock rear setup does not require an equalizer valve, residual valves or anything to run the Turner Front Discs.

Once the brakes are locked, you are at the mercy of the Tires to stop you, and you can't stop any faster than they allow.

I know. But, driving this car with a 4.09 rear makes it worthless over 45 MPH. If I add the cost of brake drums, new differential carrier for
3.73 and down, new ring and pinion, bearings seals and substituting flanged for tapered axles, together I'm up over $1800.00 with labor (I'm not up to heavy duty rear end work and the tools needed) , then the prospect of paying another $400.00+ down the road if I need new drums again, it becomes a "no-brainer" to swap the rear end assembly, put in disks at the same time, and get replacement parts--like new rotors for under $50.00 each! I have no need for disk brakes on the rear really, but since I'm stuck right now at $400.00 plus shipping for something that only partially fixes my problem. Verses a used Ford 8.8 with disk brakes and internal drum style parking brakes, a usable rear ratio, with all new brake parts, cost of welding new spring perches and traction bar mounts for around $600.00 total it makes it hard to spend $400.00 now--. I'd be happy with putting on some slightly used drums if anyone near Delaware had some for sale--inexpensively--as a stop gap measure.

sweetolbob
07-14-2015, 07:55 AM
I know. But, driving this car with a 4.09 rear makes it worthless over 45 MPH. If I add the cost of brake drums, new differential carrier for
3.73 and down, new ring and pinion, bearings seals and substituting flanged for tapered axles, together I'm up over $1800.00 with labor (I'm not up to heavy duty rear end work and the tools needed) , then the prospect of paying another $400.00+ down the road if I need new drums again, it becomes a "no-brainer" to swap the rear end assembly, put in disks at the same time, and get replacement parts--like new rotors for under $50.00 each! I have no need for disk brakes on the rear really, but since I'm stuck right now at $400.00 plus shipping for something that only partially fixes my problem. Verses a used Ford 8.8 with disk brakes and internal drum style parking brakes, a usable rear ratio, with all new brake parts, cost of welding new spring perches and traction bar mounts for around $600.00 total it makes it hard to spend $400.00 now--. I'd be happy with putting on some slightly used drums if anyone near Delaware had some for sale--inexpensively--as a stop gap measure.

Well said, couple that with a dual M/C and proportioning valve and you have a winner on your hands. Bob

karterfred88
07-14-2015, 08:51 AM
Well said, couple that with a dual M/C and proportioning valve and you have a winner on your hands. Bob
Already did the dual master, and a new booster, just need the proportioning valve. Now if sbca96 can get his Mustang front brake adapters redone, I'll have the equivalent of new Mustang GT brakes, that I can afford to actually use up as needed.

karterfred88
07-24-2015, 10:30 AM
Rather than start a new thread, first thanks to those that offered to help but weren't able to. I'm going a different direction by trying some non-Stude drums and adapting as necessary as I don't plan on keeping them on there anyway. As an aside, before putting things together, I noticed the linings, sold to me from a reputable vendor, were incorrectly relined (lining bonded to bottom 2/3 of shoe rather than top 2/3). Before shoving this thing out of the garage again, does anyone have a lead on a vendor selling them done correctly?

StudeRich
07-24-2015, 12:24 PM
Some Shoes come with the short Shoe fully Lined, some short in the center, some at the bottom, some at the Top, no one has noticed any difference in braking. The Reliners of today do not know or care which is Engineering "Correct". :(

karterfred88
07-24-2015, 12:39 PM
Some Shoes come with the short Shoe fully Lined, some short in the center, some at the bottom, some at the Top, no one has noticed any difference in braking. The Reliners of today do not know or care which is Engineering "Correct". :(
I know! But this way the first thing to touch your drum is the metal shoe, since it pivots on the bottom and outward at the top from the wheel cylinder, part of my minimal braking force problem. That spot just under the arrow actually touches as the lining begins to engage the drum.

StudeRich
07-24-2015, 12:50 PM
Here is a Set you can buy if you think this is better, the Upper Shoe in the Picture is the Shorter Shoe that goes to the Rear, it's only a 7/8 Inch Shorter.

45900

karterfred88
07-24-2015, 01:11 PM
It's the blank area at the wheel cylinder end that concerns me, on mine the "full shoe" has 1" blank to the lining on the wheel cylinder end, and the "primary" short one has 21/2" blank to the lining. I'm not sure exactly what the maximum blank can be before it becomes a problem. Since they swing out around the bottom pivot, I bet there is a critical point. Have you actually used those in the Avanti without problems?

StudeRich
07-24-2015, 01:19 PM
Yes I have sold those before, I did not install them. I don't believe you ever did say exactly HOW big your Drums really are, are they about .070-.090 over 11 Inches maybe?

karterfred88
07-24-2015, 02:23 PM
Yes I have sold those before, I did not install them. I don't believe you ever did say exactly HOW big your Drums really are, are they about .070-.090 over 11 Inches maybe?
I'm guessing but, I'd say at least 070 although they had been turned that way, so the PO knew it, as the linings I took out were assorted riveted and bonded, some on 176 shoes, some on I think 53A and chosen for thickness of lining. I don't have a drum micrometer, but since I never could get one side to really drag and was able to "spin" the eccentrics 360, with the "new" linings on one side and get just barely enough drag on the other to say it was "okay". I sure don't want to stick a new drum on the "new" linings as they are really wrong, and the ones I took off were badly contaminated by leaking wheel cylinders. Although I don't plan to drive it a lot once it passes DMV inspection, I didn't "plan" on it being almost four years getting to this point either.

Alan
07-24-2015, 02:29 PM
Fred; You could always send the brake shoes to me and I could fix them for you.

karterfred88
07-26-2015, 12:36 PM
Thanks Alan. but before doing that I have to figure out which of the shoes I have are actually the correct ones, if any! I have laid them side by side, over each other and, quite frankly, only 2 appear to be identical, and they are one from the old set and one from the new ones I installed! Every one seems different, either in the width of the wheel cylinder end, length of the shoe going into the cylinder, distance from the lower spring hole to the "heel" of the shoe contacting the pivot. Shape of the "heel", amount the heel offsets the shoe from the pivot, depth of the parking brake "slot", shape of the parking brake slot and on and on. I'll either need to have a real set of the right linings, or a template of the correct ones, so I can mix, match, and modify as needed to get four correct shoes. What a mess.

bezhawk
07-26-2015, 12:46 PM
If your drums are .070 oversize, throw them away. It's illegal for any state inspector to pass them . .060 is the federal limit. (for a reason)

karterfred88
07-26-2015, 01:30 PM
If your drums are .070 oversize, throw them away. It's illegal for any state inspector to pass them . .060 is the federal limit. (for a reason)
That was already a forgone conclusion (#18), the problem is which of the eight shoes should go back in with the new drums! That aside, no one inspects them here in Delaware, The brakes are "tested" on a drive on test bed, reading percentage of braking power at each wheel. Could be leaking like a pig, as long as it properly decelerates each wheel. "Foot Brake - Must stop vehicle within distance of 20 feet from a speed of 20 miles per hour on dry pavement. Brakes must be adjusted to work evenly on opposite sides of vehicle."

StudeRich
07-26-2015, 06:56 PM
Did you try comparing your 8 Shoes to the Webs of the New Set I photo'd and Posted for you?
The Lining placement may not be the best, but the Actual Shoes should give you some idea.

karterfred88
07-26-2015, 11:09 PM
Did you try comparing your 8 Shoes to the Webs of the New Set I photo'd and Posted for you?
The Lining placement may not be the best, but the Actual Shoes should give you some idea.
Yes, but I have four that appear "nearly" the same as yours, if I use shoes from the old and new, but on two of them, the slot where the e-brake bar enters the shoe, the slot is 1/2+/- the "width" (height) of the bar and would have to be filed to allow it to seat completely. However the lower round "spring hole"(not used to install) is a different distance from the center of the lower pivot, thus putting one shoe further away than the other on one pair (the ones with the smaller "slot". The other 4 all have, fat noses that barely enter the wheel cylinder. I realize over the years, that with the original linings having become rare, that all kinds of substitutions, closely fitting shoes have been modified to work. Unfortunately from what I have, it would take an expert to figure which to reuse and reline correctly. As every "vendor" wants cores as an exchange, I would never know which to send. Tomorrow I will pull all the shoes, line them up and photo them, then maybe we can decide which four would be useable as cores.

hobiejack11
07-27-2015, 06:54 PM
Back in the day Chrysler products had very similar brakes and I repaired hundreds if not thousands of them. The first thing I can say emphatically is that if your drums are more than .060" oversize then you will never get satisfactory rear brakes using them. This type of brakes rest on a fixed anchor at the bottom and are moved out to contact the drum by the wheel cylinder at the top. In order to get a good pedal we always used a device known as a brake doctor in conjunction with a caliper that measured both the drum and the shoes. If you will notice the bottom anchor as well as the bottom of the shoes is angled so as to automatically move the bottom of the shoe out as it wears. The eccentric moves the top of the shoe out to bring it as close to the drum as possible without dragging. The wheel cylinder them simply moves out to the top of the shoe and stays there as there is nothing to return it. With all new parts and proper adjustment this is not a very good braking system. It is not self energizing and is very sensitive to proper adjustment. That is the reason that Chrysler abandoned it in 1949. My advice is to find a good 8" Ford with a suitable ratio and pitch the whole rear end . You may even be able to sell it to some purist who wants to keep his car all Studebaker.

hobiejack11
07-27-2015, 11:10 PM
I got to thinking about my earlier post and I realized that I was mistaken about part of what I said. It was Ford that ditched their fixed anchor system in 1949 in favor of the Bendix self energizing type. Chrysler kept their system for some time longer, sometime in the late 50's or maybe even the early 60's. I know that this is not really important to your issue but I am sure some other old timer would call me on it. The really important thing is that you will never be able to get effective rear brakes with badly oversize drums and mismatched shoes. If you want to keep the axle you have now you will have to get new or good used drums and the correct shoes to have a chance.

karterfred88
07-27-2015, 11:24 PM
Well been there done that, and as I disassembled the rest today, I was able to find 3 shoes which are definitely "right" stamped FMS173 and Bendix with a web stamping of 313548. Three others are stamped with that same web stamping but missing the FMS173 on the lining backing plate. All of them have seen a grinder or been massaged at the wheel cylinder end, not enough to ruin them. Two are definitely wrong as the wheel cylinder entry end is shorter and wider by a lot. One of the "correct" shoes was so heavily rusted before being relined that I could chip out pieces of the backing and see the lining material. On a lighter side, one of the retaining clips I was cleaning, looked a little bent. Placed it on edge to straighten it and, looking carefully, saw the backing plate part was original, but the hold down portion was a welded on piece of steel from some "Olympia Beer" container of some sort, at least that wasn't rusted through. I think they had one too many of those while putting on the one side of the rear brakes!!
Waiting on new drums tomorrow, per FedEx, then see if I can mix and match enough to get by for now.

hobiejack11
07-28-2015, 11:28 AM
Make sure you have the correct shoes. If i were doing it I would talk to as many vendors as I could find until I found one who could speak to your problem with authority. Then I would exchange your mismash of shoes for a set that he will guarantee to be correct for your car. I have a caliper that is made to compare the drum inner diameter to the shoe outer diameter. If you can't find one in your area I could send it to you by USPS flat rate. You have to promise to return it ,of course. You can probably find one in your area by sweet talking someone in a brake shop that has been in business for a long time. I will post a pic if you are interested.
Hobie

karterfred88
07-28-2015, 02:07 PM
Make sure you have the correct shoes. If i were doing it I would talk to as many vendors as I could find until I found one who could speak to your problem with authority. Then I would exchange your mismash of shoes for a set that he will guarantee to be correct for your car. I have a caliper that is made to compare the drum inner diameter to the shoe outer diameter. If you can't find one in your area I could send it to you by USPS flat rate. You have to promise to return it ,of course. You can probably find one in your area by sweet talking someone in a brake shop that has been in business for a long time. I will post a pic if you are interested.
Hobie
Thanks for the offer! All the relined "primary shoes" are incorrect, even some new ones offered on E-Bay, the linings need to start near the cylinder ears and end short on the shoe bottom, all mine were done the opposite way, leading to a VERY SHORT life span and early contact with the drum by bare steel. Frankly even a fully lined shoe would be better, as the short lining "theory" really doesn't matter, but placement of the material on the shoe does, to protect the drum, as the upper part of the lining wears faster than the rest due to the fixed lower pivot. I wish I had a shop nearby that actually does the relining, but this is a temp fix only, so I'll find a solution that doesn't destroy the new drums and get on with it..Then I can sell them as good used drums and get back 1/2 of my investment.

karterfred88
07-28-2015, 02:11 PM
Fred; You could always send the brake shoes to me and I could fix them for you.
PM sent thanks for the offer

63t-cab
07-28-2015, 03:14 PM
Frederik, You mention some on "176" shoes, I believe 177 is on target.

I'm guessing but, I'd say at least 070 although they had been turned that way, so the PO knew it, as the linings I took out were assorted riveted and bonded, some on 176 shoes, some on I think 53A and chosen for thickness of lining. I don't have a drum micrometer, but since I never could get one side to really drag and was able to "spin" the eccentrics 360, with the "new" linings on one side and get just barely enough drag on the other to say it was "okay". I sure don't want to stick a new drum on the "new" linings as they are really wrong, and the ones I took off were badly contaminated by leaking wheel cylinders. Although I don't plan to drive it a lot once it passes DMV inspection, I didn't "plan" on it being almost four years getting to this point either.

karterfred88
07-28-2015, 04:04 PM
Frederik, You mention some on "176" shoes, I believe 177 is on target.
Well, days of searching found that 173 shoes are actually the "correct" ones. From the archives of Bob Johnstone's site:

"I made an error in discussing the rear brake shoes. The #176 shoes shown on the Autozone site is completely wrong for the Avanti. That shoe is for cars with the standard drum brake. The 7/8" wheel cylinders are wrong also. The Avanti uses 3/4" wheel cylinders and #173 shoes. Now the #53 shoes for Stude trucks are very close, the only difference is in the linings and the tab that fits into the wheel cylinder is slightly wider. Again, a mill file can be used to take a bit of metal from the tab to make it fit. The tab dimension on the #53 shoe is 27/64" "

Like the argument over master cylinder bore, rear wheel cylinder bores and right shoes there is disagreement. I found the original specifications from Bendix for the system, so I know M/C 1 1/8", Rear wheel cylinders 3/4", front pistons 2 1/8". But never could find anything except Studebaker part numbers verses several different "opinions" about the correct cross reference. The 173 shoes I have seem to be the best fit on the backing plates and fit the wheel cylinder pistons best, but the rear shoes are all lined improperly per various Avanti manual photos.

hobiejack11
07-28-2015, 10:39 PM
As I mentioned before, the shoes ride in the anchor on an angle that is supposed to bring the bottom of the shoe closer to the drum as the lining wears and the brakes are applied. On this type of brakes I always put a "very" small dab of lubriplate on the bottom of the shoe so that it could ride along the angle and in effect adjust the bottom of the shoe in. Actually the rear shoe is not that much shorter than the front. Make sure that you don't put too much lubriplate on the anchor and the contact point as even though lubriplate will cling to where ever you put it too much could drop down on your drum and contaminate your shoes and that is not good. The bottom of the shoe needs to slide in the anchor in order to maintain a good pedal for any length of time.

karterfred88
07-30-2015, 11:34 AM
:mad:
Help!
Since so many things have gone wrong in this "brake" repair, I have become paranoid and started really looking at my parts especially since the "beer container" hold down clip. The left side brakes were the "home" of this item. Now looking closely, the bar for the e-brake is worn in a curve on one side on the edge, like it was rubbing something round, at some point in history. Looks useable. Pulling the drum off the hub, I'm using a "replacement" style drum that I can easily remove, pulled the lug bolts and was on my way to the machine shop to press in new studs. Inspecting the hub carefully it looked funny. The seal surface, rough and "burned" looking. comparing the keyway slot on the two hubs, it looked like the keyway had been machined much deeper on the inside on that hub. Really close examination revealed a small welded area right over the keyway on the seal surface that had been ground, but some very small weld spatter spots still visible. There is also a gouge mark inside the taper about 1 inch in, going 1/2 to 2/3 around the inside. Theory- nut tightened with key upside down, nut left loose, wheel and hub backed off taper and either almost fell off axle end or did. Patched up any old way and sold to the next customer. The axle end appears ok and doesn't show any obvious run out at the end. Much more corrosion than the other side but wipes off with some soft steel wool. Even though my plan is to get rid of the rear assembly, now is not that time. I need a good tapered axle hub only for now, this one is not going back on. Anyone have a spare, with no drum, lugs or no lugs fine with me. Or any idea where to get just a hub part number 533901?