PDA

View Full Version : Brakes: Disc Brake Conversion



lelshaddai
12-13-2018, 06:29 AM
Can a complete 64 Commander power disc brake setup bolt on a 53 Commander Coupe? Anything special need to be done?

swvalcon
12-13-2018, 07:32 AM
why bother there are better aftermarket systems out there. For most it is a selling point over the stock Studebaker brakes.

Gunslinger
12-13-2018, 07:36 AM
If you mean the discs, calipers, hoses, etc., then yes...I believe they all will work. If you're including the booster and master cylinder...no. You will also need disc brake wheels as well. I also agree with swvalcon...there are better aftermarket systems available.

sals54
12-13-2018, 09:35 AM
And don’t forget the spindles. The back of the spindle flange, where the 6 bolts are for the backing plate on the drum brakes, has a machined surface where the caliper bracket mounts. Essentially the same spindle, but with this area machined flat. Otherwise brackets won’t fit.
But, yes, I agree with those above. Go modern disc brakes if you can.
Then you must remember to fix the master cylinder. It has a 10# check valve in it. Remove that check valve and install a 10# check inline to the rear drums and a 2# check to the front discs.

studegary
12-13-2018, 09:54 AM
Can a complete 64 Commander power disc brake setup bolt on a 53 Commander Coupe? Anything special need to be done?

You can greatly improve the 1953 brake system by just bolting on the drum brakes from a later V8 Studebaker. If everything is up to "snuff", I find them to be more than adequate. I have made this simple and inexpensive conversion on several 1953 Commanders. If you insist on having discs, I also recommend going to an aftermarket conversion.

Dick Steinkamp
12-13-2018, 10:24 AM
If you are going to do that, make sure you move the REAR brakes over from the 64 also. They are matched to the front discs and quite different from the 53 drum brakes and the 54 and up drum brakes.

Gary's idea is a good one. Unless you do a lot of mountain driving or driving in deep puddles, there isn't an advantage of disc brakes over the 54-66 drum brakes (IMHO). They will both slide all 4 wheels evenly when applied fully and both can be modulated to provide maximum braking just prior to lock up without the car changing ends. An advantage of the drum brakes is that you don't need a booster. The Studebaker (Bendix) disc brakes were some of the first used on cars. They work well when rebuilt, installed, and adjusted correctly, but the technology is old school.

If you go with aftermarket discs, make sure you follow the provider's instructions on which rear brakes, master cylinder, booster, and front/rear proportioning valve to use. I would recommend you check with Jim Turner. (http://turnerbrake.com/)

lelshaddai
12-13-2018, 10:33 AM
I was just checking since I had a chance to pick some up. I already have the late 50's drum brakes on her.

PackardV8
12-13-2018, 11:24 AM
JMHO, but I'm one of the few here who still appreciates the OEM disc brake system. When everything is new it works better than drums and in other than road-racing, is entirely safe and effective in today's traffic. If I had the opportunity to pick up a complete front and rear DB system at a reasonable price, I'd rebuild and install it.

Bottom line, yes the original disc brakes are obsolete and there are better, newer available, but then that is true for every single mechanical part on a Studebaker. It's a slippery slope.

jack vines

thunderations
12-13-2018, 12:18 PM
I agree with Jack, the original Studebaker disc brakes are better then drum brakes. If they weren't do you think that Studebaker would have decided to use them? Do you not think that testing was done prior to making the decision to use discs on the Avanti?
I have the original Studebaker disc/drum brake system on my 66 Daytona with one modification, a dual master cylinder. The brakes are excellent and stop the car straight and true, quickly. Everything has been rebuilt with original parts including new steel and rubber flex lines.
I believe that the newer conversion disc brake systems are better then the original Studebaker/Jaguar systems, but unless you plan to race the car or power the car through mountain roads, not worth the conversion. The kicker to this is that totally rebuilding an original system is more costly then converting to a newer system, so that may make the decision easier to make.

If the original poster can get the 64 spindles or have his spindles machined for the Studebaker discs and the system is rebuilt it would make a nice braking system. I agree that the rear drums need to be updated also or there may be issues.


JMHO, but I'm one of the few here who still appreciates the OEM disc brake system. When everything is new it works better than drums and in other than road-racing, is entirely safe and effective in today's traffic. If I had the opportunity to pick up a complete front and rear DB system at a reasonable price, I'd rebuild and install it.

Bottom line, yes the original disc brakes are obsolete and there are better, newer available, but then that is true for every single mechanical part on a Studebaker. It's a slippery slope.

jack vines

lelshaddai
12-13-2018, 12:22 PM
Actually it has the complete front end. The frame was cut at the firewall and all the components are there including the steering column, booster, master.

gordr
12-13-2018, 12:47 PM
Then you don't have the special rear brakes, the eleven-inch by two-inch non-servo drums, with the small cylinders that can work with the disc brake system pressure, without the need for a proportioning valve. And, of course, your '64 Commander used a firewall-mounted booster and master cylinder, and the '53 has an under-floor master cylinder. Hawks equipped with disc brakes used a special Hydrovac mounted under the hood, that got pressure from the regular under-floor master cylinder.

If you really want to upgrade to disc brakes, the Turner brake kit is the way to go. But you will add unsprung weight to the front end.

lelshaddai
12-13-2018, 12:54 PM
I actually am happy with the upgraded drums I have. Was just seeing if these could work. Sounds like more effort than I need to do.

Dick Steinkamp
12-13-2018, 01:06 PM
...When everything is new it works better than drums...

jack vines


I agree with Jack, the original Studebaker disc brakes are better then drum brakes.



Can you guys define what you mean by "better".

On the same car (same weight, CG, wheels and tires) both systems (stock 54 and up drum brakes and 63-66 disc brakes) will lock all 4 evenly, and both can be modulated to apply maximum braking force prior to lock up (which would result in the shortest stopping distance). I believe both cars would stop in the same distance. If the brakes were wet (deep puddle) the discs would out perform the drums. Since the drums will fade before the discs, discs would be preferred in those circumstances (long down hills with heavy braking) where drums would fade. My personal experience is that the non-power assisted drum brakes are easier to modulate than the stock power assisted disc brakes.

I've had both setups on Studebakers (not aftermarket discs, however). Both stopped straight and true. I've always wanted to have a "stop-a-thon" at an IM to see if there is a difference. I couldn't figure out how to insure the test cars would be going the same speed and apply the brakes at the same time without some sophisticated test equipment, however.

PackardV8
12-13-2018, 02:16 PM
Interestingly, the generally most conservative US independent was the first to offer disc brakes as standard on a production car. (Crosley? fuggidaboutit; a toy car.) As previously mentioned, the Big Three OEMs had to be dragged kicking and screaming and late in the game to switch to front disc brakes. That larger tires and wheels, heavier cars, higher speeds and yes, customer demand, forced them to spend money they didn't want to spend is all we really need to know about front disc brakes being "better".

jack vines

thunderations
12-13-2018, 05:00 PM
You can "Google" (Automotive disc brakes vs drum brakes) and get the engineers reasoning for discs being better overall. Has to do with the direction energy is used to stop a rotating object. I don't understand everything I know about the subject, but have used both and prefer the discs on all 4 corners if possible.

Jessie J.
12-13-2018, 05:23 PM
One thing that isn't often mentioned about Studebaker's old original equipment Dunlop Disc Brakes, is that unlike most latter disc systems it is absolutely critical that the brake pads are regularly inspected and replaced.
The Dunlop calipers have cast in stops that prevent the metal backing on the pads from ever coming into contact with the rotor. If the disc pads are allowed to wear too thin they will come up against these stops. The Brake pedal will remain high and hard but there will be reduced or no front braking with no warning noises. I learned this the hard way at the cost of replacing the entire front clip on my ''65 Cruiser. The price of new set of rotors would have been much cheaper.
As a practical matter, unless your Studebaker is a full on restoration, that will be competing for points, there are much better, larger, (extended service life) and easier to service conversions available. The original disc system would be my last choice for anything I intended to drive regularly in modern traffic.

Dick Steinkamp
12-13-2018, 05:53 PM
You can "Google" (Automotive disc brakes vs drum brakes) and get the engineers reasoning for discs being better overall. Has to do with the direction energy is used to stop a rotating object. I don't understand everything I know about the subject, but have used both and prefer the discs on all 4 corners if possible.

I googled those words. I get several "hits". I'm not sure which one you are referring to. The top one only talks about one difference...

"This basic design proved capable under most circumstances, but it had one major flaw. Under high braking conditions, like descending a steep hill with a heavy load or repeated high-speed slow downs, drum brakes would often fade and lose effectiveness."

https://www.edmunds.com/car-technology/brakes-drum-vs-disc.html

Do you have a link that would hopefully better define the term "better"?

What I don't get, is that if both systems on the same car/wheel/tire combo will generate enough braking force to slide the tires, what good is additional braking force?

Alchemist
12-13-2018, 07:22 PM
If one were to install the whole disc brake system on a car which was not originally equipped, what proportional valve, (pressure modulating value), would be necessary to make the rear brakes operate in concert with the front discs?
Francis Prefontaine
Rolly View, Alberta

thunderations
12-13-2018, 07:32 PM
This site probably goes into the most detail and compares drums to discs. (www.tribology.fink.rs/journals/2016/2016-1/2.pdf) I will say that it looses me at times as I'm not an engineer and I really don't care about formulas and equations. Happy reading.

I googled those words. I get several "hits". I'm not sure which one you are referring to. The top one only talks about one difference...

"This basic design proved capable under most circumstances, but it had one major flaw. Under high braking conditions, like descending a steep hill with a heavy load or repeated high-speed slow downs, drum brakes would often fade and lose effectiveness."

https://www.edmunds.com/car-technology/brakes-drum-vs-disc.html

Do you have a link that would hopefully better define the term "better"?

What I don't get, is that if both systems on the same car/wheel/tire combo will generate enough braking force to slide the tires, what good is additional braking force?

sals54
12-13-2018, 08:29 PM
If one were to install the whole disc brake system on a car which was not originally equipped, what proportional valve, (pressure modulating value), would be necessary to make the rear brakes operate in concert with the front discs?
Francis Prefontaine
Rolly View, Alberta
I did my disc brake conversion many decades ago. I did not use a proportioning valve on my sytem. I did, however experiment with different diameter wheel cylinders. I can't remember which one I ended up with, but it was fun going out, and at 50-60 mph, locking up the brakes to see when they would all skid together. Shade tree methodology, but it worked.
That was when I had more time than money to spend on my car.

bensherb
12-13-2018, 10:39 PM
If one were to install the whole disc brake system on a car which was not originally equipped, what proportional valve, (pressure modulating value), would be necessary to make the rear brakes operate in concert with the front discs?
Francis Prefontaine
Rolly View, Alberta


An adjustable one. https://www.summitracing.com/parts/rsd-pv01 There are many available, this is just one of them.

I'm using the entire four wheel disk brake system from an '04 Mustang. It weighs the same as the C/K and has the same front to rear weight bias so even the proportioning is correct.

chet445
12-14-2018, 06:44 AM
I had that valve on my '62 hawk using front disc and drums rear, did not notice any difference so just removed it. I must assume the rear rear drums are working as the car stops nicely. chet445

Xcalibur
12-14-2018, 08:57 PM
Are there better brakes than the ancient Bendix/Dunlaps? Sure... but, that being said, there is nothing wrong with them, especially if on a reasonable weight vehicle.

For many years Jim Lange ran them on his Record Holding Bonneville Avanti and abused the poor things far worse than anyone ever would on the street. EVen so, they never did anything other than always bring the heavily ballasted car to a halt, including once when I was driving and the parachute failed. Man, did they stink, though, at the time... but, after allowed to cool worked fine the next day (as did the chute). :lol:

Jessie J.
12-14-2018, 11:43 PM
As long as the pads are not worn thin ...when worn to the stops they quit working. No buzzing wear indicators, no dash warning lights, no metal on metal grinding. Just a stopping distance that unexpectedly becomes three or more times as long. BTDT. Mine gave out at a school crossing with 6 people onboard. Never again.

64Avanti
12-14-2018, 11:47 PM
I googled those words. I get several "hits". I'm not sure which one you are referring to. The top one only talks about one difference...

"This basic design proved capable under most circumstances, but it had one major flaw. Under high braking conditions, like descending a steep hill with a heavy load or repeated high-speed slow downs, drum brakes would often fade and lose effectiveness."

https://www.edmunds.com/car-technology/brakes-drum-vs-disc.html

Do you have a link that would hopefully better define the term "better"?

What I don't get, is that if both systems on the same car/wheel/tire combo will generate enough braking force to slide the tires, what good is additional braking force?

Sliding the tires is not good for maximum braking. The drum brakes used on the front and rear of Studebakers without disc brakes are non linear. By that I mean the brake force is not proportional to the pedal force. The consequence is they are too easy to lockup. The disc brakes are linear and it is easier to control the braking at the limit to maximize the braking force and not slide.

spokejr
12-15-2018, 08:13 AM
As long as the pads are not worn thin ...when worn to the stops they quit working. No buzzing wear indicators, no dash warning lights, no metal on metal grinding. Just a stopping distance that unexpectedly becomes three or more times as long. BTDT. Mine gave out at a school crossing with 6 people onboard. Never again.

What stops? The disc brakes I've worked on could still function (albeit poorly) with the backing material alone proceeding to destroy the rotor, just like a bonded brake shoe would destroy a drum.

gordr
12-15-2018, 11:30 AM
If the piston is installed wrong, the stops won't work.

48skyliner
12-15-2018, 12:28 PM
"What I don't get, is that if both systems on the same car/wheel/tire combo will generate enough braking force to slide the tires, what good is additional braking force?"

The important difference for me is that with bigger, more modern disc brake systems I have always had a much more comfortable pedal pressure to get the braking I want in any given situation, so I am not testing my strength in a panic stop. I have put large modern discs on several cars, but I always use the front and rear brakes from the same car, so balance has never been an issue.
My 48 Champion has the complete brake system , including booster and master cylinder, from a mid 90s Nissan, 12 inch discs front and rear, and it has really excellent braking. 17 inch wheels are required to clear the calipers.

sals54
12-15-2018, 05:09 PM
The additional braking force is all about control. If your drums are fading with heavy use, its time to replace them with discs. I had 12" ventilated rotors on the front of my Coupe. Brakes from a 4500 lb car, used on a 3500 lb car makes for a non-fade brake experience.
Also, pumping brakes to come to a controlled stop is the way to go. I would MUCH rather have over sized disc brakes while pumping the pedal under an emergency stop. But that's just me.

Jessie J.
12-16-2018, 04:33 PM
What stops? The disc brakes I've worked on could still function (albeit poorly) with the backing material alone proceeding to destroy the rotor, just like a bonded brake shoe would destroy a drum.
You have worked on disc brakes. Most of us with a considerable amount of auto repair experience have worked on disc brakes.
So the question is whether these disc brakes that you've worked on were the original equipment STUDEBAKER Bendix/Dunlop disc brakes with built in stops to prevent the metal backing on the pads from ever coming into contact with the rotor?
Not discussing any other make, or manner of disc brake caliper that you may have hands-on experience with.
I was pointing out that the 1962-'66 Studebaker disc brake design is rather unique among American built vehicles, in having these built in pad stops to save the rotors from being scored and ruined by worn out pads.
When the other American automobile manufactures introduced their disc brake designs they did not employ any such pad stops in their designs.

Of course if you regularly inspected and changed the Studebaker pads BEFORE they wore down to that point, you would perhaps never even become aware that such stops are present, even if you have replaced dozens of sets of pads. I had no idea of this 'feature' back in 1969 when my accident occurred. There were no warnings of such in the Owners Manual.

I cannot say with any certainty whether Studebaker ever eliminated this feature. But in 1969 when my disc braked '65 Cruiser piled into a line of stopped vehicles at a children's school crossing (crossing guard carrying a STOP sign, and a dozen or so little children in the middle of a busy 3 lane highway) The brake pedal was high and rock solid HARD, but there were no sounds, no grinding, no pulling. Just the horror of unexpectedly being unable to stop. The brake pedal actually bent under the pressure I was applying.
It was my STUDEBAKER dealer and Service Department that hauled my Cruiser in, and that brought this design feature to my attention, at the time of replacing the entire front clip ...and rebuilding the brakes. (the original rotors were still just fine) I was ticketed for "Failure to stop in clear assured distance."

Read the first paragraph;
http://www.studebaker-info.org/Tech/brakes/dunlop/dunlopreb/diskbrakes07.html

Another feature is, that the pads/pistons will only extend a fixed amount, preventing a pad from wearing down to the steel. A worn pad can never contact and gall the rotor. When the limit is reached, the braking effect diminishes. So, if the original Avanti disk brakes start to pull, they may be telling you to change the pads.

Don't depend upon hearing any grinding noises, or experiencing any unusual braking. Those pads need to be inspected and replaced LONG before they wear to the metal. (they never will)
A total loss of front braking power CAN occur during a single stop, and without any warning.

Anyone that operates a Studebaker with original factory equipment disc brakes NEEDS to know this!
Lives may depend on it.

Jessie J.
12-16-2018, 07:24 PM
We will never know of the lawsuits Studebaker may have experienced over this 'feature' had they not so quickly folded. Every time I see a '62-'66 Studebaker or a Avanti with front clip damage, I wonder ...

rkapteyn
12-16-2018, 08:56 PM
Use Turner brakes.
Jim is an old time vendor with excellent support and a genuine nice guy.
http://turnerbrake.com

Studebakercenteroforegon
12-16-2018, 10:06 PM
We will never know of the lawsuits Studebaker may have experienced over this 'feature' had they not so quickly folded. Every time I see a '62-'66 Studebaker or a Avanti with front clip damage, I wonder ...

Given your experience, you must have had a system that someone installed the pistons at 90 degrees from where they should have been. There is no “stop” when they are correctly assembled. In fact, when the pads get too thin, the first failure is that the caliper cylinders will start leaking since they are at the end of their travel. That is why you are supposed to replace the pads when they are worn to about .250” thickness. (Earlier the number was something like .220” but even that was increased.)
I have bought cars that had the caliper pistons installed 90 degrees wrong. What I would find would be the lower sheet metal “bridge” would get pushed in to the rotor, thus wearing a bad groove in it. I also wonder why someone would install them incorrectly. It seems quite evident how they should be assembled.
I have driven tens of thousands of miles with factory disc brake equipped Studebakers with total confidence. Not to mention that this system was successfully used on many European cars and models of Datsuns and Toyotas. No need to think something was “wrong” with this early disc brake design.

Jessie J.
12-17-2018, 01:35 AM
I inherited my Yukon Gold '65 Cruiser as a HS graduation gift from my elderly and retired uncle. Uncle Herb had 'special ordered' it and had to wait for it to be built and delivered. In the 4 years of ownership by a very sick and frail senor citizen it had accumulated less than 30,000 miles in 1969 and certainly had never been serviced by any other than my uncle's Studebaker dealer and long time personal friend, Mr. Louis (Louie) Sipka of Sipka's Service in Bannister Michigan. Uncle Herb was adamant about ALL services being performed by Sipka's Authorized Studebaker Service... So much so that he would not even so much as permit me to give it a wax job. That -had- to be done with Studebaker's own brand of 'STUDEBAKER Haze Cream' sealant, applied by Mr Sipka himself in his Service Department.
Myself also having been introduced to and acquainted with Mr Sipka, and being extremely committed to Studebaker in all of its aspects, all required service during my ownership (at that time only a few months) had been performed exclusively at this Authorized Studebaker dealership Service Department from the day of its Delivery.
With such few years in service, and at that ultra low mileage it is extremely unlikely that the caliper cylinders had ever been disassembled since the day that they were installed on the Studebaker factory assembly line.

The quotation posted in red in my above post comes direct from Bob Johnstone of Studebaker-info.org Its his take.
You are welcome to debate with him how Studebaker brakes were intended -by Studebaker Engineering- and their original -as assembled- configuration, to be assembled and function.

I had a bad experience in a almost new Studebaker in 1969. I was driving in Owosso Michigan, with 5 family members and myself onboard. My brakes had been functioning perfectly up to this last moment before the crash. No one was riding along under my car to turn the brake caliper pistons 90 degrees.
Mr. Sipka, a Factory trained Studebaker technician was the FIRST one, in 1969 to tell me that this 'feature' of Studebaker's disc brakes was why my vehicle had failed to stop. Bob Johnstone's above statement presents the same. "the pads/pistons will only extend a fixed amount," ..."When the limit is reached, the braking effect diminishes." Nothing about cylinder leakage being the "fixed" "limit". Which in any case would be a extremely stupid and dangerous method of limiting pad wear or preserving the rotors.
What any other foreign automobile manufactures may have did, is not indicative of what STUDEBAKER Corp. was doing in 1965.

Following the accident only the worn out brake pads were replaced, brake operation returned to normal, and the high hard pedal condition was relieved (no fluid leakage) My Studebaker's brake calipers never leaked a drop of brake fluid during all my years and tens of thousands of miles of ownership.
Owning several newer vehicles, I finally sold the Cruiser around 1975. Always garage kept and cleaned and waxed almost monthly, it still looked as new.

Although I have since owned about a dozen Studebaker's (2 '64 Daytona's and a '62 Lark presently) I have never since owned another operational disc brake equipped Studebaker.
I may not know exactly WHAT went wrong with the brakes on that day, other than that the pads had worn excessively, but I see no reason to take the unneeded risk of it ever happening again.

gordr
12-17-2018, 10:33 AM
One thing to remember here, those disc brake Studebakers were all equipped with single-circuit master cylinders, and the rear brakes ran off the same hydraulic pressure as the front ones did. If the pads hit the stops, front brake effectiveness diminished rapidly, but the rears should still stop the car, albeit less quickly. That was the clue to have the pads changed. Of course, if the car was getting regular service in a dealership shop, the mechanics there should have been keeping tabs on front pad wear. The brakes don't go from "working normally" to "no brakes at all" in one fell swoop. There would be a fairly rapid increase in pedal effort, often accompanied by a pull to one side, as one front wheel lost braking effectiveness before the other.

Jessie J.
12-17-2018, 12:20 PM
It was an attempted 'panic stop' in response to a city traffic situation. The vehicle was fully loaded with passengers, and has just traveled 40 some miles that day to reach that point.
A clear dry sunny afternoon. Speed limit was 45 mph. Because of the line of traffic, the crossing guard and crossing children were entirely hidden from view.
The vehicle approximately 120 ft in front of us stopped abruptly. Attempted braking, the Studebaker initially slowed and then rolled on, closing the distance until collision, taking up approximately 3 times the length of any of our preceding stops.
There were no noises, no pull to either side, and no amount of increased pedal pressure sufficed to further slow the vehicle.
Impact was at 4-5 mph. Badly buckled hood and fenders and no brakes rendered the vehicle totally inoperable, and it was towed into a nearby parking lot.
Sipka's Studebaker service was immediately called, and soon arrived with his 1948 Studebaker M-16 tow rig.
The Cruiser was towed back to the Bannister Michigan Studebaker dealership where Mr. Sipka ordered the parts and worked on repairing and repainting it, for the next month or so, also providing us with a '63 Lark loaner for the duration.
Mr Sipka had many years of experience and did an excellent and virtually undetectable repair job. The brakes were fixed, whatever that took, and I never again experienced any trouble with them.
Owner of the rear ended vehicle showed up at my house a few days after the accident, yelling and claiming whiplash, and threatening a lawsuit. but never heard from him again.

From that point I went on to modifying the drive train quite extensively, first with the addition of a Weiand Hi-Rise & AFB , custom bent dual exhausts, and a Duntov cam. Followed that up by converting from the FoM to a T-10 4 speed and 3:54 TT obtained from my friend Louie Sipka. Anyone can tell me that it didn't happen ..but I and my wife of 50 years were there.

Jessie J.
12-17-2018, 01:29 PM
There is no “stop” when they are correctly assembled. In fact, when the pads get too thin, the first failure is that the caliper cylinders will start leaking since they are at the end of their travel. That is why you are supposed to replace the pads when they are worn to about .250” thickness. (Earlier the number was something like .220” but even that was increased.)
Not at that time, and certainly not now, is it reasonable to expect an owner unfamiliar with the idiosyncrasies of this brake design, to know that their brakes would weirdly fail to function with a quarter inch thickness of the pads still showing.

"the pads/pistons will only extend a fixed amount," ..."When the limit is reached, the braking effect diminishes." Nothing about cylinder leakage being the "fixed" "limit". Which in any case would be a extremely stupid and dangerous method of limiting pad wear or preserving the rotors.
It boggles the mind to believe that Dunlop/Bendix and Studebaker would design a system that intentionally intended and depended upon the calipers springing a brake fluid leak as a means of preserving brake rotors, or that government standards would even tolerate such a compromised design.
While pad material remains, there is no sensible engineering or design reason why the calipers should ever be leaking any brake fluid. No other disc brake caliper I have ever encountered has ever depended upon leaking out the brake fluid as a method limiting pad or rotor wear.

Do you have any Factory literature verifying as fact that this system was intended to leak fluid once pad thickness reached .25" ?

studegary
12-17-2018, 09:00 PM
After reading through this, it now appears to me that you experienced complete brake loss due to a failed master cylinder or a leak in a brake line somewhere and not a failure of the disc/caliper assembly itself.

Jessie J.
12-18-2018, 12:12 AM
After reading through this, it now appears to me that you experienced complete brake loss due to a failed master cylinder or a leak in a brake line somewhere and not a failure of the disc/caliper assembly itself.

Would that make the brake pedal remain high and hard? It was 49 years ago, and I did not perform any of the repair work, for which the final invoice was quite extensive,(likely more than the wholesale value of a undamaged '65 Cruiser at that time) to the best of my recollection my insurance covered the entire cost. That is likely why I cannot recall minor individual items replaced.
I do however remember that one of the first things I and others did in the parking lot immediately following the collision was to get down on the pavement and check the calipers, rear drums, and all the lines for any signs of fluid loss, all was clean and dry.

Upon reviewing all of this, and given that the calipers showed no signs of leakage, I tend to agree with Gary that the brake failure I experienced was either in the master cylinder, booster, or possibly the under dash linkage, not likely the latter, as if that had been the cause I'm sure that Mr. Sipka would have made a point of bringing such to my attention. No asking Mr Sipka now as sadly, he passed away decades ago.

I still have reservations about the Bendix caliper design, as it certainly does not seem right nor good engineering for the piston seals to leak before the friction material wears away to the metal, and maintaining positive braking action until there is consistent loud audible warning, either by provision of 'wear indicators' or the grinding of metal on metal.
At my age the matter is quickly becoming moot, the drum brakes I have, if well maintained will continue to do their job well enough.