Disc Brake Conversion

[Jessie J.]

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]

Use Turner brakes.
Jim is an old time vendor with excellent support and a genuine nice guy.

http://turnerbrake.com

[Studebakercenteroforegon]

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.]

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]

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.]

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.]

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]

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.]

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.