Brakes: Studebaker Avanti brakes

[Hawklover]

So here is an odd ditty as of late:-(................as of late when I wish to take the Avanti out of the storage garage and attempt to back her out, the rear brakes are locked up!.........putting the car in reverse (4-speed) and feeding gas clearly exhibits a binding situation..........I have to feed lots of gas and slip the clutch to move in reverse. Once I get the car in first to move forward I have no binding situation. Note that the parking brake is free and not binding in any way. This is an intermittent brake situation. Just wonder what you all think is causing this malady? Once I get the car in reverse the situation is not repeated for the most part. Only after the car has been sitting in the garage for a week or so.

[Topper2011]

Is is possible the parking brake cable is sticking in the housing that attaches to the backing plates? My 1998 Chevy C2500 does this once in a while as it sits a lot. A bit of rocking frees it up.

[firestoper 25]

Good grief, what a parallel universe.....my Avanti - 631089 has the opposite end locked up...the left front disk is stuck! So I am reading up on the specifics to inspect & repair. And yes I have new Cuni lines, dual master cyl.,SS flex's , self bleeder's , etc., so this is going to be an eternity getting this done! Ugh.

[StudeRich]

Both of you could check for Pressure build-up in the Brake System.
A Plugged vent on the M/C, insufficient Free Travel on the Linkage and Pedal, wrong length M/C Push Rod, etc.

OR, it could be as simple as a seldom driven Car having a stuck Wheel Cyl. or Caliper Piston.

[Hawklover]

Both of you could check for Pressure build-up in the Brake System.
A Plugged vent on the M/C, insufficient Free Travel on the Linkage and Pedal, wrong length M/C Push Rod, etc.

OR, it could be as simple as a seldom driven Car having a stuck Wheel Cyl. or Caliper Piston.

Rich I would suspect that use is the issue because none of your other suggestions apply. Its just a RPITA, I hate when "S" happens:-(

[Hawklover]

Why is this malady only presenting itself when the car is put into reverse, and never in forward?

[Hawklover]

Good grief, what a parallel universe.....my Avanti - 631089 has the opposite end locked up...the left front disk is stuck! So I am reading up on the specifics to inspect & repair. And yes I have new Cuni lines, dual master cyl.,SS flex's , self bleeder's , etc., so this is going to be an eternity getting this done! Ugh.

Be aware that many years ago I did in fact have a situation where one of my front wheel brakes was really binding. Turns out we took the drivers side caliper apart and there for all to see was the problem:-(................a well known Studebaker vendor sold me ss sleeved units..........one of those units had a mushroomed over brake pad attachment "tit"........thankfully the shop was able to un-mushroom that "tit" and re-fit the pad. Like magic, no more brake drag. So please give this fact some consideration:-)

[Jeffry Cassel]

Had same thing happen in 61 Hawk. It was the mc relief valve that was defective. That would not apply to a disc brake car. You are going to need to jack up the rear end, pull the hubs, check the emergency brake cable, and rebuild or possibly replace the wheel cylinders. I suspect corrosion and resultant binding between cylinder wall and piston. is to blame. Replace cylinders if pitted. (If it is a stuck eb cable, that would engage the brake in reverse but not so much going forward. )

[Hawklover]

Had same thing happen in 61 Hawk. It was the mc relief valve that was defective. That would not apply to a disc brake car. You are going to need to jack up the rear end, pull the hubs, check the emergency brake cable, and rebuild or possibly replace the wheel cylinders. I suspect corrosion and resultant binding between cylinder wall and piston. is to blame. Replace cylinders if pitted. (If it is a stuck eb cable, that would engage the brake in reverse but not so much going forward. )

Many thanks Jeff, some excellent suggestions! Just so happens yesterday I ordered two new rear wheel cylinders, this despite the fact I think I have two new rebuild rubber kits. I might as well put shoes on as well, I was most fortunate to get a set of riveted lining (not a fan of bonded)......LOL.........yesterday she only "stuck" one time.........the rest of the day no binding in reverse;-) If it is the cable, why does it present intermittently?

[firestoper 25]

Thanks for the 'mushroomed over' tip ! Seeing as my cars build date is 60 years ago,no telling what odd changes / breakages I will find.

[Jeffry Cassel]

It is intermittent because it is rusty on the inside--between cable and sheath-- and it is crying out for some 3 in 1 oil. When you work it it loosens up (temporarily)

[bezhawk]

SS sleeves on the caliper have NOTHNG to do with the PISTON. If the piston is damaged where the pad slides over the piston "button" then it isn't the fault of the bore of the caliper! I would say 50% of the pistons in the calipers I take apart are already damaged when I do brake overhauls.

[Hawklover]

SS sleeves on the caliper have NOTHNG to do with the PISTON. If the piston is damaged where the pad slides over the piston "button" then it isn't the fault of the bore of the caliper! I would say 50% of the pistons in the calipers I take apart are already damaged when I do brake overhauls.

Brad I will soon be doing a full brake job, can you tell me where I can get that special tool to re-set the pads? Please tell us how the pistons are damaged?

[StudeRich]

One of the things Brad is talking about is, the "Nail Head" on the Pad end of the Pistons.
Post 7 and 12 are related to the same condition.

[Hawklover]

Rich I am attempting to find the tool to re-set the pistons to accept the new pads.

[bezhawk]

A small pry bar will suffice. just remove the upper retainer and leave the old pads in place while prying between the rotor and old pad. They retract as easily as any caliper. By leaving the old one in place you protect the retaining head on the piston. Make sure the new pads fit well. Some have to be filed or sanded so they don't lock up n the caliper bridge. Many are oversize slightly.