Brakes

[NHcamper]

I just took my car out for a short drive and when I returned the front brakes are just about locked up.

I drove this car 2700 miles on no booster pretty much no brakes. Restored vacuum to the booster and power brakes were working just fine. Since I had power brakes I have only taken the car around the block, today was the first time I drove it over a mile.

My question is do you think the calipers are sticking now because the power booster was not working for so long and the car was only driven with caliper not being activated and now that they are operating under normal conditions this is what’s causing them to not release. If so is it cost effective to rebuild them or should I look for replacements, it’s not in the budget to do the turner conversion right now. 

[studegary]

What is locking up - one wheel or both?   With the limited information, you may have a brake line, probably a flexible line (but they are separate - side to side), that has died of old age (collapsed/restricted internally, not allowing release of pressure).  It may also be the (brake) pistons sticking.  Did they release gradually?  How long and how much braking was your "short drive"?  If you remove the vacuum from the booster, do the brakes work "normally"/release again?    

[NHcamper]

I’ll take a good look at it tomorrow and post what I find. 

The short drive included several stop signs but no hard braking, felt consistent and even. Just thinking if the car wasn’t driven with properly functioning brakes for an extended time it might be best to rebuild the calipers replace the rubber lines and double check the rest of the braking system.

[Gunslinger]

Before going into too much with your current btakes, have the rotors measured to make sure there's enough metal left for safety.  If the rotors need replacing plus new hoses, caliper rebuilding or even new calipers, you're already in the money area of the Turner Brake Kit.  You would be far better off doing the conversion.

[NHcamper]

Checked cat this morning brakes fully released. Took it out for a ride almost the same route as yesterday no problems. I’m going to change brake fluid first, who knows how old it is and still going to check everything and go from there. I plan on doing the brake conversion ASAP just for future reliability. Thanks for the suggestions and support. 

Not related to brake issue. I was at the gas station and an older gentleman asked if I would be interested in selling the car, I replied not at this time. He gave me his card and said give me a call if you decide you want to sell it. If I get the car fully functioning maybe I will put a price on it and go on the hunt for another one LOL.

[WayneC]

Most likely reason is a vacuum leak in the power brake booster unit. I had that problem (front brakes dragging) back in the 1980's with my '71 Avanti but I can't remember how I determined it was the booster.

One possible way to test is to find the vacuum hose from the intake manifold to the booster unit, disconnect it at the manifold and use a hand vacuum pump (with gauge) to apply vacuum to the booster vacuum hose and see if it holds the vacuum.

I sent the booster to "Booster Dewey" ... http://www.boosterdeweyexchange.com/dev/

Edited September 23, 2018 by WayneC

[NHcamper]

New booster, master cylinder have driven about 25 miles today hard stops light stops holding brake for five minutes on a hill. Did check booster again no leaks. Going to drive it to work 80 miles round trip. Making sure my AAA is up to date lol.

[wwundt]

If you have replaced the booster and the master cylinder it is crucial that you have also adjusted the length of the rod between the booster and the master cylinder.  If it is too short you will not get a full stroke which will not give you maximum braking; if the rod is too long you will not get a full stroke either and the piston cannot return back far enough to release pressure and your brakes will lock up.  The shop manual describes the correct procedure to adjust the rod.

[RINGMASTER]

After 10 years in storage working on getting my 1980 Avanti road worthy.  Any idea what rear brake shoes are required and where to buy them?  Also what is a Turner Brake Kit?  Thanks for your effort!

[Gunslinger]

Contact either Jon Myer at Myer's Studebaker or Dan Booth at Nostalgia Motors.  Either can hook you up with the correct rear brake shoes and any other brake parts you might need.

The Turner Brake Kit converts your Avanti from the original Dunlop/Bendix disc brakes to modern vented rotors and larger disc ads with the appropriate calipers and other parts.  Original brake parts are quite expensive...especially if you need new rotors which is quite likely.  The cost of the conversion kit is on a par with the cost of replacement/reproduction original parts.  You can buy the kit direct from Jim Turner...other vendors carry them but it's less expensive direct from Jim...who by the way is a great guy.

Another advantage to converting to the Turner kit is that your old parts can be resold to others who might be purists...this will help offset the costs of the conversion.

[Avanti83]

Gunslinger spelled it out well. Just for the record, this is the Turner kit on my 74. If you decide to order one, also get Jim's SS flexible brake lines. 

I recall the kit is late 90's S10 4X4 calipers and Ford rotors. I just replaced a caliper on mine last month and it cost $22 exchange at Oreilly's with bolts and banjo bolt.

[RINGMASTER]

Gunslinger & Avanti83 thanks for taking the time to help me

[mfg]

On 10/16/2018 at 2:13 PM, RINGMASTER said:

After 10 years in storage working on getting my 1980 Avanti road worthy.  Any idea what rear brake shoes are required and where to buy them?  Also what is a Turner Brake Kit?  Thanks for your effort!

The national brake rebuilders part number on those rear brake shoes is ..."228".....And they are usually available 'off the shelf' at any of the larger chain auto parts stores.

They are common to '69-'82 Chevrolet 1/2 ton pickup truck rear brakes

The specs are...... 11" in diameter, and 2" wide....Hope this helps!