'55 Olds Master Cylinder Was Leaking Down,So We Ordered New Kit And Rebuilt Booster And M.C. Brakes Feel Fine ,Stops Great,and No More Leaking Down. On next Trip right Front Brake Locked up Completely,Ruined shoes And Drum. replaced Damaged Parts and Wheel Cylinder Kits,Bled Brakes And Everything Seemed fine Until I Drove 10 Miles And left Front And Right Rear Brakes Started Smoking. What Could Could Be Causing Brakes To Be Applying,and It's Not Always The Same Brake Locking Up. Called The Gentleman In Florida That Rebuilds Treadle Vacs And He Said It Could Not Be In Booster/M.C. Also Replaced Brake Hoses Any Ideas greatly Appreciated,Larry

 

Is it a Bendix or Moraine unit? Did you regularly drive the car before this happened? Did you replace all the brake hardware/shoes/lines AT THE SAME TIME? Did you bench bleed the master cylinder? I thought he recommended that before you put it on the car ( if its the same rebuilder I'm thinking of ) Some things you described could be grease or brake fluid on the brake shoes, mis adjusted brake shoes, maybe primary/ secondary shoes installed backwards?? bad return springs. Sounds strange that all three wheels went bad on you, and not just one

 

Thanks 59-59-59. It's The Bendix Unit. The Car is Only Driven About 1000 Miles A Year,but I Do Try To Drive Every 2to3 Weeks Year Around.we Did Not Replace All Hardware,only The Ones On Right front Wheel That Got So Hot But We Visually Checked The Others. As for Bench Bleeding I'm Pretty Sure My Mechanic Did,He Is Very Thorough. Will Recheck Everything Outside M/C first.If All Checks Good,could Be residual Valve Or Something Else
Back In M/C. thanks For Your Concern, Larry

 

On my '69 GMC p/u I had the rear flex line that goes from the frame to the axle too close to my exhaust...so when the brakes were applied they worked OK, but when released, the fluid was trapped at the damaged area by the exhaust pipe and the rear brakes would drag. Flex hose did not leak!

 

Thanks, It Won't Be Any Trouble To Re-inspect All The Hoses. Thanks For Your Interest.
Larry

 

If the rubber hoses to the wheel cyl. is old, it may have collapsed inside. There are more than one layer of rubber and if the inside layer comes loose, it can collapse and lock up the wheel cyl. without you being able to see it. Best to replace all the rubber lines! BEEN THERE; DONE THAT!!

 

While adj. mine so the brake light would go off, I got it too tight and it held the flluid in the lines and brakes stayed on and heated up. Took about 4 or 5 applications to lock up. Backed off and adj. my brake light sw. and now it works fine.

 

How do you bench bleed a treadle vac? It is not like a regular master cylinder. I just sent mine out for rebuilding and it should be back in a couple weeks.

 

Were the hard brake lines flushed or replaced since you have owned the car?

 

I have never bench bled mine out of the car, took a little while to get all the air out but not much of a problem....Tedd

 

Thanks Tedd. I don't believe there is any way to bench bleed a treadle vac. Did you have yours rebuilt and if so, who did it.

 

Yes twice, I'can't remember on the first go around (13 years ago) but on the second rebuild Steve Larsen (Larsen Automotive) in Chico Ca. did it. He may have done the first or had it sent out, a lot was going on at that time as the car was all apart and parts were coming and going dayley...Tedd

 

I sent mine to Karps Power Brake Service in Upland, CA. He does them himself and puts a stainless sleeve in the master cylinder. Not cheap, a little less than $500 by the time I pay the freight both ways. But, it is not something I can't take a chance on. I will let you know how I come out.

Thanks Tedd

 

Mike, Just Wondering If Your's is Still Working OK, And Once You Have It Properly Adjusted Does The Pedal Now Sit Directly On Top Of The Booster/Master Cylinder Rod Or Is There A slight Clearance Between These Two. Thanks For A Return Reply. LARRY

 

Larry - I have a Moraine unit in mine. I sent it and the wheel cylinders to White Post Restoration in Virginia. They lined all the cylinders with brass sleeves. This was around 10 years ago and I have had no problems. They have a lifetime guarantee on their work.
Rick

 

Hi Larry,
how is it going with your Brakes?
What was finally causing the Brakes applying in your case?
Would be great if you tell. I’m working on the same problem (1954 BTV)

Thanks
Monaco

 

Hi Monoco,we went back and replaced the residual check valve,took another look at the compensating valve,and in the process readjusted the brake light switch at the pedal.Sorry to say but didn't recognize a particular problem,but so far it's not heated up since.I've not been on any long trips,but it seems to be okay! Will re-post if a problem arises. Larry

 

Thanks Larry,
I replaced the springs of the brake shoes, but I suppose the most important thing is to adjust the brake light switch.
Brakes are working perfectly since.

Have a nice week,
Monaco