1955 Series 62 sedan brake problems

[MickeyCaddy]

Hi! I'm new to this forum, and glad to be here. Such a wealth of information!
I've been loving my new 1955 Series 62 sedan, especially since I got 5 new American Classic bias-look radial tires. I drove it for 4 days, putting on about 150 miles, with no issues; just fun.
Then on the 4th day, I set out on a journey of 15 miles, each way. It was hot in LA, around 90. As I started home, I noticed right away the car seemed sluggish, as if dragging. After a few minutes it began bogging down in 4th gear, and I had to drop the Hydramatic into 3rd just to maintain forward motion. Also, the brake pedal (power brakes) became as hard as a rock. To make it up a hill that's normally not a problem I had to kick it down and keep it floored...
When I had to stop at a stop sign, the car froze, immobile. 15 seconds later the radiator overflowed, green antifreeze flowing down the street...it was very depressing.
I had a flatbed tow it to my mechanic, who's worked on it for a week. The brakes had seized up; the extra energy needed to move the car caused the engine to overheat, and the cork seal on the radiator cap was deteriorated and couldn't hold the pressure. That's why she boiled over; I've had the radiator rebuilt and a new cap installed.
A new master cylinder and wheel cylinders have now been installed, and the system bled per the unique bleeding procedure; but the brakes still drag, then lock up. The HydroVac was temporarily bypassed; after that, the brake pedal was actually easier to push and more responsive than it was with the boost; but after ten minutes of driving, the dragging began again.
It's now been determined that it's the front brakes that are locking; the rears seem OK. But my mechanic is at a loss, and I'm of little help...this is my first classic car. I have a fair amount of automotive knowledge and have been around cars all my life, but I have only a limited amount of self-taught wrenching experience, which is why I have to rely on my mechanic.
If anyone has any ideas I'd be eternally grateful...can't stand not being able to drive my beauty. Thanks in advance!
Below is a picture of my baby..."dead in the water".

M Chanslor

[Walter Youshock]

Happened to me.  Replace EVERYTHING.  All 4 wheel cylinders, brake return springs, shoes, have the drums reground or replaced depending on the warpage, replace all 3 flexible lines,  have the master rebuilt and send the booster out for a rebuild.

The Hydro vac booster is "wet" in that it forces fluid from the master cylinder into the booster which triggers the boost.  Problem is its vented to the atmosphere which means it is also constantly sucking moisture.  The only way to be safe is start over.  It is also the o ly way you can switch to synthetic fluid if you choose.

This happened to me on the PA Turnpike.  The car almost burned up.  All 4 hubcap centers melted and the front passenger wheel got so hot it blew the tire.  I bleed the brakes every year now.

[MickeyCaddy]

OMG â€" that's scary! You were lucky to still have a car after that happened.
In the last two weeks, new wheel cylinders and a new master cylinder have been installed. Your suggestion to change the flexible lines makes sense, too.
I'm unsure about how to deal with the HydroVac; there must be some issues there, as braking was more responsive and easier to modulate after bypassing it; but the brakes still locked up after 10 minutes of driving.
I'm OK with getting a new HydroVac, but the main concern is that we can't seem to get a handle on the lock up issue; and now, it's been determined that only the front brakes are dragging and locking.
Thanks so much for your advice; I'm passing it on to my mechanic now.

[Eldovert]

Sometimes the brake hoses can come apart on the inside..a flap of material can act like a one way valve allowing you to apply pressure but not allowing  the brake(s) to release. I had this happen on a mid sixties Chev wagon.
Cheers,Pat MacPhail

[Walter Youshock]

Exactly.  Corrosion blocks the lines or damages them.  Think ARTERIES.  blood can't flow back and forth.  Guess what-- you're having a brake attack.

No WY is bypassing the booster a good idea.  These cars are big, heavy, powerful and need all the help they can get to stop.  STOP should be every old car owner's priority after "run", not "go".

The Hydro vac wasn't the greatest power assist but it's a lot better than nothing.

[MickeyCaddy]

I agree totally on not expecting the HydroVac to remain bypassed; it was done only as a temporary experiment. What surprised me was that the brakes performed better without it. The pedal had always been hard, and just before the 1st lockup issue, even harder. Sort of like they were on or off; nothing in-between. After bypassing the HydroVac, they felt like a set of normal, non-power-assisted drum brakes on a 1950s car. For the first time, I could actually modulate how much braking power was applied.
So I guess there are several issues here. If the brakes work better without the HydroVac, then there's definitely something wrong with it. And since they still lock up even without the HydroVac, that's a separate issue, possibly caused by internal damage to the lines.

[MickeyCaddy]

Can anyone recommend a reliable mechanic in the Los Angeles area who knows mid-50s Cadillac brakes and can be trusted to fix, in a timely manner, these brake issues I'm having? My mechanic has been working on this for 2 weeks and the car still isn't drivable.

He just told me he spent all day today on it, but he hasn't been able to fix it â€" the brakes are still locking up. I've decided it's time to cut my losses and get this handled properly.

Got my fingers crossed â€" everyone on this forum has already been extremely helpful. Many thanks to you all!

M Chanslor

[Jay Friedman]

I would do everything that Walter and Eldovert recommended, replacing the flexible rubber hydraulic lines in particular.  In addition, I would replace all the steel lines with stainless steel lines which can be bought from Inline Tube and other firms.  Yours may be corroded internally and, like the flexible lines, are not letting the brake fluid sufficiently withdraw and the brakes to release. 

Personally, and it's just my humble heretical opinion, you'd be better off without the Hydro-Vac in operation.  As you said yourself, "the brakes performed better without it".  My '49 has no power assist whatsoever, and I have no trouble whatsoever stepping on the brake pedal with moderate pressure and with the car stopping just fine.  (I think Cadillac's introduction of these power features in the '40s and '50s to some extent were selling point solutions in search of problems.) 

[Caddy Wizard]

It is the hoses -- replace them and all will be well.

[Caddy Wizard]

Here is what I posted to you on the 54-56 forum:


Brake hoses (not the metal lines) can cause this and if the brake system was working fine for a while before experiencing this, bad rubber hoses would be my first suspicion.  When the hoses get old, they can get restricted internally and will allow the high pressure (1200psi) to go out to the wheel cylinders, but will not allow all of the pressure to release when you let off the brakes.  So a smallish amount of pressure remains in the lines and causes the front wheels to lock up.

If the front wheels only were locked up, it is hoses.  If all four wheels were locked up, something else is at work (bad master, booster, mis-adjusted push rod, etc).


Oh, one more thing -- sticky wheel cylinders can act this way too.  You see this sometimes in a car that has sat up for a while and the wheel cylinders have corroded inside (practice tip: sleeve the wheel cylinders and master with brass or stainless and be sure to flush the brake fluid every couple of years).

[dplotkin]

I've been loving my new 1955 Series 62 sedan, especially since I got 5 new American Classic bias-look radial tires. I drove it for 4 days, putting on about 150 miles, with no issues; just fun.
Then on the 4th day...

Mickey:
The posts from our friends above all have merit and might be good clues. But the most common reason for your problem is a maladjusted master cylinder pushrod. That you have not owned this car long gives rise to my suspicion that someone in the recent past has tried to correct a "low pedal" by re-adjusting that rod instead of finding the real problem, which is usually bad wheel cylinders or booster. The rod adjustment is critical, only a thread or two is the difference between motoring bliss & a nightmare. What happens is the brakes drag, the longer the trip the hotter they get until finally the car cannot overcome the friction. Tough on engine and especially transmission.

Find a brake guy older than 50 and bring him the car & the shop manual. At this point the shoes are glazed and the fluid is spent. I would rebuild the booster and change the cylinders along with the rubber lines as per advise above. Then adjust the pushrod exactly as per the shop manual. After that change the transmission fluid.

ps. I own a 56 with a completely different system and I'm by no means an expert on the 55, but I've been down the road you have before....

Dan

[walt chomosh #23510]

Micky,
  I'm with Art in re guards to replacing the flex hoses going to the brake backing plates. I've seen this happen a number of times with various cars. (internally deteriorated)  Also,I've experienced the same problem by not having enough "free play" in the pedal to MC.(had a Harley rear brake lockup on Highway66,and couldn't move the bike off the highway!) I also had my 55 lock due to insufficient free play.....walt...tulsa,ok

[dplotkin]

  Also,I've experienced the same problem by not having enough "free play" in the pedal to MC.(had a Harley rear brake lockup on Highway66,and couldn't move the bike off the highway!) I also had my 55 lock due to insufficient free play.....walt...tulsa,ok

Free play is what is adjusted via the pushrod I discussed above, in case you were unaware....

Dan

[MickeyCaddy]

This is all great advice â€" thanks everyone! I'm having a meeting with my mechanic tomorrow (Tuesday); I'll let you know what happens...

[Jeff Rosansky CLC #28373]

I had replied to you on the other site..... But it is the front? I thought it was the back.
Jeff

[MickeyCaddy]

Jeff, I remember you from the other forum site â€" thanks for your advice. I thought it was the back, and posted that. My mechanic thought so too.

This past weekend, after a lock up episode, and based on advice I've received, I insisted that my mechanic put the car on jack stands and try to spin each wheel in order to be exactly sure about the situation. He reported back that it was the front wheels that had the problem.

Which I think indicates to me that he spent the last two weeks assuming it was a rear wheel problem; which may have a lot to do with why I still can't drive the car.

[MickeyCaddy]

Art, thank you, too, for posting on both forums. I really appreciate it!

[savemy67]

Hello MickeyCaddy,

Based on your posts, I am not sure why you had to insist that your mechanic raise the car and spin all four wheels.  I would have expected a mechanic to look at the entire brake system given the magnitude of the symptoms.  Maybe that is why you are looking for another mechanic.

Since Cadillac did not introduce a dual-circuit braking system until 1962, any brake system prior to 1962 should be looked at in its entirety.  All the advice above is good, but you may want to consider a holistic approach to resolving your brake issue.  Your mechanic should recognize three sections to your '55's brake system - mechanical, hydraulic, vacuum.  Each section should be checked.  Some sections involve relatively easy repairs - wheel cylinders, hoses, return springs, etc.  The vacuum section is more complex, but the vacuum section is irrelevant if the mechanical and hydraulic sections are malfunctioning.

Respectfully submitted,
Christopher Winter

[carguyblack]

Walter, if you're still looking at this post, this one's for you.
I have two 56 Cads and was wondering if you'd recommend a complete brake bleeding/flush every year? I drive these things less than a couple hundred miles a season but I had thoughts to do this, too. Talked myself out of it "'cause it ain't broke" (yet)
What say you?
Thanks for the advice,
Chuck

[DBDB]

I would first see if i have enough free play to the master cylinder.I had the same problem with my 1950 cad and after i gave the master cylinder the play it needs my problem was solved .then see if the flexibles are free ( you have to be able to blow through them with your mouth )if they are free the brakes cannot lock up normally unless something is not as i should be .