1950s 1954 series 62 braking issue

[Julien Abrahams]

So today I drove my '54 and took it on a 50 mile trip. Car performed fine. Parked it and after about an hour or 2 took it to drive home. On the way home I had to make a hard stop while going slowly (say 5 miles an hour). No problem. Then drove the car for about 10 miles. When I need to brake, the brake pedal almost went tot the floor and the car was hard get to a stop. Little braking power. Tapped the brakes and everyhting seemed to return to normal. Drove through town in stop and go traffic. No problems. Then drove for about 5 miles again and when I had to come to a stop near my garage, the same thing happened: pedal almost to the floor and little braking.
Put the car in the garage and just checked the wheels to find the right rear pretty hot and the others only luke warm.
What is going on? Last year I renewed the rear brake shoes, cylinders and hose. The brakes are adjusted per the shop manual. It seems as if something happens when braking hard that causes the rear right brake to drag, get very hot and create an air bubble in the brake cylinder(?).
I will have a look at the brake shoes tomorrow, because I think I smelled burnt brake shoes. 

[PHIL WHYTE CLC 14192]

That really is an odd problem. Pedal to the floor would indicate a leak. Has your fluid level dropped?
Then the rear wheel getting hot because of the shoes binding is another odd one, initially I thought a faulty brake hose but there's only one hose to the back axle so that would affect both rear wheels.
For no obvious reason the power brake unit keeps coming to my mind🤔.
I think I would first check if it's losing fluid.
If it is then find the source of the leak (it could be in the power brake unit).
If it isn't I would jack the car off the ground and take all the hubs off and check everything is moving freely including the parking brake mechanism (if that's sticking on one side that would be the rear wheel problem).
Then redo the major brake adjustment procedure as per the manual.
Good luck.
Phil

[tluke]

Might be the power brake unit. Since you mentioned having replaced wheel cylinders and hoses etc.
1) Make sure the power booster was bled correctly. There are two bleeder valves on the unit. The first one to bleed is the lower one near where the brake line exits the booster unit going to the the wheels. Then bleed the one on the control valve on the top of the unit. Then re-bleed all the wheels as you would normally.  Unlike the TreadleVac (used '56 and later) which converts the mechanical force of the pedal to control vacuum, the 54-55's uses brake fluid at that control valve at the top inside the unit to control how much vacuum is released to assist in braking. Air in the fluid in that portion of the booster would prevent or diminish the vacuum reaching the diaphragm.
2) If you've ever replaced the master cylinder (or HydroVac unit) make sure you have the correct ones. '54 has the ball check valve in the M/C. '55 has the check valve in the HydroVac unit. There's just one '54 M/C but there are two different M/C versions in '55 - i.e the same one used in '54 is also used when the '55 has no power brakes and a different one with NO check valve in cars with power brakes (i.e. booster has the check valve). Sometimes online outlets sell the same M/C for '54 and '55. A '55 M/C for power brakes on a '54 would mean no check valves in the system. Or, if the '54 HydroVac had been replaced with a '55 unit sometime over the last 70 years you would have 2 check valves. Check valves control how much fluid is left in the brake lines after releasing the pedal as opposed to being returned to the M/C so your next braking doesn't have to refill the whole brake line with fluid again (possibly requiring pumping the brakes).
3) The overheating rear brake could be a separate issue. You could have a bad/partially blocked rear brake line. Yes, the rears are serviced by the same metal brake line but it T's off at the differential to each side. The right rear is the furthest away from the M/C so even a small blockage there could affect the release of fluid back to the M/C. The right rear is the last leg the fluid travels, furthest from the M/C.
4) Finally I would just bleed the whole system again, including the M/C. Air in the M/C can also cause the problem you report with no pedal. To bleed the M/C while on the car connect one end of a clear plastic tube that fits snugly over the fitting on the lower bleeder valve of the hydrovac unit and insert the other end into the brake filler reservoir on the firewall, making sure end of the tube extends below the top of the fluid throughout the process. Pump the brakes slowly while watching the tube for air bubbles. If bubbles, keep pumping until there are no more. Then bleed the HydroVac as detailed in #2 above then the rest of the car starting at the right rear.

Good Luck
Terry

[Warren Rauch #4286]

 Before I would start worrying about major leaks or hydrovacs, check the return spring on the bad wheel. If the shoes aren't returning ,the shoes will drag and the wheel will be hot. The extra fluid in the fully extended cylinder,could short the master of fluid. If the master was down a little, it might run short and pump air. Air in the system would be more noticeable at higher speeds ,that in stop go.

Warren

[tcom2027]

That really is an odd problem. Pedal to the floor would indicate a leak. Has your fluid level dropped?
Then the rear wheel getting hot because of the shoes binding is another odd one, initially I thought a faulty brake hose but there's only one hose to the back axle so that would affect both rear wheels.
For no obvious reason the power brake unit keeps coming to my mind🤔.
I think I would first check if it's losing fluid.
If it is then find the source of the leak (it could be in the power brake unit).
If it isn't I would jack the car off the ground and take all the hubs off and check everything is moving freely including the parking brake mechanism (if that's sticking on one side that would be the rear wheel problem).
Then redo the major brake adjustment procedure as per the manual.


Good luck.
Phil

Yep Phil, I'd opt for a seized right side brake cable and start troubleshooting there.  The e brake, its operation and adjustment is one of the most ignored components on many cars. Master cylinder and booster problems would likely manifest themselves in a single axle or both axles' brakes.

With a seized shoe the heat generated would heat the drum, expanding it and it would also boil the hydraulic fluid in the cylinder leading to a spongy or low pedal. You didn't say if the brakes pumped up. It's a problem race cars have which is why they run super high grade high temperature fluid. Even with the special fluid they have problems with low and  soft pedal from time to time. 

Other possibilities are broken return springs in the RR or an outside chance the e brake lever or automatic adjuster (assuming your car has them IDK if that is so.)got snaggled up inside the drum although that is doubtful.

Hope this helps.

tony

 

[tluke]

Before I would start worrying about major leaks or hydrovacs, check the return spring on the bad wheel. If the shoes aren't returning ,the shoes will drag and the wheel will be hot

Warren's suggestion is probably the best. I was thinking last night that you may have replaced the shoes and wheel cylinders without replacing all the other hardware inside the drum. I never do a brake job on a really old car without replacing the return springs and other parts holding the shoes in place. A bad return spring is not necessarily broken but simply weak. It might retract the shoes enough to relieve the braking pressure but not enough to eliminate all the friction. That could definitely cause the hot drum as could to Tony's e-brake problem.

Even if the hot right rear wheel is the cause of your no pedal issue that "returned to normal" after tapping the pedal (pumping?), you still want to bleed the brakes including M/C as suggested after resolving that issue. The no pedal issue seems to point to air inside the lines somewhere, whether fluid was boiled out by the heat, caused by improper bleeding of the power brake booster or a leak somewhere.

[Michael Petti]

Just a thought. Check your backing plates and be sure the points that the shoes slide on have not worn over the years. A ridge can develop over the years preventing the shoes from retracting. The extended shoes will heat your drum, and cause the low pedal since the fluid was not pushed back into the master cylinder. Going over a bump  can dislodge the shoe that is just caught on the ridge allowing it to retract. That may be why problem intermittent. This happened to me and fix was to drill a small hole in bashing plate, rub in J.B. Weld, sand smooth and problem was solved.

[Lexi]

Just back from Hearsefest in which we caravaned with several vintage hearses. The 1954 Pontiac hearse developed the same issue after a hard brake application. Still could drive the car around, but brake pedal almost at floor to stop after that. A number of us discussed this issue, which has yet to be resolved, but we were thinking a master cylinder problem. Will report back should I learn of the outcome. Clay/Lexi

[Julien Abrahams]

Thanjk you all for the suggestions. THe '54 has to wait because I am first working on a friend's '66 Eldorado. Once that is done, I can make room for the '54 (beofre or after my '51 Buick will get a rebuild of the fuel pump.
Later I was also thinking return springs. Not sure where I can get a set? It probably will not cost the world, so might be worth trying. Also good suggestion for the e-brake. I did not check that. Only wondering a bit how to check that. My plan of attack is now to first double check the fluid (which I topped off last time, so it should be fine) both. A couple of months back I had the same issue. I cleaned the shoes, bled the whole system (including the master and booster section) and it was fine for a while, so I figured I fixed it. Apparantly not....

[Jeff Rosansky CLC #28373]

For what it's worth, I went to my local Carquest. They had guys behind the counter that had been there for years and have actually worked on a car.
I brought in all my old springs and pins. He got out a dog-eared book about the size of a phone book, and matched up all the hardware, and ordered me a set.

[Lexi]

There was, and may still be a vendor on Ebay who was selling vintage Cadillac spring sets. You might want to check there. In these kits there were also other related parts such as the the rubber boot plugs for the brake spoon adjustment cut outs, for example. Have a look on Ebay. Clay/Lexi

[tluke]

allcads.com is closing at the end of the year and has everything 40% off (not affiliated). I was looking at '55 parts to see if there's something I should get and I saw brake hardware sets for $27 for two wheels. I think that was before the 40%.

[tcom2027]

THanks Terry,

I just cruised his eBay site. Here are a few prices.

'53 rear bumper  looks to be rechromed     $1600
'56 bumper ends                                          $635
 Pr  "      "                                                     $1160
'41 Grille                                                      $1405 Good deal,IMO, based on how it
                                                                      looks in the pictures.
 '42 hood lip                                                $365
'49/56 Recored radiator                              $1000
.......and the deal of the month.
1994 Playboy magazines                            $5ea.

THere aren't many '41 parts featured. A lot of beautifully replated '48 thru the late fifties parts.  Lots of eye candy.

I bought a '41 hubcap removal tool. $15 shipping to NorCal.  Oh well.  The listed price of the tool is $15 and that is
 what the price was at check out plus shipping.

I had a chance to meet Ed and see his warehouse in the early eighties. PArts were stacked on shelves in long rows, all tagged and inventoried. It was amazing. THe back lot was filled with cars in all states of disassembly, along with a few made cars.

I was a newbie restoring a '41 coupe and had made the trip to Sylmar from Santa Rosa Ca. to see his inventory. He had most of what I needed the first time I was there. I needed a neutral safety switch. He had a couple of boxes of them. Same for the letters on the shift quadrant. THis was before they were repro'd. I think a I also got the chrome strips for the inside door panels. All pristine. ANd the chrome  chrome fender spears along the rear fenders, equally pristine which George MacVey had repro'd and had a hell of a time getting good ones, but ultimately he did.

I figured the parts would be expensive and wasn't disappointed. But..... he had them. This was in the days of Hemmings, phone calls and letters. 

He looks good in the picture. Rock on, Ed, rock on.   

tony
                                                 

[Lexi]

allcads.com is closing at the end of the year and has everything 40% off (not affiliated). I was looking at '55 parts to see if there's something I should get and I saw brake hardware sets for $27 for two wheels. I think that was before the 40%.

I did see brake spring kits in the 50s Cadillac section. Did not see the rubber plugs, but otherwise looked complete. You would have to specify your year to see if in stock for sure. Clay/Lexi

[Julien Abrahams]

Update:

First I checked the brake fluid. This was still about 3/4 inch from the top(where I last filled it upto and where it according to the SM should be).
Removed both rear wheels and drums. Checked the springs and free movement of the e-brake mechanism. This was all moving freely. In the meantime discovered that the left rear wheel locks up first when applying the handbrake. So I assume that the rear right brake can be adjusted a bit tighter. But i did not measure with the feeler gauge. Will check that next weekend.
With the springs nothing seemed amiss. I removed the left and right wheel return springs to discover that the two springs (one side) do not have exactly the same shape. (See picture). One has a much sharper hook on one end than the other type. But on the left wheel there were two springs of sort of speak shape A and on the right wheel there were two springs of shape B.
I assume that each wheel "needs" one spring of each type.  The shop manual does not give any information on that. I installed the springs the way I thought it need to be and please correct me if I have done it wrong: the slightly shorter spring with the hook that has a smaller angle to the primary brake shoe. The slightly longer spring with the larger angle hook on the secondary brake shoe.
If somebody can confirm that this is correct or wrong, please let me know.
I believe that this might be the cause of the problem. Springs not being installed correctly causing the shoes to not properly retract and cause the brakes to drag.
Just to be sure I re-bled the whole system (including the brake booster) in the order that was suggested.
On a test drive the brakes felt good and they don't seem to drag. Albeit it was a short test drive.

[Warren Rauch #4286]

       master parts book (1960) group 4.3800 spring

 part # 497834 is used on front and rear ,primary to anchor and secondary to anchor.
               8 to a car  4 7/8" long.
                Just how do you measure? Not explained.
 Warren

[dn010]

"Raybestos H1456K Professional Grade Brake Backing Plate Plugs" (Amazon) are less than $6 for 4 and should work fine as replacement plugs.

I did see brake spring kits in the 50s Cadillac section. Did not see the rubber plugs, but otherwise looked complete. You would have to specify your year to see if in stock for sure. Clay/Lexi

[Julien Abrahams]

master parts book (1960) group 4.3800 spring

 part # 497834 is used on front and rear ,primary to anchor and secondary to anchor.
               8 to a car  4 7/8" long.
                Just how do you measure? Not explained.
 Warren

Well, I did not measure with a caliper, just put them side by side (as shown in the picture). And there were two pairs. Also the shape of the hook is different (as can be seen in the photo). Perhapse different springs have been installed somewhere in the last 70 years?