1959 Fleetwood brake problem

[mo1959]

We are restoring a 1959 Fleetwood.

Problem we are having is with the power brake booster and the master cylinder.

We are unable to build brake fluid pressure to the system.

We have the master cylinder bolted directly to the power booster.

Should there be another spacer or rod between the master cylinder and the brake booster, to give it a longer stroke to help produce more pressure and do we need some kind of seal between the booster and cylinder.

We do not have any other parts for this.  If we do need parts does anyone know where we can find them.

[Ken Perry]

There are spacers on some but not all 59/60 Cads. There should be a seal on the back of the master in a grove. Did you bench bleed the master first? That matters. Always bleed the farthest wheel from master first. Hope this helps. Ken Perry

[mo1959]

Thanks

Yes we bench bleed the master and we are able to bleed the system, but pedal bottoms out and no real pressure to the brakes.

We think that we are not getting enough movement on the master to get the pressure we need.

[Ken Perry]

Over the years I have got master / boosters that were bad,when they came back from the rebuilder. Also got a new master that was bad,becouse the bleed back hole was drilled in the wronge place. I only run (NEW) master cylanders,never rebuilt. Also brake hoses swell closed on the inside,rust on the inside of the steel brake lines,kinked or smashed lines,wronge size rear wheel cylanders, drums turned down to far ,so not enough travel,brakes way out of adjustment.The problem lies in one or more of these issues. For such a simple system they can give you grief. And we are talking stoke master / booster are'nt we ?  Ken Perry   

[n2caddies]

On my cars when I start restoring them I first replace all the wheel cylinders with new, new hoses , inspect the steel lines for bends or leaks flush fresh fluid through them, new master cylinder and if there is no pedal pressure, rebuild the booster. I would not trust the unknown service history of a 50+ year old car I plan on driving.
Randy

[mo1959]

Thanks to both of you.

We have replaced the entire system with all NEW parts and lines from front to back. the only thing that is rebuilt is the Booster.

We think we are Not getting a full stroke on the master cylinder. 

Does anyone know where we can get a correct spacer?

[Blade]

Ken & Randy,

So you guys saying go for aftermarket instead of rebuilt? I am planning to convert my convertible to a dual system using a 67/68 master cylinder and booster.    Thanks!

[76eldo]

I have a 1960 booster and master bolted together that came out of a running car.
I dont know it it's the same as 59 but I would be willing to sell it.

Brian

[R S Steven]

When I rebuilt my brakes I had to adjust the brakes in order to get any pressure on the pedal.  If the shoes aren't adjusted correctly, the master will go to the floor without ant pressure being built up.

[Blade]

Brian:

Yes I am almost 100% certain they're the same - if anyone knows otherwise please let us know.

R S Steven:

Good point addressed!

[Ken Perry]

59/60 are the same. And yes the brakes have to be adjusted or there will not be enough throw. Ken Perry

[mo1959]

the car has the Delco booster on it, just like it had from new.

Someone had taken the master off and could not find a correct replacement.

He said that he thought there were some other parts to the assembly but was not sure.

Thanks to all of you for your help.

[SixDucks]

Hello all,

I had the exact symptoms as you describe with the braking system on my '62 Fleetwood. I replaced ALL of the components with the exception of the power booster. I have a friend that told me to verify if the push rod was adjustable. As it turned out I needed to adjust the length of the rod to achieve pressure in the lines.
I'm uncertain if your system is similar to mine, but if so perhaps this will resolve the issue.
Hope this helps.
Terry

[m-mman]

On boosters that have adjustable push rods you adjust them to provide the correct pedal height but not such that the rod is too long.

You ensure that the booster push rod is short enough by looking into the master cylinder reservoir as the pedal is depressed.  if you see a small bubble(s) or 'gush' coming from the bigger hole in the bottom of the master cylinder (there are two holes) then the system is creating new pressure with each push BUT more importantly it is completely releasing the brake line pressure when you have removed your foot.

If the pressure is not vented each time, the brakes hang up a little bit each time you push the pedal and eventually they are completely locked until you are forced to wait for the pressure to seep down.

Changing a master cylinder can make this adjustment necessary as it depends on the depth of the hole in the back of the piston in the master cylinder. It is always possible that the hole is a little deeper in the replacement master.

Years ago I did a complete brake job and had a firm pedal about 1/16" off the floor. Could not figure it out! turns out included in the box with the new master was a small little rubber plug that was supposed to be inserted in the piston for my application. I pulled the master, inserted the bit of rubber and 'poof' a perfect pedal. A master cylinder with multiple applications. Who woudda thought?? 

Note: all the above is based on a system that has been properly bleed and the shoes are properly adjusted. 

[mo1959]

Thanks for all of your help.

We are looking for a rubber spacer.

[mo1959]

rubber spacer does not work.

[m-mman]

Tell us more. . . .

There is a deep hole in the piston in the master cylinder that the push rod from the power booster sticks into(?)

The push rod from the booster DOES extend and retract as the pedal is pushed(?)
I will assume the pedal linkage swings freely and the booster moves easily. The brakes on my 1959 Lincoln conv were horrible. the pedal was low and would not return. Someone added a return spring under the dash. Couldn't figure it out. Eventually I pulled the entire under dash linkage out (no easy task) cleaned polished and lubed ALL the pivot points (there are 4 of them) and poof everything is fine.

You put a rubber spacer into the hole in the piston in the master cylinder(?)

This rubber spacer must have(?) taken up some of the space between the push rod and the piston . . . ?

The space/slack that was taken up must have forced/allowed the push rod to go further back into the booster and there fore pushed the pedal higher . . . ?

Tell us more about what is happening.
Tell us more where our assumptions are not consistent with what you are seeing.