I'm bringing back my Dad's 1967 F100 240cid truck back to life. It's been sitting outside for 10 years in a dry climate and has not been started for that time.
Motor is not frozen and I expect that the truck will start after I rebuild the carb, replace the starter, solenoid, plugs, battery and gas.
I wanted to make sure that after I started the truck that it was safe to drive.
I attempted to bleed the brakes starting with the bleeder the farthest from the master cylinder. The brake system has no booster and is not a power brake system...very basic and simple. The farthest brake did not bleed even after removing the bleeder. The other 3 did bleed and there is fluid in the master cylinder. It was interesting that as I got closer to the master cylinder the brake bled quicker. I went under the truck and was able to manually move the cable to the back brakes so I think the seized pedal is ahead of that.
Could the brake cylinders be frozen/rusted closed/opened cause the hard pedal? I don't expect the master cylinder as it had fluid.
Or could there be a pedal to front brakes linkage issue?
Any help or advice is appreciated.
Thanks.

 

I'm suspecting the RR wheel cylinder is the culprit. Disconnect the hardline at the RR backing plate to determine if fluid flows.

 

I'll try that next time I'm up North.
Makes a lot of sense when you see the brake assembly (dirt, cob webs, etc.).
Do you think that after I bleed the brakes the pedal will move again?
It's hard as a rock right now.
Thanks.

 

Does your truck have a manual or auto transmission?

 

I would think you would want to replace all the wheel cylinders after sitting that long. Cheap insurance because those seals will leak real fast and you will end up doing the job again.

 

Second that. Might seriously consider changing out the MC too --if you're running the stock conventional style cast iron MC. It's made out of the same cast iron material as the wheel cylinders.
--I run a modern aluminum MC so, it doesn't rust but, the brake fluid still has to be changed regularly.



If there's any pitting/corrosion inside the wheel cylinders, a cast iron MC is likely to look the same.

Sitting for 10 years doesn't do brake systems any good. Even in a "dry" climate, there's still a degree of moisture in the air and the brake system will collectively absorb this moisture over time, it'll settle out in the ferrous brake components and begin to rust them from the inside.

Brake fluid, like any other fluid in a vehicle, will degrade over time. For brake fluid, the life span is about 18-24 months before it needs to be bled out and replaced with new brake fluid. Neglecting to keep the fluid fresh will result in brake component malfunctions and failed brakes.

 

3 speed on the column.
I plan on taking the truck to the brake guys to grind out the little rust I have seen in the inside of the drums and to check the system out anyway.
I suspect that I will have to replace the MC.
Just wanted to solve the hard pedal myself as it bugs me why it could be so hard. Probably the brake cylinders as suggest earlier.
So much more fun to start the truck and move it through the gears.

 

With a M/T, the brake pedal (2455) rides on the shaft that is made as part of the clutch pedal (7519).

 

As long as the MC pistons and all the pistons of the wheel cylinders are free to move, the brake pedal will travel forward a short distance with little effort, when applying the brake pedal.

During this process, the MC is pushing fluid out of the MC and into the brake system to fill the wheel cylinders (and brake calipers if a person has discs), to push the brake shoes (or pads) against the friction surfaces of the drums/discs.

Under normal circumstances, there will be very little system pressure on the brake components or opposing the brake pedal during this 'take up' stage. Once the shoes/pads contact the friction surfaces of the drums/discs, the pistons of the wheel cylinders/calipers can no longer move forward. This is the point when the system starts building pressure and you feel the resistence to the brake pedal moving forward.

If a brake pedal is rock hard as soon as you step on the pedal, it can be an indicator that the MC bore is too large in diameter, a bad booster (if equipped with power brakes) or, a piston or pistons in the brake components are seized, causing the brake pedal to immediately build pressure because there is no intial free movement of the pistons before pressure begins to build.

Since the truck has sat for a long period of time, I would just about bet there's a wheel cylinder piston(s) that are seized, due to saturated brake fluid.

On average, a brake system can absorb as much as 2% of moisture contamination per year. Over a 10 year period, this would be a significant amount of moisture collectively building up in the brake system.

DOT 3, 4 and 5.1 brake fluid is synthetic. (DOT 5 brake fluid is silicone). DOT 3 , 4 and 5.1 brake fluids absorb moisture. Even in a sealed (closed) brake system, moisture will get into it through/around the lid seal on the MC and through the sheathing of the flexible brake line hoses.

The molecules of the brake fluid are too large to leak through the pores in the brake hoses and MC lid seal but, the molecules of the moisture in the air are small enough to eventually penetrate through those pores. This is how the brake fluid becomes saturated with moisture and why the fluid needs changing at regular intervals (18-24 months), to keep the moisture content in check.

 

How did you bleed the 3 corners if the pedal is rock hard?

 

if the pedal has absolutely no movement, then it can't just be a single wheel cylinder. It would move as the other 3 expanded. Either the master is shot, or all 4 wheel cylinders or there corresponding lines and hoses are.

Loosen up the 2 brake lines at the master and see if the pedal can move. If not, start with a master cylinder. Best to replace all rubber lines, master cylinder, and all 4 wheel cylinders now. Take and blow out all the steel lines while you have it apart also.

 

A word of caution about blowing out brake lines or brake components with compressed air.

If you do so, make sure you have a (fresh) inline filter at the hose connection of the blow gun.

If ANY compressor oil inside the air line gets blown into the brake system, it can have bad results if/when that oil comes in contact with the seals of the brake components.

The seals are designed for the brake fluid, which is synthetic and not petroleum-based like the compressor oil. Petroleum-based oils coming in contact with brake component seals will cause the seals to swell and split. --that naturally will lead to a brake component failure.

 

Since the OP's truck has a brake pressure differential (aka prop) valve, doesn't it also have to be bled?

50 some years ago, I had a 1954 Oldsmopile 88 club coupe without power brakes.

One time when I was whizzing down the road, I stepped on the pedal, it was hard as a rock. I had to yank the parking brake handle out, run up on a curb to stop it.

Replacing the master cylinder fixed it.

 

If the OP's truck has the original '67 brake valve, it would just be a pressure differential valve. There are no proportioning valves in an all-drum brake F100 (or in a '68-'72 F250 or F350 with optional front disc brakes).

Proportioning to the rear drums didn't come into use on the discs front/drums rear Ford trucks until 1973. Proportioning was one of THREE combined features integrated into one disc/drum valve assembly.

The other two functions of the '73-up Ford truck integrated (combination) brake valve were; metering (hold-off) to the front brakes and pressure differential sensing between the primary and secondary brake circuits.

The '67 brake system would bleed through the pressure differential valve, simultaneously, as the system was being bled out --so long as the system was completely plumbed up.

IF the pressure differential valve spool is shifted inside the valve body, then it may present some restriction to the fluid bleeding out in whatever circuit the spool is shifted towards. The brake warning light on the dash should indicate if the valve spool is shifted, if the brake warning light circuit is working.

 

Ford referred to all with or without disc brakes as brake pressure differential valves (2B257). Ford never referred to them as proportioning valves.

1973/79 F100/350 & Econoline; 1973/77 F500 examples: