58 Power Brakes

[zavorotp]

If the power brake system is not working, will the brakes still work? I have a situation where I have solid pedal after replacing all lines, etc, but the brakes do not work. The rear of the car is on jack stands and the wheels continue to spin when in gear even when I stand on the pedal. My first thought is the master cylinder, but I don't want to start tearing into things before I have an idea where to look. Thanks

[jopizz]

The brakes should still work. When you replaced the lines did you bleed them good. I usually have to do it a number of times after replacing lines. How old are the rest of the components, e.g., the wheel cylinders and master cylinder. If they haven't been replaced and the car has been sitting for a long period of time they will need to be replaced also.

John

[tbird430]

In short, yes. You should still have "manual" brakes to stop the car.

Did you replace all the rubber flex hoses on your '58? Seems like there are 5 up front and one in the rear (above the rear axle carrier)...

-Jon in TX.

[Dakota Boy]

Rotten rubber hoses?

Seized wheel cylinders?

I like using a Mity-Vac for pulling air out of the system.

Without the power-assist, you just have to press the pedal harder. According to the Ford Shop Manual, the difference in master cylinder bores I believe was only 1/8" on the manual brake m/c vs. the power brake m/c.

[simplyconnected]

Originally Posted by zavorotp

...I have solid pedal after replacing all lines, etc, but the brakes do not work...

That is the classic symptom of a bad booster. 1958 Squarebirds used a bellows-type (hydrovac) booster just to the right of the brake pedal.

Hydrovac boosters go bad over the years. I know of 'rebuild shops' that change parts, but I suggest you use a firewall-mounted booster. They are cheaper and more available. The challenge is to find a bracket and setup from a 1960 Squarebird. - Dave

Test Power Brake Booster

If the pedal feels "hard" while the engine is running, the booster isn't operating correctly. If you suspect the booster is defective, do not attempt to disassemble or repair the power booster. Doing so is unsafe and will void your warranty.
Test 1

1. With the engine off, pump the brake pedal to remove any residual vacuum in the booster.
2. Hold pressure on the pedal while you start the engine. When the engine starts, the pedal should drop about a 1/4", this indicates that the booster is working properly.

Test 2

1. Run the engine a couple of minutes.
2. Turn the engine off and press the pedal several times slowly. The first pump should be fairly low. The second and third should become slightly firmer. This indicates an airtight booster.

Test 3

1. Start the engine and press the brake pedal, then stop the engine with the pedal still pressed. If the pedal does not drop after holding the pressure on the pedal for 30 seconds, the booster is airtight.

Inspect the Check Valve

1. Disconnect the vacuum hose where it connects to the intake manifold. Do not disconnect the vacuum line from the booster. Air should not flow when pressure is applied, but should flow when suction is applied. If air flows in both directions or there is no air flow, the valve needs to be replaced.

Verify Enough Vacuum

1. Check the operating vacuum pressure when the engine is at normal operating temperature. There should be a minimum of 18 in. of vacuum. Vacuum may be increased by properly tuning the engine, checking for vacuum leaks and blockages in vacuum lines.

SOURCE- CPP BRAKES


There is also a diagnostic sequence found in the Shop Manual.

[zavorotp]

Thanks, folks. I'll be going through the whole system again to be sure there is no air in the lines and test the power assist to be sure all is well. Again, thanks for all the input.

[dennis]

I have non power brakes. With that said I had the same problem. The car would not stop without really standing on the brakes. I checked every thing, again. New everything. Well stupid me, I did not have the brakes adjusted enough and oh, when I checked the brake fluid in the M/C it was empty. I adjusted the brake until I felt a little drag and then backed it off just a little and I filled the M/C with brake fluid. The car stops just fine now. That's my story and I'm sticking to it.

Just might want to check it out