Got an update. Checked the brake adjustments. Wow. How did they get so loose? The fronts were so loose that I could take a screwdriver and move the star wheel back and forth about a half an inch. Took a long time to adjust the front brakes up. Checked the rears and they were pretty tight. Now the old girl has a firm pedal every time and she stops every time. However, if I hold my foot on the brake pedal it will start pushing back at me. I tried once today to see how much it would "grow" if I kept constant pressure on it. Came up all the way and held the brakes on even after I took my foot off the brake pedal. Three or five seconds later the brakes released. So I guess part of the problem is solved, now I am going to have to look at the booster for vacumm problems. Or maybe the check valve?

 

The MC does have a check valve in it that could be causing this. I drove mine a bit and the pedal goes down quite a ways now. I can pump twice and make up the "slack"

I probably need to adjust front and back. All was new to start with. I have the engine and trans out now so I am not messing with the brakes yet. I rebuilt my MC but I still think the check valve inside is defective.

 

If you push on the brakes and hold it, and the then the pedal starts pushing back at you, the booster is bad. Period. Spend the $250 and get a new booster, problem solved.

 

Good to know about the booster. Bad news since it is only a couple of years old, if that. Then I have to do the whole bleeding thing again. I know, whine, whine. That is what it takes to fix it and give me full confidence in my brakes so be it.

 

B3T-2309-B .. P/B Booster Major Repair Kit

 

Thanks for the part number! Is the rebuild that technical or can an average guy do it himself? I'm thinking it isn't much more than a mastercylinder. Anyone rebuilt one and live to tell the tale?

 

56f600-I too,have 3 boosters to rebuild-so---I am watching and waiting on your lead!!!I cannot believe they are that hard to rebuild, but the exploded view of the 56 ford power brake booster for TH. is large and detailed. HOPE I CAN DO IT TOO???BILL

 

I bought my rebuilt booster from Cascade Friction Materials in Tacoma.

They told me that they send them to some place in Portland to get them rebuilt. The price was $125 exchange.


Cheers,



Rick

 

I wouldn't condemn the booster so hastily. I can understand how a firewall mounted booster might fail and kickback the pedal since it has a mechanical link to the pedal. But a frame mount booster is just a wide place in the brake line with piston in it. It has no reservoir it just works with the fluid in the system. A little bit of kickback can happen when the booster initially works when the brakes are applied but then fails. The extra pressure that the booster was making is lost and as some tension is relieved from the brake components a little fluid flows back toward the master cylinder. But in order for the brake pedal to be forced all the way back up while the brakes are still applied, that would require some additional volume of fluid introduced to the system.

This is indeed a mystery. Are the rear brakes running hot enough to cause the brake fluid to boil?

Craig

 

According to a shop repair manual that I have from the period it states that to test the booster depress the brakes to bleed off any vacuum remaining in the lines. Next press the brakes slightly then start you truck. If the brake pedal moves away from your foot or becomes easier to press the booster is working. If the pedal kicks back then you have a vacuum leak. That could be from a busted diaphram or a leaking hose. I would check all vacuum connections for leaks, If that turns up nothing then I would have to agree with 2speed and say that the booster is at fault. This procedure is for all type boosters be it remote or firewall mounted. What is actually helping you stop is atmospheric pressure not vacuum. The fluid from the master cylinder does not move the slave cylinder the diagphram does so if the system cannot produce a vacuum the atmospheric pressure cannot move the diagram and the brakes work as if they are standard manual brakes, The brakes still work because the fluid is still able to pass through the slave cylender thus bypassing the booster all togeather.

 

Is there any brake fluid in the booster chamber?I thought booster was just a air vacuum chamber.Mine has some fluid in it.bILL

 

that is a big negotory there good buddy.

 

OH-CRAP!!!Thanks-good buddy!I will be needing some rebuild kits.Bill

 

So I should when I get home tonight pump the brakes without the engine running to clear any residual vacumm. Then while holding my foot on the pedal start the truck. Pedal down=good. Pedal up=bad. I hope it isn't the booster. I willalso check hoses for vacumm leaks. I'll let every one know what I find. Thanks.

 

that is correct good luck!!!