Brake and Steering help needed

[Airborne_Sapper]

Gents,

I have a 73 half cab that had drums all around. I got the graveyard power brake set up http://broncograveyard.com/bronco/i-12501-extreme-power-brake-booster-setup-1966-77.html and also installed 77 steering knuckles and disc brake setup. After I installed the entire system and bled it, at the time was building pressure and was feeling fine, I hooked up the booster to the runner on the intake manifold. Once I started the truck I had no pressure what so ever. I mean none. Also while pumping the brake there was fluid leaking from the cap of the master cylinder. So I tried to do the tests that came in the instructions, which were garbage and totally lacking, I removed the hose that runs from the booster to the intake at that time you could build pressure in the pedal. I can not figure out what is causing the pressure to removed by the vacuum in the booster? can any one help with this one. Question 2. The steering linkage from the 73 is not wide enough for the new disc steering knuckles. do you just loosen the sleeve on the linkage and turn out the tie rod end? or would a stock 77 inverted Y linkage be better? or just spend the money on one of the BC bronco heim steering? Thanks for help fellas.

 

[Timmy390]

Just did the Ford Disk conversion and had issues becasue I put the calipers on the wrong side. Yes they will fit left on right and right on left and look correct. Where is the bleeder on the calipers? Is it on top and when I say on top, I mean on top not middle bottom. Even after I was told the bleeders need to be on top, I was still lost till it hit me like a brick. Took 2 days for it all to sink into my thick head...LOL.

The leaking fluid sounds so much like the issue I had. As you pump the brakes the air in the caliper compresses and when released, it shoots the fluid back in the M/C and the cap leaks. What M/C are you using? Did it come with the kit?

As for the steering, yes the disk knuckles require you to extend the tie rods by turning the sleeve. Had to extend mine an inch or more.

Tim

 

[Airborne_Sapper]

I checked and the calipers are installed on the correct side. What is weird is that it only leaks out of the top of the master cylinder when the booster is connected to the intake manifold. Is it possible that there is to much vacuum pressure from the intake manifold causing the valve at the attachment point of the line to booster to fail? Because I do not get any pressure when the vacuum hose is attached but can build pressure when it is not attached, all of this is when the motor is running.

 

[Timmy390]

I'm getting my vacuum from the rear manifold port as well. All I can thing of is maybe the check valve or booster is bad.

So without the vacuum line hooked up you press the peddle and it's stiff but when you hook the vacuum line up the peddle goes to the floor? Do you have to pump the peddle to get a stiff peddle?

Tim

 

[Airborne_Sapper]

I'm getting my vacuum from the rear manifold port as well. I am getting my vacuum front the front runner. I dont think that there would be a difference between the two they should have the same amount or is this wrong? All I can thing of is maybe the check valve or booster is bad. I did the test that came with the booster the results were that the booster was airtight. What test did you us for your booster and valve? maybe the one I used didn't show the malfunctioning pieces.

So without the vacuum line hooked up you press the peddle and it's stiff but when you hook the vacuum line up the peddle goes to the floor? Yes that is correct. Do you have to pump the peddle to get a stiff peddle?
Yes I have to pump the brakes to get a stiff pedal when the vacuum line is not attached. It only takes about 2 pumps and it starts to accumulate resistance. When I have the vacuum hose hooked up the pedal drops to the fire wall almost by itself and it does not start get any pressure even after pumping the brake for a while.

 

[Airborne_Sapper]

Alright well now I have moved the vacuum hose to the back runner on the intake. There was not difference. I also made sure that the booster itself was airtight and it was.Also checked the valve and it was good. Then I checked that there was fluid coming out of the master cylinder when the engine was not running. It was coming out of the both ports. then I tried it again with the engine running and the fluid was coming out at a much higher volume and pressure. Which I am sure is what is suppose to happen but there was still no pressure on the pedal. So I am lost now.

Could there be an issue with the rear lines that I did not change? I figure the hard lines are fine but maybe the flexible rubber line that in on the rear that goes from the frame to the rear axle could be a point of failure. But Would that cause the change in pedal pressure for the whole system? And would the cause be the additional pressure from the booster?

 

[shamu]

Can you send pics of your caliper set up? My email is c-allen9@att.net Timmy390 and I have the exact set up as you and he fought and fought and finally got it right. Timmy390 is on the correct page.

 

[TAC71]

did you bench bleed the master first...before installing?

 

[Timmy390]

Can you send pics of your caliper set up? My email is c-allen9@att.net Timmy390 and I have the exact set up as you and he fought and fought and finally got it right. Timmy390 is on the correct page.

I went 10 rounds with it that's for sure. Been doing brakes for a lot of years and this is the first time I got my hat handed to me. The minute you think you know what you're doing, you're wrong............

If you have to pump the peddle to get pressure, it's air in the system or a bad M/C. I used two 32oz bottles of brake fluid to get my system soreted out.

Your problem is so close to what I had it's not funny. Where do your brake lines attach to the calipers? On top or bottom? It should be on top.

After getting my calipers on correctly, I bench bled the M/C then hooked up the lines and bleed the front pass side first then Driver side. I put a hose on the bleeder and run said hose into a glass jar 1/4 full of fluid. I can then bleed teh brakes by pumping the peddle and watch the bubbles in the jar.

Tim

 

[Airborne_Sapper]

Well my hose attaches at the bottom. I am guess that this is wrong. but I have a 77 and it has the same setup on it and there is no problems with it. As you are looking at the wheel well with the tire off the brake caliper is at the 10-12, on the passenger side, with the bleeder screw on the top and the hose attached at the bottom. I will try to get some pictures posted tomorrow. If they are upside down and to high you are right I have no idea what is going on.

 

[shamu]

1976 f 150 disc passenger side pic.

 

[Timmy390]

Well my hose attaches at the bottom. I am guess that this is wrong. but I have a 77 and it has the same setup on it and there is no problems with it. As you are looking at the wheel well with the tire off the brake caliper is at the 10-12, on the passenger side, with the bleeder screw on the top and the hose attached at the bottom. I will try to get some pictures posted tomorrow. If they are upside down and to high you are right I have no idea what is going on.

The 77 and the 79 ( I have the 79) calipers are the same part number and trust me, the hoses attach at the top.

I had to prove it to myself so with the hoses on bottom and the system fully bleed, I jacked the rear up and let the air out of the front tires which changes the angle of the bleeder basicly putting them higher and bleed the brakes again......guess what, more air came out of the front calipers......Proving I had them on upside down. Everyone was telling me but I couldn't see the forest for all those trees in the way.....LOL

I understand it's crazy they will fit either way but the 77 is worong too. I'm guessing those calipers were gravity bleed before they were mounted.

Here's my thread on it. I evern with as far as buying a new M/C because it just couodn't be the calipers on upside down.
http://classicbroncos.com/forums/showthread.php?t=211263

Ran out and took a couple of crapy pics.......

Driver side standing in front of tire looking down

Driver side behind tire

Tim

 

[Airborne_Sapper]

Here is a picture of my calipers. I was told that they are installed correctly. What is the consensus? The pictures are of the driverside.

 

[Timmy390]

Check out my pic's. My calipers are opposite yours.

They're upside down.....
Just like mine were when I couldn't get them bleed. I had a hard time getting my head around the fact the bleeer needed to be on top not bottom. It's on the bottom right now which you would think is the top because it's above the hose. When you swap them, the bleeded will be on TOP TOP and the hoses will mount on top. With the hose on top it will not contact the radius arm like they are now (if their not their real close) it wil be high in the air and have more room to extend and move. I thought my lines were a tad short till I swapped the calipers.

See how the bleeder is below the pistion cup area on the calier? The upper piston cup area/chamber inside the caliper is filled with air. That's why you get pressure when you pump it. The pumping compresses the air.

To test it, let the air out of the front tires and jack the back up high. Then bleed the front brakes.....you will get air out but not all of it. I did this to prove to myself the calipers were wrong before I swapped them.

I swapped them, bleed them and now have GREAT brakes........

Tim

 

[scrapman1971]

Airborn's is on the wrong side

 

[scrapman1971]

Air bubbles rise therefor the bleeder needs to be at the top. You dont have to change them. U can always take them off, put a piece of wood where the rotor goes and turn the caliper so the bleeder is on top and bleed. Then reinstall;D
Kidding.... U need to swap the calipers although the way i described will work

 

[Airborne_Sapper]

I will give it a try. I just do not know how it could be unless the L that is on the caliper is for the left side of the truck as you look at the front, passenger side, instead of as you are driving it. If so then The caliper holder is on the wrong side as well. Damn it also means that my 77 Bronco brakes are on the wrong side as well and what is really weird is that work as good as my 2010 F150 brakes.

Well After taking a little more time to think about it I see were the air bubble could be and this issue seems to be an easy fix. Could this mistake really be the answer to the complete lost of pressure only when vacuum is applied to the booster?

 

[Timmy390]

Could this mistake really be the answer to the complete lost of pressure only when vacuum is applied to the booster?

It was for me....without the booster hooked up I could only get pressure by pumping the brakes and once the booster was hooked up, it went to the floor. Once I swapped the calipers and re-bleed, it was all good. That caliper is more than half full of air as it sits.

Quick and easy way to see if the caliper is full of air......
Take the caliper off and with it in your hand, holding the bleeder up in the air, crack the bleeder open and have someone press the brake peddle. If air comes out, then you know it's on worng. You could also bleed them this way and not swap them.

No matter what you do or how you do it, the brakes will not work till you get the trapped air out of the calipers and the only way to do that is get the bleeders higher or on top.

Tim

 

[shamu]

I will give it a try. I just do not know how it could be unless the L that is on the caliper is for the left side of the truck as you look at the front, passenger side, instead of as you are driving it. If so then The caliper holder is on the wrong side as well. Damn it also means that my 77 Bronco brakes are on the wrong side as well and what is really weird is that work as good as my 2010 F150 brakes.

Well After taking a little more time to think about it I see were the air bubble could be and this issue seems to be an easy fix. Could this mistake really be the answer to the complete lost of pressure only when vacuum is applied to the booster?

All R and L notes are anatomical. Driver is left, Pass is right.
This same issue happens more than you will know. Been there done it and brake fluid is expensive. Peace Mahola

 

[Airborne_Sapper]

Tim, Thanks man for the help. I would have never thought of that as the issue since my other bronco has them on that way. That seems to have been the cure for the majority of the problem. I have brakes now. I owe you a 12 pack.

Is it normal for there to be little pressure on the pedal in the first half and then a majority of pressure is in the last half of the depression stroke? There is also very little bounce back to the start position for the pedal after releasing it.