Hey guys. Has anyone in this forum performed the crown vic swap and have any braking issues? The current situation, as I drive the truck the brakes gradually start building pressure. I purchased a dual master cylinder from LMC for non-power discs. All new hard and soft lines to each caliper (front and back, swapped the limited slip 8.8 as well). Running DOT 3/4 fluid. I even pulled my brake pedal pin and adjusted the length. As I installed the new current master, I did have to apply pressure to get the cam bolt installed. I pulled the pin and cut .5" off. Reinstalled, brake pedal hit the floor and required 6 pumps to get any pressure. Pulled the pin again and add .25" back on the pin. This seemed to work out, I thought. The problem returned. Debating pulling the pin again and cut .125" off. Any other suggestions? I've bled the master and brake lines multiple times.

I also posted this in the Fabricator forum as well.

 

When you say "pulled the brake pedal pin" are you referring to the push rod, from pedal to inside the master cylinder ?? On ANY master cylinder push rod, there needs to be 1/16"to 1/8" free movement of the push rod before solid contact with piston in the master cylinder. This ensures the piston can come all the way back to the retracted position, so all fluid applied when stepping on the brakes can go back into the master cylinder reservoir. If that fluid can't return, the brakes will be partially applied when you release the pedal and each subsequent time you step on pedal, you will add more pressure and apply brakes harder. With all adjusted properly, just pressing the pedal with your hand you should feel a little movement of pedal with NO resistance, then feel an effort as the push rod contacts the Master Cylinder Piston.

 

You might look for an adjustable push rod instead of the cutting and adding you are speaking of

 

I need to ADD...... I don't think our 66 slicks have a brake pedal return spring and the weight of the pedal rests the push rod against the Master Cylinder Piston. So you shoud pull back up on the pedal to detect the play/free travel you are looking for.

 

Another question,

I'm not seeing anywhere where you have bleed the brakes. Maybe you missed saying that part, but unless all of the air is out of the system, it will act similar to what you are saying.

 

Thanks for all the comments. I have bled the brakes. Often. And yes I'm referring to the push rod. I've concluded that I will grind off .125" off the length of the push rod. Then use the camber adjustment in the connecting bolt to take up any slack from there on.

 

OK on your last post, hope it resolves the problem. Another question(s) as I am not up on all about Crown Vics. The 8.8 you mention, is that out of the Crown Vic (C V)? So you have discs on all 4 corners? You added spring perches and into the 66"s rear springs? Did the non power MC from LMC, have the same bores as the CV's MC, so you are moving the same amount of brake fluid to the calipers as the CV MC did.

 

The 8.8 is out of the Crown Vic. And yep, I have disc on all four corners. I flipped the axle, so the axle sits on top of the leaf springs with new welded on perches. I believe both master cylinders (CV and LMC) are 1 inch bore.

 

Thanks, hope to hear of you resolve.