brake queston....

[Ghost]

I have two lightnings, a 93 and a 94. My question is on my 93 the brake pedal is VERY firm and if you keep applying pressure to it the pedal never sinks but on my 94 the pedal is kind of soft and if you keep applying pressure to it the pedal eventually sinks to the floor. At first i thought the 93 was correct in how firm it was so to correct the "softness" in the 94 I replaced the master cylinder but that changed nothing. Now I think the problem on the 94 is that maybe the brakes vacume booster is going bad and that's what's causing my pedal to sink. So now i just need to know which one is correct, the 93's "very firm pedal", or, the 94's "kind of soft" pedal. Any ideas ? How does the pedal feel on your trucks? Thanks

 

[MO351]

My 94 has a firm brake pedal. I've never experienced that "sinking" problem with my L. Mine will stop on a dime if they don't lock up in front. I've got a little bit of a grinding feel in the pedal and can kinda hear it from the left front brakes but I've still got pad on there and there are no grooves in the rotor at all. Who knows.

 

[Abby Normal]

Where Y'at Ghost, Check the flex hoses to the front calipers & to the axle. If there are any cracks in the outer covering replace them.
So whats been done to the '66FB. I got a '66 FB & race a '65 Coupe. Do you race at HRP? I may have to keep an eye out for ya.

 

[core-rider]

It sounds like you either have air in the lines that needs to be blead out or there is a leak. If you haven't already done it, bleed the entire brake system. If you've done that then check the system for leaks. A good place to look would be the brake cylinders on the rear drums. The seals can go out in them and cause your type of problem, but not be in plain sight because they're hidden behind the drums.

Also check the brake lines and hoses for leaks. Your pedal should be firm once you press it down and shouldn't bleed off. Good luck with finding the problem.

 

[9T4 SVT]

On the 94 there is an electronic switch on the top of the Master Cylinder (has wires connected). This switch can cause the problems you have described. Do a visual of the switch, if you see any seepage (fluid) replace it. Your local Ford dealer should have it for about 20 bucks.
The 93, I'm not sure if it has the same switch. Sounds like the 93 is ok.
My 94 didn't give me any warning. Went to stop one day and the pedal went to floor (pucker factor about a 100), pumped real fast and got it stopped. replaced he switch and all is well.... Hope this helps..

 

[Ghost]

If i had a leak then fluid would be missing from the master cylinder and it stays full. Maybe its the sensor, I'll have to check. I'm pretty sure that I bled the system correctly, I even bled the ABS thing under the cab. So am i correct in assuming that all of your peddals out there are VERY FIRM, as in no play or squish when your foot first starts applying pressure ?

 

[Ghost]

Hey Abby, I do race at HRP in the points, last year I was lucky enough to finish 5th overall in no electronics. My car has an 87 302 roller block bored 30,TRW forged pistons,ford e7te heads cnc ported by Power Heads, ford motorsport x-303 roller cam, performer RPM intake, holley 750 double pumper, 3300 stall, c-4 with B&M shift kit, 9 inch rear with 3.89 gears. It's white with light gray racing stripes with a shelby front racing apron and cowl induction hood. This weekend I am planning on starting my cam swap, I have a custom grind from Bennet Racing that needs to go in and after that I'll be working on a gear swap to 4.33's to get the rpm's up a little more because right now I'm crossing at 5500 rpm and it needs to be around 6500.

 

[Chris Wilson]

A very firm pedal can be a sign of a power brake booster going bad as well. I have driven vehicles where the booster was bad and it almost felt as though the vehicle was trying to push the pedal back up at you. I would try replacing the sensor as mentioned before. Probably your cheapest fix and easiest thing to eliminate outside of checking for leaks and bleeding the system. One of you guys mentioned having a metal feel in the pedal despite having plenty of pad left. I've had this with certain brands of pads before. It has to do with them being semi metallic and the metallic content of the pad. It drives me nuts to drive a vehicle like that. Some rotors and pads just don't mix in that respect. They offer lifetime warranties on pads these days despite the fact that they are wear out items. The metallic content is very high so they don't wear out. This takes a toll on your rotors and you end up warping them. Breaking has to do with dissipation of heat and your pads are designed to wear. Just my experience. I haven't tried any of the newer ceramic pads that are supposed to be quiet and have lower dust. If any of you have any experience with these I'd love to hear it.

chris

 

[MO351]

That would be me, Chris. I figured it was because of the metallic brake pads. Yeah it drives me nuts because it feels/sounds like it grooving my rotors. Drives me up the wall. I, too, would like to know some good pad recommendations. I think I'll make a new post.

 

[Daniniowa]

I replaced the vaccuum booster on my '93. It went bad. It had a really firm feel, then got softer as you pushed the pedal down. The booster wouldn't work for the first 1" of travel, then it would work. The FORD dealer confirmed the bad booster when I went to the dealer to have them change my fuel filter. I'd try bleeding the brake lines first, as that is the cheapest. The booster is pretty cheap also, but mine came unfinished from a parts store, so I had to paint it.