I am having a problem with a low, soft pedal in my 1998 F150 XLT with RABS.
I clamped the passenger side front brake hose and my pedal was high and firm. I went ahead and replaced the caliper with a reman from Autozone using new washers for the banjo bolt and bled normally. I still have the problem and still get a nice firm pedal when I clamp the brake hose. Could the hose be bad? The pedal feels the same whether I clamp near the caliper of near the other end of the hose.

Thanks

 

I dont advise clamping off a brake line, but did you also try it on the other side? Get someone to push the pedal while you hold the line in your hand and see if you feel it expand. They do good bad but air still in the system will do the same thing.

 

I had both front lines clamped and removed the clamps until I felt the soft pedal which pointed me to the passenger side. I used vice grips with pieces of hose over the teeth to be as gentle as I could with the brake hose.

I had my wife pump the pedal with the engine running and felt no expansion in either of the hoses in the front.

 

when was the last time you put fresh fluid in the system??old fluid brakes down the inside of the hoses after awhile. older the fluid the more moisture you probably have in the system. you should flush and refill every few years. bleed all 4 wheels ,go around 2-3 times get as much old fluid out as possible. that might help ya.

 

I flushed the system about 6 months ago. The old fluid was pretty nasty. The fluid is coming out clean and bubble free at all 4 corners. Maybe I just have a stubborn air bubble trapped in the caliper somewhere. I tried tapping on it lightly with a hammer while bleeding to dislodge any air but have had no luck.

Thanks for the suggestions fellas. Keep them coming.

 

It does sound like air trapped in the caliper.

Try removing the caliper from the mount, and open the bleeder screw, and then manually hold the caliper in a lot of different positions, positioning the bleeder screw at the very top.

If you have the master cyllinder cover off, and the bleeder screw open, fluid will flow, and if any air is trapped, by moving the caliper around, and positioning the bleeder screw to the very highest point, it will let the trapped air escape.

Although I have seen this happen with clutch slave cylinders before, and this method worked to remove the trapped air, I have never seen a "trapped air" condition in a front brake caliper before.

EDIT: Make damn sure nobody touches the brake pedal while you have the caliper off....in fact, don't let anyone inside the cab while you do this.