I went back a ways in the posts and didn't see anything that might refer to my problem. If I overlooked a post I appologize. I have 2000 Super Duty V-10, Auto, 4wd, crew cab with aproximately 180,000 miles. Ever since I bought it, about six years ago the brakes have been less than stellar. I have replaced the pads, rotors and the rear calipers. I have bled the system and replaced the brake fluid in the rig. I still have to pump the brakes a couple of times to get good stopping power. I pull a 7000 lb, 24' travel traler with this truck. If anyone else has had a similer problem and found the cure for it I would appreciate any thoughts or advise on it. I think the only thing I haven't replaced is the Master Cylinder. Thanks in advance for any responses.

 

You did not say whether any work was done with the front calipers. I am curious if you get a higher brake pedal or actually better braking when pumping the pedal. It does sound like there may be some air trapped in the brake system and with ABS you may require a scan tool to activate the solenoids in order to get the air out of the ABS unit.

 

Hanky, sorry been away from the computer for a while. Yes I did repace the front pads and also the front rotors. I don't notice the spongey feel that I've noticed in the past with air in the lines. I didn't bleed the fronts so this weekend I'll do that. I have a scan tool that will check the ABS but I'm not sure how to activate the solenoids with it. The truck has four wheel ABS. I can bring the pedal up a bit with a second pump. and they feel solid. Thanks for the reply, it's giving me more to think about.

 

It may not apply here, but it has happened before. That is if the person replacing the calipers is not that experienced they put the replacement calipers on the way they took them off and they were upside down with the bleeder screw on the bottom. Now all the air in the caliper can't be removed. I just thought I would mention it here and as I said it may not apply. Did you remove the caliper pins and clean out the bores before installing the calipers ? A synthetic or other approved grease is required to lube the pins . Any other type grease will cause the rubber pin boots to swell and become ineffective as far as preventing trash from getting in there and causing the pins to bind and jam tight preventing free movement.
If the master cyl has never been replaced consider replacing it. If the cups don't seal well the first brake application allows some fluid to get past the cups and the second pedal application gets more volume/pressure to the calipers.

 

You know it may just apply, I'll look in the morning when I get off and see what the orientation of the bleeder screws are. It seems to me they're on the top and that's where they were when I removed the old ones. At least I hope so. You also mentioned the master cylinder and that was going to be my next thing to change. I do have solid brakes, you just have to pump them twice to get what feels like good braking. I'm sure the financial manager (wife) won't be overly thrilled with more money going into the braking system, but when we have our 7000 lb. trailer behind us, she'll see the worth of it all. Thank you so much for your advise, I'll let you know how it comes out.