2001 F150 XLT 4x4 Regular cab, longbed, Off-Road package
4.6L 4R70W
4 wheel disc, 4 wheel ABS

Bought the truck from a friend who had owned it 14 years and took great care of it. Have been working through a few issues over the last couple weeks and everything has gone great until now!

The truck blew the rear feed line about a year ago while my friend was at his cabin. As a quick fix, he put a plug in the line at the joint going to the rear feed line, effectively blocking off the rear brake system.

When I bought the truck, the pedal was as stiff as can be, and the brakes worked perfectly, albeit only in the front. The front brake lines had recently been replaced, leaving the rear lines all original. I decided to replace them all with stainless.

After replacing all of the rear lines/hoses, I ended up also replacing the front calipers due to completely stuck bleeders. The rears I was able to save. I started bleeding at the pass. side rear, moving to drivers side rear, to pass side front, to drivers front. I got a fair amount of air out of the rear bleeders, as you'd expect. No air out of the fronts, just nice solid streams of brake fluid. I repeated the process two more times, this time getting no air out of any of the lines. I went through two bottles worth of brake fluid in the process.

Here's the trouble... The pedal is still very spongy! Much less so when the truck is not running. When the truck is running, it's going 3/4 of the way to the floor before the brakes engage, and when they do, it's the rears before the fronts. I can pump the brakes when the truck is off to get a stiffer pedal, and the stiffness holds until I let up, so I'm sure I don't have any leaks. The master cylinder never fell below half full during the entire process, and I cannot get ANY more air out of the lines, just solid streams of brake fluid. What am I missing here? I was thinking maybe ABS Module? I've heard these need to be electronically bled. Any input would be greatly appreciated!

 

Check the replacement calipers and verify they aren't upside down. The bleeders must be at the top when the caliper is mounted. If they're on the bottom, they will never bleed properly.

 

Thanks for the reply. They are right side up with the bleeders at the top. I actually learned this lesson the hard way several years back with a Dodge truck I did some work on. I never knew they were so easy to put on upside down, but they definitely are. Unfortunately, not the case in this situation. Thanks again!

 

have someone feel the hoses while you apply the brakes... Some hoses are known to flex on the diameter (swell) and take up more fluid to fill.

 

I work at a dealership, and I have seen a air-powered bleeding system work wonders. Just a thought.

Chad

 

This is what I'm thinking is going to be my next step.. I very rarely take my trucks into the shop so I'm a bit reluctant to have to bite the bullet, but at the same time I'm nearly to the point of submission with this one..

I read a couple of very similar posts on a few other forums yesterday, and they also ended up taking their vehicles into a shop to have the system power bled, with excellent results.

I wasn't expecting a miracle I guess... It just drives me crazy trying to figure out why manual bleeding has been unsuccessful with this truck when I've never had this type of issue in the past. I wonder what's different this time?

Thanks for the response!

 

I've had my dad over the last couple nights to run the pedal while I laid under the truck turning the bleeders. This was one of the first things I looked for, but all the hoses check out good from what I can see / feel. The front hoses are only a couple years old, and the rears I just installed.

 

Do you have access to an air compressor? If so, you can do your own "power bleed".

Before those fancy air-powered bleeders were invented, I just used a 2' peice of vacuum hose and my air blower. You put the hose over the bleed screw tip so it seals, but the wrench can still get it. Poke a hole in one side of the hose about a foot and a half down, and push the tip of your blower in the hole with the tip towards the open end of the hose.

Make sure the reservoir is full of fluid, loosen the bleed screw, and blow the air. The air rushing out will suck the brake fluid right out of the system... And any air.

Make sure to not drain the reservoir and do all four corners. If you don't have this stuff, then you will be further ahead to just pay a shop $80-100+ to do it.

Good luck!

Chad

 

Interesting. I do have everything I'd need to do it that way, I guess I've just never in the past had to learn a different way of doing it. I'll look into this. Thanks!

 

I used to use the same trick to syphon gas out of tanks of vehicles (way bigger hose though) that needed the tank removed. WAY BETTER than getting a mouthful of fuel.

Chad

 

does the air get trapped in the abs module? I thought that once the system is opened, air can get trapped in the abs dump valves in the system

 

I've also heard this, and I'm still wondering if this may have something to do with my issue. If so, I've read they must be hooked to a scan tool and purged that way. I suppose if I try what Chad mentioned above and still have an issue, then I'll have to assume theirs air in the ABC.

thanks guys!

 

Have you tried power slamming the brakes and activating the ABS?

 

Thats what I use, got it at HF for $18. Works wonders.

 

I have not, is that similar to the process of resetting a proportioning valve on the older trucks?