My wife and I just bleeded the brakes on our 2005 F150 FX4. I installed our new Brake Smart electric brake controller (used for towing) and got some air in the lines. Everything seemed to go fine, but the pedal still seems spongy.

I talked to a mechanic friend of mine and he said that you can't bleed modern vehicles equipped with ABS brakes. He said that you have to connect to the trucks computer and have the computer tell the ABS braking system to "open" and let the brake fluid flow through it. He said we might be feeling air trapped in the ABS braking system. The only way to fix it correctly is to take the truck to the dealer.

I just called my dealer and they said they just do the standard RR/LR/RF/LF bleeding order. But they have a book that has the actual proceedure in it and they didn't have time to look at it. So I'm worried the dealer won't even do this correctly.

Anyone know about this? I wish I could remember how the brakes felt before I installed the brake controller. But my wife drives the truck and she can't remember.
--
Mitch
'05 FX4

 

Carquest has some pdf files on this topic. Trucks with the 2 pistons on the front brakes are a real pain in the butt:

http://www.carquest.com/BRK_tech.htm

 

Here's something from TheDieselStop.Com forums:

Under the ABS section of the service manual, on bleeding the ABS system, they refer you to the "Brake Bleeding - System" section, which I have posted below:


1.Clean all dirt from and remove the brake master cylinder filler cap and fill the brake master cylinder reservoir with the specified brake fluid.

2.Place a box end wrench on the RH rear bleeder screw. Attach a rubber drain tube to the RH rear bleeder screw and submerge the free end of the tube in a container partially filled with clean brake fluid.

3.Have an assistant pump the brake pedal and then hold firm pressure on the brake pedal.

4.Loosen the RH rear bleeder screw until a stream of brake fluid comes out. While the assistant maintains pressure on the brake pedal, tighten the RH rear bleeder screw.
Repeat until clear, bubble-free fluid comes out.
Refill the brake master cylinder reservoir as necessary.

5.Tighten the RH rear bleeder screw.

6.Repeat Steps 2, 3, 4 and 5 for the LH rear bleeder screw.

7.Place a box end wrench on the RH front disc brake caliper bleeder screw. Attach a rubber drain tube to the RH front disc brake caliper bleeder screw, and submerge the free end of the tube in a container partially filled with clean brake fluid.

8.Have an assistant pump the brake pedal and then hold firm pressure on the brake pedal.

9.Loosen the RH front disc brake caliper bleeder screw until a stream of brake fluid comes out. While the assistant maintains pressure on the brake pedal, tighten the RH front disc brake caliper bleeder screw.

Repeat until clear, bubble-free fluid comes out.
Refill the brake master cylinder reservoir as necessary.

10.Tighten the RH front disc brake caliper bleeder screw; refer to Specifications in this section.

11.Repeat Steps 7, 8, 9 and 10 for the LH front disc brake caliper bleeder screw.



Here is a portion of the ABS system overview from the factory service manual, it appears that the ABS pump is in a 'normally open' mode, allowing brake fluid to flow thru it during normal operation, so bleeding the brake system will also cause new fluid to be introduced into the ABS pump. The only place where 'old' fluid might be retained in the the Hydraulic Control Unit (HCU) accumulator. However Ford does not think that this needs special attention when changing out fluid.

Here is the description of the ABS system:

When the brakes are applied, brake fluid is forced from the brake master cylinder outlet ports to the HCU inlet ports. The fluid pressure is transmitted through three normally open solenoid valves inside the HCU, through the outlet ports of the HCU to the brakes. One circuit of the brake master cylinder feeds the front brakes while the other circuit feeds the rear brakes. If the anti-lock brake control module senses that a wheel (1007) is about to lock, based on wheel speed sensor data, the solenoid valve will pulse closed, preventing more fluid from entering that circuit. The anti-lock brake control module then reads the sensor signal from the affected wheel again. If the wheel is still decelerating, the normally closed solenoid valve for that circuit is opened. A controlled amount of hydraulic pressure between the normally open valve and the brake is relieved into the HCU accumulator. Once the affected wheel returns to vehicle speed, the anti-lock brake control module returns the solenoid valves to their normal condition, allowing fluid flow to the affected brake.

 

Theres no need for all that mess. Start with the wheel furthest away from the master cyl. Just open the bleeder and let the fluid run. You dont have to pump the brakes. Once you have all of the air from that line go to the next furthest wheel away from the master cly. Continue this till you run out the wheels. If your brakes are still spongy then you have other issues going on. Did you bleed the controler it self??...Rob

 

Have bled brakes in not only my '05 FX4, but my '06 F350. The dealer is non-essential for either of these. The abs is strictly an electronic measuring & braking application system.