There is a special procedure to bleed the brakes on these trucks. I don't have access to the FSM at home but I searched around and found it. I would also do a little research on your own via other forums for tips etc, it is important to very slowly depress the brake pedal and hold it for a while for each stroke when initially releasing the pressure from the accumulator (step a). The rears should constantly pump with the pedal depressed when you get to that step. Most importantly do not let the reservoir go dry or you will need the Techstream to bleed it properly.
BRAKE FLUID: BLEEDING
NOTICE:
Wash off brake fluid immediately if it comes into contact with a painted surface.
If the brake pedal is depressed with the reservoir cap removed, then
brake fluid will spatter. HINT:
If any work is done on the brake system or if air in the brake lines is suspected, bleed the air from the system.
When bleeding, keep the amount of the fluid between the Min. and Max. lines on the reservoir.
FILL RESERVOIR WITH BRAKE FLUID
Fluid:
SAE J1703 or FMVSS NO. 116 DOT3
BLEED
BRAKE BOOSTER W/ACCUMULATOR PUMP ASSEMBLY HINT: Perform this step only if the
brake booster with accumulator pump assembly is removed and/or installed.
(a) Turn the ignition switch OFF, depress the brake pedal 20 times or more to release the pressure from the accumulator.
(b) Fully depress the brake pedal 10 times.
(c) Turn the ignition switch to the ON position and start the
brake booster pump.
(d) Make sure the pump operates for 8 to 14 seconds.
If the pump does not operate as specified, repeat steps (a) to (c) and recheck the operating time.
BLEED BRAKE LINE
(a) Front brake line
(1) Turn the
ignition switch to the ON position and wait until the pump motor has stopped.
(2) Connect the vinyl tube to the brake caliper.
(3) Depress the brake pedal several times, then loosen the bleeder plug with the pedal held down.
(4) At the point when the fluid stops coming out, tighten the bleeder plug, then release the
brake pedal.
Torque: 11 Nm (112 kgf-cm, 8 ft-lbf)
(5) Repeat (3) and (4) until all the air in the fluid has been bled out.
(6) Repeat the above procedures to bleed the other brake line.
(b) Rear brake line
(1) Turn the
ignition switch to the ON position and depress the
brake pedal.
(2) Connect the vinyl tube to the brake caliper.
(3) Loosen the bleeder plug and release air.
HINT: Brake fluid is sent through the pump, so keep the brake pedal depressed until the air is completely bled out.
(4) When the air is completely bled out of the brake fluid through the bleeder plug, tighten the bleeder plug.
Torque: 11 Nm (112 kgf-cm, 8 ft-lbf)
(5) Repeat the above procedures to bleed the other brake line.
BLEED MASTER CYLINDER SOLENOID HINT: Perform this step only if the master cylinder solenoid is removed and/or installed.
(a) Connect the Techstream to the DLC3.
(b) Turn the
ignition switch to the ON position.
(c) Select "Active Test" mode on the Techstream.
(d) Connect the vinyl tube to the rear brake caliper.
(e) Loosen the bleeder plug.
(f) Select "TRAC Solenoid (SRMF & SRMR)" to drive the
solenoids and bleed air from the rear brake caliper.
NOTICE: Do not depress the brake pedal.
HINT:
Brake fluid is sent through the pump.
To protect the
solenoids, the Techstream turns OFF automatically 2 seconds after every
solenoid has been turned ON.
(g) Repeat step (f) until all the air in the brake fluid is bled out.
(h) When the air is completely bled out of the brake fluid through the bleeder plug, tighten the bleeder plug.
Torque: 11 Nm (112 kgf-cm, 8 ft-lbf)
(i) Repeat the above procedures to bleed the other brake line.
(j) Turn the ignition switch OFF.
(k) Turn the ignition switch to the ON position.
(l) Clear DTC See: Antilock Brakes / Traction Control Systems\Testing and Inspection\Reading and Clearing Diagnostic Trouble Codes.
