I just had to disassemble my HCU to clean a bunch of the rubber from the old vibration isolation lines that run from the combination valve to the HCU and had to replace the dry rotted motor lead. I noticed Quite a few people had asked over time, "How to bleed the ABS without a DRB III. There are two ways to accomplish this. The total electric method and the mechanical method. They both do essentially the same thing. I prefer the mechanical method because it is faster easier.
What you need:
Thanks,
What you need:
- Your normal tools for which ever brake bleeding method you prefer.
- A set of jumper leads
- A fuse holder with 5-amp fuse (ABS Pump motor calls for a 20-amp but the system will not be under load)
- A remote starter button (Optional)
- Torx driver T-25 I think and a T-45
- A Bar magnet. I used this one as it was both strong enough to actuate the solenoid and the perfect length to rock between the intel and outlet or actuate both at the same time.
- Disconnect the negative battery terminal.
- Remove the control/solenoid coil unit from the HCU. That’s where the Torx driver comes in. Four screws. Lay it to the side.
- Disconnect the 2-pin plug that leads from the HCU Motor.
- Connect the jumper lead from the negative battery terminal to black wire pin going to the HCU Motor.
- Connect the fuse holder to the positive terminal, through the remote start switch to the Brown/Wt pin going to the HCU Motor.
- Connect you collection bottle and open the bleeder screw on the passenger-side front. This is the longest run on the on the Primary hydraulic circuit. The Brakes are two separate circuits that share a reservoir. The fluids can exchange in the combination value and the HCU oscillator chamber but that’s just seepage for lubrication.
- Use your bleeding method until you get fluid from the bleeder. Leave the bleeder fully open.
- (Optional only if the HCU was disassembled) Remove either of the two Torx plugs on either side of the housing. Carefully remove the pump plungers, (there is a tiny metal check valve ball that can be easily lost) Fill oscillator chamber with fluid.
- Place the bar magnet across the inlet and outlet solenoids for the current line. If in doubt, follow the brake line to the bleeder. (The solenoids line up with the corresponding break lines vertically.) The top one for any give circuit is the inlet from the combination valve to the break line. It is normally open and allows the brake fluid to go straight to the brake bypassing the abs pump. When energized it switches the flow from the combination valve to the ABS pump and stops the flow from going directly to the brake. The bottom valve switches the outlet flow of the abs open and closed. To remove all the air in the system both valves must change position.
- With the bleed er still open, and the pump running, rock the magnet so that it opens and closes the upper and lower valves. This can be achieved electrically but is far simpler manually. Try to have the magnet touch one then then just the other. This creates a surge that forces the air out. (The pump motor must be run, in while bleeding to fully remove the air in both the pumping chamber and oscillation chamber. The oscillating chamber has a high point that has no venting.)
- Stop the motor. Close the bleeder. Move on to the next and repeat. The Order for ABS bleeding Is front Passenger followed by front driver then rear passenger side. ABS Bleed of the rear driver side is not needed.
- Bleed as Normal.
Thanks,
