How to Bleed Your Vehicle's ABS Hydraulic Unit
If your vehicle's ABS hydraulic unit is acting up, then you need to act fast before it jeopardizes your safety. The ABS hydraulic unit ensures your vehicle's wheels will stop at the same rate by delivering the required amount of hydraulic pressure. When your wheels lock up, the ABS hydraulic unit controls their deceleration rate so that they'll slow down to a safer level. To achieve efficient braking function and prevent wheel failure, you need to bleed the ABS hydraulic unit of your vehicle properly. Here are the tools you need and the steps to follow in bleeding the system:
Difficulty level: Moderate
Tools that you'll need:
- Six-point box-end wrench set
- Clear container
- Fresh DOT 3 brake fluid
- 1/4-inch inside diameter clear vinyl hose
Step 1: Locate the ABS modular unit and take off the rubber cap covering the bleeder valve. Insert a six-point box-end wrench in the valve and attach a 1/4-inch inside diameter clear vinyl hose to it.
Step 2: Put the other end of the vinyl hose inside a clear container and let the brake fluid flow into it. Turn the box-end wrench one-eighth to a quarter of a turn clockwise to do this. Close the bleeder valve tightly once the brake fluid stops flowing.
Step 3: Start the engine and allow it to idle for at least a minute before shutting it off again. Repeat step 2 until no more fluid flows out of the vinyl hose. You may need to do this step three to four times until the valve is completely drained of all fluid.
Step 4: Fill the brake fluid reservoir with fresh DOT 3 brake fluid. Keep pouring until the fluid reaches the max line. Repeat step 2 two more times before topping off the brake fluid reservoir with fresh fluid. Turn the box-end wrench clockwise again and start the engine.
Step 5: Stop the process and close the bleeder valve as soon as a smooth stream of brake fluid flows out of the vinyl hose. Leave your engine idling until the ABS modulator's pump shuts off.
Step 5: Turn off your engine. If the ABS light switches on during the process, shut off your engine and repeat step 5. Check the brake fluid level in the reservoir and top it off as necessary. Lastly, put the rubber cap back on and inspect the bleeder valve to ensure proper operation.
- When pouring the brake fluid into the reservoir, do it slowly to avoid bubble formation.
- Brake fluid can greatly damage automotive paint, so immediately wipe off any spills on the vehicle's surface.