Hydraulic Brake System

Similar the air disc brake system the Meritor hydraulic brake system also uses a retention clip to hold the brake pad in place inside the caliper. By removing a retention bolt the retention plate is removed and the brake pad can be slid out without having to swing the caliper away. If the retention plate is not replaced by the technician after placing new brake pads into the caliper or if the retention plate bolt comes loose and is lost and the retention plate falls away the pads are no longer being held in place. I have talked to several technicians on the issue. To remove the brake pad once the retention clip is removed the pistons may need to pushed back depending if there is any residual pressure still in the hydraulic system. But this is not always the case. If the retention clip is missing the brake pad could work its way out while the vehicle is traveling down the road. The pad may fall onto the roadway or come in contact with the wheel.

Add language in the OOSC criteria to add this type of violation.

In section 1.a.(7)Hydraulic and Electric Brakes: The language currently in the OOSC says, “(a) Missing of broken caliper, brake pad, shoe, or lining. (393.48(a)) My request is to revise the language for 1.a.(7)(a) The wording in the OOSC should be rewritten to say, “(a) Missing or broken caliper, brake pad, shoe, lining, or pad retaining component. (393.48(a)) By changing this wording in 1.a.(7)(a) it would be consist with the wording found in 1.a.(6)(a) which reads: Air Disc Brakes (Exposed pushrods and Direct Coupled – Air Chamber to Caliper) (a) Missing or broken caliper, brake pad, pad retaining component, pushrod, yoke, clevis pin, brake adjuster, parking brake power spring, chamber return spring, or air chamber mounting bolt. (393.48(a))