Overhaul of pneumatic wheel brakes. The pneumatic wheel brakes differ from the hydraulic wheel brakes. The brake shoe of the air brake is opened by the cam, so the cam and the end surface of the brake shoe will be worn. When the wear is too large, the pressing force of the brake shoe to the brake drum will be lowered to affect the braking performance.
The surface of the brake cam is unevenly worn, grooved, etc., and is repaired after surfacing. When the brake shoe end face is severely worn, a metal jacket can be placed. If the cam journal wear is too large and the bracket hole is loose, the shaft can be plated or surfacing, brushed, etc. or replaced. The clearance gap between the front camshaft and the support hole of the CA1091 type car is 0.025~0.040mm, and the clearance gap between the rear camshaft and the support hole is 0.031~0.80mm.
Maintenance of hydraulic brake system transmission parts
(1) Inspection and repair of hydraulic brake master cylinder and wheel cylinder. When the cylinder wear and piston fit clearance is greater than 0.10mm, the piston is replaced. When the cylinder wear is greater than 0.12mm or the roundness error is greater than 0.125mm, the master cylinder or wheel cylinder can be repaired or replaced.
The cups in the master cylinder and the wheel cylinder and the oil valve in the master cylinder are not replaced as required. The springs in the master cylinder and the wheel cylinder are skewed, the spring force is insufficient or the breakage should be replaced.