Tips for the correct replacement
of brake discs and drums
As important as selecting quality products is installing them correctly. Therefore, Fremax experts recommend you the folowing procedures to install discs and brake drums with maximum safety.
Remove the old drum. Use a caliper or a micrometer to measure the inner side of the drum to make sure that it is not larger than the maximum allowed diameter. The maximum allowed diameter is engraved on the part and is also available at the catalog. Also check the braking surface for uneven wear, roundness, cracks, and hard blue spots.
TIP: never assembly new linings or brake shoes on uneven braking surface, this will cause brake inefficiency. If the inner diameter of the drum is less than the maximum allowed diameter, it can be machined by a service technician. If not, it must be replaced.
Check the brake linings condition, watching out for wear, cracks, glazing, contamination by grease and/or brake fluid. Also check the warpage, deformation and oxidation of the brake shoes.
TIP: The brake shoes should be replaced every 60,000 km (35,000 miles), or after the replacement of two sets of brake pads in the front axle. Extending the use of them for longer periods will compromise the brake system efficiency.
Check the wheel cylinder, it can’t be jammed or leaking brake fluid, and the bleeder can’t be broken or clogged.
Important: Even when you can’t observe any defect on the wheel cylinder you need to mesasure its piston diameter. If a wrong diameter of cylinder is assembled, braking efficiency will be affected and safety compromised. Whenever replacing wheel cylinders observe the measure specificated at service manual of the car.
Brake drum systems are equipped with manual or self adjusted mechanisms. The inspection of the adjustment system is crucial. The return springs of the brakes shoes should have regular pressure and be free of rust. Also check the actuation of parking brake, hoses and hydraulic lines.
-Use water and mild detergent to clean the system. Never use petroleum based brake cleaners.
-Always reassemble the brake drum system in the reverse order of disassembly.
- Lube the points of contact between brake shoe and mirror to prevent noise; never use universal or bearing grease.
-As there are several brake drum designs never disassemble both sides at the same time to avoid losing mounting scheme, and run the risk of reassembling it wrongly. In case of doubt or difficulty refer to the other side.
-Before testing the vehicle perform the initial adjustment of the brake drum system. Do it thru the adjustment system, never thru the cable of parking/emergency brake (the drum should spin freely, with slight contact with the brake shoes). A properly adjustment will automatically set the course (height) of the parking brake lever.