Most brake comebacks result from not paying attention to detail when performing the job. Taking a few extra minutes when performing the service will help eliminate the vast majority of come backs. It sort of follows the old saying “pay me now or pay me later”. The difference is paying now involves only a few extra minutes per job and paying me later involves a few extra hours. Below is a list of one great way to ensure a brake job well done:
1 - Bleeding
Where possible, open the bleeder when retracting caliper piston. The brake hose can also be line locked as an extra precaution (use only approved line locks). These steps will prevent back flushing dirty fluid through the system. If it is not possible to open the bleeder screw, push the caliper piston in slowly to prevent building back pressure. Taking approximately 60 seconds to push the piston back in will reduce the back flush pressure to a safe level. When using this step it will be necessary to drain some fluid from the master cylinder reservoir. Either step will reduce the chances of potential damage to the ABS modulator, brake valves or master cylinder.
2 - Check the Brake System
Check all hardware and replace as needed. Weak or worn hardware is a leading cause of uneven and premature pad wear. Restoring the hardware to proper working condition will help to ensure even pad wear and longer pad life.
3 - Cleaning
Clean and lubricate all contact points. Metal to metal contact points should be lubed with Moly Lube. Only a small amount is needed to do the job correctly. Metal to rubber parts should be lubed with a high quality silicone lube. The silicone will not damage the rubber parts and helps to form a moisture barrier.
4 - Machining
If resurfacing the rotor(s) use proper machining techniques and make sure the lathe is in good working condition. On hub-less rotors make sure to clean the mating surfaces with an appropriate tool. Scratch cut all rotors to ensure accurate setup. Always use sharp bits and a vibration damper when machining. After machining apply a non-directional finish using 120 grit drywall sandpaper on a rubber sanding block for 60 seconds per side.
5 - Installing
Clean the rotor before installing on the vehicle to prevent machining dust from contaminating brake pads. The best method to accomplish this is to use a mild soap and water solution. Wash both friction surfaces and wipe dry with a clean lint free rag or paper towels. If using brake cleaner, use a little more than usual and wipe the surface with a clean lint free rag or paper towel while it is still wet. NEVER use petroleum based cleaners because they leave residue.
6 - Hub-less Cleaning
Before installing hub-less rotors, clean the hub mating surface using an appropriate tools(s). Failure to properly clean this surface can prevent achieving the proper install runout.
7 - Indexing
When installing new or machined hub-less rotors the installed runout should be checked. Using spacers on the studs tighten all lugs to the proper torque using the correct sequence. If runout is not less than manufacturer’s specification, index the rotor on the hub to achieve the lowest amount of lateral runout. Before indexing mark the high spot on the rotor and hub. Indexing involves removing the rotor and rotating it one or two lugs and re-installing. Repeat this until the installed runout is below specification. If runout is out of specifications and does not change as the rotor is rotated check to see if the hight spot moves with the rotor or stays with the hub. Failure to install the rotor with installed runout less than manufacturer’s specification is the leading cause of reoccurring pulsation comebacks
8 - Torque
Properly torque the wheel lugs using either a hand torque wrench or torque stick sockets. When torquing wheels use a step torque process. To step torque the lugs tighten all lugs to half the normal torque using proper sequence and then fully torque lugs using same process. Make sure your impact has been calibrated before using torque sticks.s
9 - Test Drive
Test drive the vehicle to ensure proper operation and to break the new friction in. To break the friction in make 10 to 20 stops from 30 M.P.H. down to about 10 M.P.H. Allow about 30 seconds in between each stop for cooling. This process will properly mate the new pads to the rotor surface.
10 - Return Vehicle
Deliver the vehicle and instruct the customer that they should try and avoid panic stops and not tow heavy loads for the first 200 miles.
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