This is our fourth, and final blog post, on front wheel brake inspections. If you have missed the previous posts on this topic, you are able to find them on our Blog.
Notice that this pad is very worn yet the wear indication is still a few thousand miles from starting to contact. Don’t just rely on wear indicators to tell you when your customer’s pads need replacement. Pad thickness should be visually checked at least once a year and more often when the pads are in their last 20-30% of their life.
If you find the inner pad to have substantially more material on it than the outer, it’s an indication that the sliding function of the caliper is stuck in the outward pad apply mode. Likewise, if the inner pad is worn more, it’s an indication that the caliper is not sliding and applying the outer pad.
Inspect the pad mounting hardware. Don’t just pop it out and throw it away. Look for bent tabs indication improper pad installation and spread tab clips indicating reuse of old hardware on a previous pad replacement.
The rust and corrosion alone on the bottom side of this hardware clip is reason for its replacement. New hardware is coated with a rust preventive coating but it usually doesn’t last the life of the pads. This is why many techs coat the hardware clips with sliding caliper grease. It lubricates and prevents rust and corrosion for forming.
The bolts holding the caliper bracket itself usually have some type of thread locker (Loctite) product on them. For this reason, an impact is the tool of choice to remove them. Remember to put some thread locker back on the threads when reinstalling the bolts.
Caliper mounting brackets can become worn in the area where the pads are mounted or they can require replacement for other reasons. Caliper brackets are frequently available through a wide range of brake suppliers. They are no longer just O.E. items.
This caliper/pad mounting bracket requires cleaning before it is reused. New pads installed, even with new hardware, will be restricted in their movement because of the rust and scale present in the pad ear mounting area.
Removing a dust cap is really a reflection of your level of professionalism. Use a proper tool, which is not a hammer or a hammer and screwdriver. Properly removed and reinstalled, a dust cap should not have a mark on it.
Looking at the nut and cotter key under the dust cap you get an indication that the bearings are most likely in good condition. The grease is clean, not broken down from overheating and there is no evidence of anything but previous professional service.
After removing the cotter key and nut catch the outer bearing in a rag and wipe if down. Look at the rag for any indication of bearing failure, small metal particles or other foreign material.
On this vehicle there was an ABS light that would occasionally come on. No codes were ever found. Looking at the tone wheel on the inward side of the hub you can see a possible reason. The teeth of the tone wheel are covered with grease residue and brake pad material. This in a very possible reason for the occasional ABS light.
This was out last installment on our Front Wheel Brake Inspection.
Next month for our Tech Tricks Tuesday, we will cover Relining Front Brakes.
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