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How to Test and Troubleshoot a Brake Caliper Installation
If you’ve never rebuilt or installed a brake caliper before and have just done so, it’s highly recommend that before you drive the vehicle that you test your installation and troubleshoot any problems you may find. This guide will give you several tests or inspections to perform to ensure that you have a correct and trouble free brake system repair and installation.
- Check the system for leaks.
- Check the system for air bubbles.
- Make sure the stop squeak brake adhesive was applied to the metal part of the pads.
- Make sure all caliper hardware was reinstalled correctly.
- Make sure the brake master cylinder is filled with clean fluid of the proper DOT grade.
Leak Check
Have a friend start the vehicle and press and hold the brake pedal securely while you check each wheel for leaks. Your friend should also be checking to make sure the pedal doesn’t get hard when first pressed and then slowly go farther down towards the floor while it’s being held. If this happens, the brake master cylinder is doing what’s known as bypassing, and needs to be replaced.
Air Bubble Check
Air in the brake lines is bad for two reasons. The first one is that since air is compressible and fluid is not, it will take more pedal pressure to apply the brakes properly. The second is that brake fluid is hygroscopic, or it absorbs water from the air. This will cause it to break down as well as cause rusting of critical brake components, possibly causing failure.
Special Brake Pad Adhesive
Making sure that the special brake pad adhesive was applied to the metal backing plates of the pads isn’t a critical item, but if the brakes are squeaking, not having it is one of the two main causes. Going hand in hand with this test is to remember during assembly and before applying the glue, to take some 120 grit sandpaper to the sharp corners and edges of the pads and chamfer them somewhat. You don’t want to take much material off, just enough to get rid of the sharp edges on the pads. This will stop the pads from catching grooves on the rotor and “singing” or squeaking.
Caliper Hardware
Caliper hardware encompasses all of the following items:
- Retaining springs
- Anti-squeal springs
- Bolts and nuts
- Anti-squeak shims
- Retaining pins
Retaining springs and pins usually go together. Each caliper has two of each. The pin retains the pads and the spring retains the pin. Anti-squeal parts are those that go between the caliper piston and the pad backing plate and the backing plate and the outer caliper arms. They keep the pads from being able to vibrate, which cause squeaks and squeals. Make sure the nuts and bolts that hold the caliper to the steering knuckle are properly torqued.
As long as you perform the above tests or inspections after performing front disc brake caliper repair, you will have many years of safe and reliable operation of your vehicle’s brake system.
