Foot to floor and heart rate through the roof…why aren’t we stopping. No brakes even at low speeds can be alarming. Changing brake pads isn’t a difficult job but it is important to follow correct procedures. In this post, we’ll solve your problem.
The top two common causes of no brakes after changing brake pads include:
- Incorrect brake pad bed in procedure
- Air in the brake system
In this post you’ll learn the common causes of no brakes after pad change, you’ll learn how to diagnose your brake problem and how to fix it.
1 Incorrect Brake Pad Bed-in Procedure
Brake pads ride close to the rotor ready to apply force at the touch of the pedal, new pads won’t naturally take up this position after a brake job, they need to be prepped.
Part of the process of fitting the brake pads is as you know pushing back the caliper pistons. When the pistons are fully retracted they allow for the extra space needed for the new fatter brake pads.
As the caliper pistons are fully retracted, the excessive free-play between the new pad backing and the caliper piston must be removed. Failing to remove the gap will cause the brake pedal to sink to the floor with little or no braking capability.
In addition, the friction surface of the brake pads needs to mate with the rotors, and until they do, braking efficiency will be poor.
Lack of performing a proper break-in procedure is a cause of no brakes after replacing brake pads.
(Using excessive amounts of brake lube will contaminate the brake pads, cleaning the pads will resolve this type of issue.)
Bedding in the brakes isn’t difficult and doesn’t require any tools or much effort.
Pump brakes – pump brakes several times until the pedal is firm. This action closes the gap between the caliper piston and pads. Failing to close the piston to pad gap before driving is dangerous.
Test drive – With a firm pedal, test drive the vehicle at low speeds about 30-50 mph and brake lightly. Heavy braking risks overheating and damaging the brake pads. The brake pedal will begin to improve and after 5 to 6 applications the pedal will feel normal.
2 Air In The Brake Lines
Some brake pad fitting techniques may instruct the opening of the bleed nipple when retracting the piston. This technique prevents potentially contaminated fluid from moving into the master cylinder and requires bleeding the system afterward.
If the hydraulic system is opened, it must be bled. Air in the system will cause a low pedal with little or no bite.
Brake Bleeding Procedure
There are several different ways to bleed your brake system, but by far the easiest and most reliable is the vacuum brake bleeding tool. This is a one-man job and requires only a basic bleed kit.
Check out Brake repair tools page for a simple and inexpensive brake bleed kit and if you need brake system parts, check out great deals on brake resources page useful, it’s a fluff-free guide to DIY brake repairs.
Can I drive on grinding brakes? Grinding brakes are caused by worn brake pads or debris trapped between the rotor and caliper. Driving on grinding brakes is a safety hazard. Brake performance is reduced and brake components such as rotors and calipers will be damaged.
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John Cunningham is an Automotive Technician and writer on Rustyautos.com. He’s been a mechanic for over twenty-five years and has worked for GM, Volvo, Volkswagen, Land Rover, and Jaguar dealerships.
John uses his know-how and experience to write fluff-free articles that help fellow gearheads with all aspects of vehicle ownership, including maintenance, repair, and troubleshooting.