Brake Booster Repair Tips
Brake booster repair may become necessary on vehicles that have a power brake system installed. These types of brakes can easily be identified by looking for a round black cylinder at the back of the engine on the drivers side of the vehicle. This device actually takes the work off the driver's legs and feet from pushing in the brakes mechanically, by using your vehicles vacuum pump system to apply mechanical pressure to the brakes instead of by manual force.
When it is Hard to Apply the Brakes
When it is hard to apply the brakes, it is likely an issue with your brake booster or the vehicle's vacuum system. Before preforming a brake booster repair you will want to be sure that the booster is working properly, or if the issue is coming from your vehicle's vacuum system, not delivering the air your booster needs. If your brakes are hard to depress, it is likely a booster issue. You can rule out the vehicle's air system with a quick test of the booster's vacuum before going further.
Check your Boosters Vacuum
To check the pressure in your brake system, bleed out all the fluids from the system with the engine off. Then with the brake petal slightly pressed turn the engine back on. If your vacuum is working properly, the brakes will refill from the reservoir. If the fluid does not auto fill into the brake system after you have drained and refilled it, the problem is likely your vehicle's vacuum pump, not the booster itself.
Replace the Check Valve
If you have determined that the booster is bad, you will want to remove the unit and begin a brake booster repair. Be sure that during this repair process you replace the check valve. At the point where the brake line attaches to the booster you should see clamps holding the valve to the line and to the booster itself. Remove the clamps and use a wrench to take out the check valve, taking care not to allow debris to enter the chamber as you work. A check valve works as a basic back pressure release that utilizes not only your vehicle's vacuum pressure but also the brake fluid system itself.
Standard Brake Part Replacement
While doing the repair make sure that your emergency brakes are on and that nothing drops into the lines that could cause blockage down the road. Once the booster has been removed and repaired, or removed and replaced, you will want to start up the vehicle and ensure that the system is refilling with brake fluid as normal. If your booster is still not functioning properly, it is likely an issue with the vehicle's vacuum pump system not sending the proper pressure needed to make the booster work properly. If the brakes still push hard and the lines do not fill as expected, you will then need to check and fix your vacuum system as it is likely the source of the problem.