Know how to Bleed your car's brakes @PartsAvatar Canada

Brake bleeding is a repair job that must be done throughout the life span of a car. Parts avatar advises to bleed your car’s brakes every two or three years.

Whenever our mechanic advises to bleed the car’s brakes, we often ignore it. It is not like we are waiting for our car to break down. So why not give it a go now rather waiting for the damage to occur. Most automobile manufacturers advise to bleed your vehicle’s brakes every three years. As the fluid’s heat resistance reduces by time, it can cause brake system to corrode. So it is necessary to bleed the brakes to get optimum performance out of brake system.

Before moving further, let’s know what is bleeding of brakes and why it is necessary.

Basically, when we are bleeding the brakes, we are actually removing air out of hydraulic brake lines of car. Air makes its way through leaks in brake system components. Brake fluid’s heating resistance decreases by time as over the period of time it absorbs water from atmosphere. Due to friction, caused by heavy braking, fluid heats up thus turning water into steam. Air leaking in the brake lines makes the pedal spongy, and in worst cases the brakes may fail completely.

Before starting bleeding process, it is essential to check the brake system parts for leakage. If you find a leak, replace the faulty component immediately. Entire braking system is like a closed compound so if the fluid level is low, that means there may be a leak in master cylinder. So fix the leak first. Front and rear Brake pads of car wear out frequently so they may also cause air to enter the brake system. Brake pads should also be replaced if necessary.

PRE - BRAKE BLEEDING PREPARATIONS

Have all the tools prepared beforehand. For the full replacement of the fluid in the brake system you will need at least three cans of brake fluid. 10mm box wrench for disc brakes and 8mm box wrench for drum brakes can be used if necessary. You will also need one way bleeder screws, pressure brake bleeder and vacuum brake bleeder to bleed the brakes. No matter what method for bleeding you use, same tools are used.

Before you plan to bleed the brakes, loosen the bleeder valves by applying the penetrating oil. 

When you place the vehicle on the jack stands, on the day of bleed, after removing all four wheels, tighten one lug nut against rear and front disc brake rotor of car's brake system and place a square object to keep the brake pedal from falling to the floor when you start bleeding. Mostly you have to bleed the brakes several times, so keep the equipments ready with you. 

If you see the traces of air in the system, bleed it again until there is no air and fluid is flowing clearly inside. Also the fluid to be used for bleeding should be manufacturer’s recommended. There are DOT ratings specified by the manufacturer. Not every vehicle runs on same brake fluid of car so check owner’s manual before buying any fluid.

THE BLEEDING TASK

In bleeding task you can either do it yourself or can take help of your friend.

Step 1

Jack up the car and secure with jack stands. Now remove all the four wheels.

Step 2

The next task is to locate the bleeder screw and spray them with penetrating oil. Find the proper wrench that fits the screw and loosen the screw. Using proper wrench could decrease chances of screw’s hex head going round. If the screw is stuck, you can spray penetrator like WD- 40. After doing so, retighten all the screws again.

Step 3

Now, the fluid level in the master cylinder should be checked. If the fluid level is lower, then add more fluid level up to the mark. This process should be done at frequent levels because its level drops as the old fluid is drained off. Filling it to the top is necessary because if the reservoir empties, air will get into the system and you will have to repeat the whole task to release the air out. Always use manufacturer’s recommended fluid. Using any other fluid may damage the brake system as not every fluid is compatible with every brake system. Do not spill the fluid because it penetrates easily.

Step 4

You must keep owners manual with you. The sequence of bleeding the brakes differs from one car to other. This information can be found in owner’s manual. In some cars, the most distant brake from the master cylinder of car is bled first. For example, if you ware bleeding a rear wheel drive vehicle then start with right rear wheel, then move to the left rear wheel; then move it to the right front wheel and eventually to left front wheel.

Step 5

After bleeding each brake properly and adding fluid to the master cylinder, pump the brake several times when the car’s engine is off with the help of a helper. Brake pedal should no longer feel spongy when you press it. If there is still spongy feeling coming while pressing the brake, master cylinder and bleeder screws must be checked again.

Step 6

When your helper maintains pressure on the pedal, open the bleeder screw a small amount. The fluid will pass through the clear tube and the pedal will begin dropping towards the floor. When your helper signals you for “floor”, close the bleeder screw. Also check the fluid level again.

Repeat the process of pumping the brake, opening the bleeder screw and closing it, several times until the stream of fluid flowing is free of air bubbles. After every five times the brake pedal is depressed, top off the master cylinder reservoir with fresh fluid. Do not let the air enter the master cylinder in any case.

Repeat these steps on the remaining three brake locations in the sequence instructed in your owner’s manual. If there is fluid eruption, there may be some air bubbles still trapped in the system.

Step 7

Visually inspect all the bleeder screws for any signs of leakage. Check that all the bleeder screws are tight. Put the tires back on. Test the brakes before heading out onto the road.

To test the brakes on the road, wait until there is no traffic, drive slowly and press brake pedal as you would normally. The car should pull up quickly and the pedal should not feel spongy.

Now your brakes have been properly bled.

There are several ways to bleed the brakes like pump and hold method, vacuum method and pressure method. So you can choose whatever method you want to provided you successfully the air out of the brake system. You can consult your owner’s manual if you find difficulty in locating the components of brake system.

For other brake system part’s aftermarket purchase, do not forget to visit Partsavatar.ca