If the vacuum brake booster is faulty, the force on the brake pedal increases
Therefore, you need to check the operation of the vacuum amplifier
With the engine off, press the brake pedal several times (with an interval of about 5 seconds) and, holding the brake pedal down, start the engine.
The brake pedal should move forward
If this does not happen, check the tightness of the vacuum hose on the intake manifold and on the housing of the vacuum brake booster
You also need to check the operation of the non-return valve
The brake booster vacuum hose consists of two hoses and a connecting fitting.
To check the check valve, you need to remove the hose in which the valve is installed, the hose that is connected to the vacuum booster
We compress the bent ears of the hose clamp to the fitting of the vacuum brake booster with pliers and slide the clamp along the hose.
Disconnect the hose from the pipe of the vacuum brake booster
In the same way, disconnect the hose from the fitting
Remove the vacuum hose from the holder on the cylinder head bracket and remove it
Checking the operation of the valve installed in the cavity of the vacuum hose.
To do this, insert the nose of the rubber bulb into the end of the vacuum hose with which the hose was connected to the vacuum booster, and squeeze the bulb.
Air must escape through the valve.
Releasing the pear. If it remains in a compressed state, then the valve is working. In the absence of a pear, you can blow the valve with your mouth.
If the check valve lets air through in both directions, replace the vacuum hose assembly with the valve
If the non-return valve and hoses are in good condition and their fastening is correct, then the vacuum booster is faulty
Install parts in reverse order
Replacing the vacuum brake booster
If the check revealed a malfunction of the vacuum brake booster itself, then you need to replace it
We prepare the car for the task and remove the battery
We compress the bent ears of the hose clamp to the fitting of the vacuum brake booster with pliers and slide the clamp along the hose.
Disconnect the hose from the pipe of the vacuum brake booster
Remove the master brake cylinder assembly with reservoir
In the passenger compartment under the instrument panel, disconnect the pusher plug of the vacuum brake booster from the pedal
To do this, remove the spring retainer of the pusher fork pin with pliers
Remove the finger from the holes of the fork and pedal
We unscrew the four nuts securing the vacuum brake booster to the bulkhead
We take out the vacuum booster from the engine compartment, removing its rod from the hole in the bulkhead
Inspecting the protective cover of the vacuum booster rod.
If necessary, replace the protective cover by unscrewing the locknut and removing the fixing ring
If the vacuum booster is to be replaced, remove the sealing gasket from the studs of its fastening and install it on the new booster
Install the brake booster and all removed parts in reverse order
If necessary, adjust the position of the brake pedal, as described in the article "Mazda 6 brake design features "
The rubber ring of the brake master cylinder needs to be replaced
