Drain the oil from the system (see "Changing the GAZ-3110 hydraulic booster oil")
Remove the pump drive belt. At the same time, we check its condition and degree of wear. If necessary, replace the belt.
We loosen the clamp with a screwdriver and remove the fluid supply hose to the pump.
Using a 17 key, we unscrew the discharge hose fitting from the pump.
Using a 17 key, we unscrew 2 bolts securing the pump to the bracket and remove the pump.
Install the pump in reverse order.
After that, we adjust the tension of its drive belt.