Brake boosters for these models of Indus Corolla (Diesel and Petrol Version) are more or less same.
In petrol vehicles, brake booster receives the vacuum from its intake manifold.
In diesel vehicles, brake booster receives vacuum directly from the pump which is mounted on the rear side of alternator in order to make sure the constant supply.
Firstly there is desi method to check the vacuum at booster by removing its rubber pipe from booster and place your finger tip on it. If its working, then you will know it with its -ve pressure. It will try to gently suck your finger tip.
And if its vacuum pressure (-ve pressure) is felt there, then follow this method.
Stop the Engine and press brake pedal several time untill you feel it is up and hard.
Put your foot on brake pedal and start the Engine, Pedal should go down a little bit or should feel softer.
If this happens, your booster is working fine.
