FEW PEOPLE KNOW that this FAILURE in the VACUUM PUMP or BRAKE DEPRESSOR can be VERY EXPENSIVE!!

Do this test, which is used to easily check if the check valve in the vacuum pump or brake vacuum pump fails, since this failure will damage other parts of the engine, because oil will end up coming out of the engine through there, since the oil reaches the vacuum pump to lubricate it and it will end up entering the vacuum circuit and this, in addition, will cause the brake pedal to be hard and there will be difficulties in braking, among other things...