Thanks for that, but when the hose is off the pump and engine running there is very little suction,a gentle lifting of the finger tip skin. You mention booster filter where do i find that?

does any one know what the vacum pressure should read on tick over?

I have a problem with the vacuum pump for the brake servo it does not suck as it should I have changed it and get the same result which means the brakes are not very good, any suggestions?