GT4 break servo not properly working

Recently I realized that when I break, loose the pedal and brake again within half a second, the break servo seems not to work (pedal stiff, nearly impossible to block the wheels). If I wait more than a second, everything is fine again and the break works properly. I had not time to diagnose so far but could this be a faulty vacuum hose? Where does the servo get the vacuum from? Intake manifold with a long long hose?

Regards
Harry

If you have Booster assist on the first pump of the brakes then it sounds like the system is working. Thereis a check valve in the engine compt. with a hose attached to left rear intake manifold. from the factory all 4 manifolds were tied together with small pipes to increase availible vacum...generally these tubes are found bypassed and plugged, if the throttles are too far open at idle this can also reduce vacum. Make sure someone hasn't replaced the non collasable brake vacum hose with collapsable heater hose..can make a big difference.

Regards, JRV

Thank you! I will have a close look at it.

Regards
Harry

Brake issues have always caused some trouble for me on certain cars. On my 308 I thought my brakes required a little too much effort to stop. I tried everything check valves, pads, various vacuum tests, fluid changes, etc. and they still require more effort than I would like.