i was out driving this week and i have develop a squeak when pushing the pedal , i have tried to lube things on what i see , i think it might be on the inside ? i never took a booster off the master cylinder before ,, i just dont know, its not the pedal pivot,,its kinda like a air sound too ,, i have great breaks ( power ) ,, do i need to take the booster off the cylinder ??
i called them to day and they want me to check the check value ,, it was fine , no leaks , i did the test on it and while it was not running it made the sound until it pumped up and it stopped , after i started it up and it sucked more air it started to make the sound again ,, so i guess i call them again
Check valve is cheap and easy to change. Check rubber seal it plugs into and vacuum hose for cracks. I've never seen a booster itself develop a crack or leak unless over tightened when installed. Do you have a dual diaphragm booster? If so maybe one diaphragm is ruptured?