Extremely hard brake pedal all of a sudden

[Boston GN]

Driving to day all of a sudden my brakes went "out." I have an extremely hard brake pedal, like all the power is gone. No brake lights or anything came on. Shocked the crap out of me when I decided I wanted to stop and my pedal took all my force to put it somewhat down to stop the car. What exact part has gone out? Easy to replace? Is it the whole damned thing?
This is a powermaster set up btw

 

[19gn87]

Rather than jumping to conclusions, guessing, etc., I would first carefully go through this diagnostic tree . Hopefully it will save some headaches and stress (not to mention some money).

 

[GNRick]

When mine did that, the repair manual pointed towards the accumulator (black ball with yellow writing on it). Bought a new one and that didn't fix it. I then bought a new pump from Hank Terry and that did the trick. I know Red Regal T will tell you to convert to vacuum, but I also bought a whole powermonster for my other GN from Autozone for around $300. Check their website. Also do a search for powermaster and decide if a vacuum set up should be in your future. Good luck.

 

[Ash]

there is a possablity that your break accumulator went out. Turn on your ignition but dont start the car and listen for the break motor If you here the motor wine up then you know thats working and your accumulator is leaking. If it didnt make any noise check the fuses to the break motor. then check if you have power to the motor its self with a volt meter if you do then your motor went out. hope this will help you out

 

[Boston GN]

I'll definitely check out that link. Thanks guys. I'm definitely not going vacuum. Sticking with the PM.

One thing I forgot to tell you is that after the brakes went out, I made it to my destination, hung out for a few hours then had to drive back home. Came out and the brakes were fine...for about 5-10 minutes, then back to the hard pedal. Not sure if that help diagnose

Thanks again for all the info here

 

[Red Regal T]

Originally posted by Boston Boy
I'll definitely check out that link. Thanks guys. I'm definitely not going vacuum. Sticking with the PM.

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