Help troubleshooting power master.

[V6POWER]

My power master quit working (hard pedal) and I am trying to trouble shoot the problem. The brake motor does not run and I need a good pressure switch to try to see if it is the problem. Does anyone close to Mebane, NC have one I could borrow? Mebane is just east of Burlington. Thanks for any help.

 

[V6POWER]

It is not the switch, so I don't need to borrow one.

 

[ncgreg231]

If the unit has more than a few years/miles, the motor has probably burned out and needs to be replaced. The fuse (30A) is probably burned out, if you replace it, it should run for about a week, and then burn out again. Each time you replace the fuse, the time till the next burn out will be a little bit shorter.

I would recommend to make the switch over to a standard vacuum system (I think gnttype has a "how to") or get a complete replacement unit from advance auto parts. You might even get a "lifetime replacement" warranty although it's manager's discretion (I got one free replacement) This should be the complete unit (master cylinder w/ motor, switch & accumulator) for about $250 - it's not a genuine GM original (I believe it's a reman unit) but it will work very well. I've never priced the genuine GM unit but I hear they normally go for about $800. HTH.

-Greg

 

[ncgreg231]

Oh yeah, use a jumper wire to try and "hot wire" the booster motor. Use the wire harness that connects to the pressure switch (should be three wires) With the ign "on" one should have 12V. When connected to the 12V, one wire should turn on the "brake" light on the instrument panel, the other wire should turn the booster motor on. You might still have a bad switch, but I'm still betting on a burned out motor. I've have three motors burn out on me between my two cars, so that's why I'm expecting your motor to have burned out also...

 

[V6POWER]

I am converting to vacuum brakes and the system should be here this week. Thanks for your very informative response. I really appreciate it.