91gtp Posted November 10, 2007 Report Share Posted November 10, 2007 Ok, Car is a 1991 gp with the 3.4 dohc and 5spd. So everytime i press the brake pedal i hear this noise. it is like a loud humming. Kinda similar to the sound of the fuel pump when you first turn the key, but louder. Also, when i hear that noise the volt gauge goes down about half way then comes back up. And if i hold the brake pedal down, (like at a stop light) i will hear the hum for 2 sec, then it will stop for a couple seconds, then come back. I think i found where it is coming from. its from something on the firewall i think. It is located a little bit below and to the left of the master cylinder. It has a yellow sticker on it that says something about gas under pressure another view close up I also found this thing. it was just sitting on top of my tranny not connected to anything. Anyone know what either of these things are, or what they do. I am trying to get all my problems fixed on this car so it will be a good daily driver. Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted November 10, 2007 Report Share Posted November 10, 2007 The humming noise you are hearing is most likely your PowerMasterIII brake master cylinder/booster. Some cars came equipped with this special brake cylinder booster. Some are louder than others, but that is most likely what you are hearing. I just looked at your pics, and you have a PowerMasterIII- that is what is making the noise, no need to worry it is normal. Quote Link to comment Share on other sites More sharing options...
91gtp Posted November 10, 2007 Author Report Share Posted November 10, 2007 is it normal for the volt gauge to fluxuate when the brake pedal is down becuase of the powermaster 3? Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted November 10, 2007 Report Share Posted November 10, 2007 Yes, it is. When the pump motor runs, it will draw a current in the electrical system, and you will see the drop on your gauge. It will be a much more noticeable drop if your battery is on its way out. The headlights would actually dim when the PMIII pump motor ran on my 90 GP- it had a bad battery though, after I replaced the battery, the dim was less noticeable. Quote Link to comment Share on other sites More sharing options...
91gtp Posted November 10, 2007 Author Report Share Posted November 10, 2007 cool, thats one problem down. thanks Quote Link to comment Share on other sites More sharing options...
1990lumina Posted November 11, 2007 Report Share Posted November 11, 2007 That yellow thing is the accumulator I believe. Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted November 11, 2007 Report Share Posted November 11, 2007 That yellow thing is the accumulator I believe. Correct. Quote Link to comment Share on other sites More sharing options...
GutlessSupreme Posted November 11, 2007 Report Share Posted November 11, 2007 Powermaster 3 brake system info: http://www.kazmotorsports.com/tpsgarage/TGP/brakes/powermaster.htm that other thing looks like the remains of the base of the kickdown cable...? maybe. Quote Link to comment Share on other sites More sharing options...
Regal_GS_1989 Posted November 11, 2007 Report Share Posted November 11, 2007 Powermaster 3 brake system info: http://www.kazmotorsports.com/tpsgarage/TGP/brakes/powermaster.htm that other thing looks like the remains of the base of the kickdown cable...? maybe. x2 My guess is that the car was originally an automatic. Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted November 12, 2007 Report Share Posted November 12, 2007 Powermaster 3 brake system info: http://www.kazmotorsports.com/tpsgarage/TGP/brakes/powermaster.htm that other thing looks like the remains of the base of the kickdown cable...? maybe. x2 My guess is that the car was originally an automatic. That or my guess, is the remains of a hood cable? Quote Link to comment Share on other sites More sharing options...
91gtp Posted November 12, 2007 Author Report Share Posted November 12, 2007 i suppose either guess could be right. i am going to try to get a hold of the PO and see if he swapped the car over to a 5spd. I know he put a junkyard motor into it so i dont know what else was done. Quote Link to comment Share on other sites More sharing options...
5speedz34 Posted November 12, 2007 Report Share Posted November 12, 2007 i suppose either guess could be right. i am going to try to get a hold of the PO and see if he swapped the car over to a 5spd. I know he put a junkyard motor into it so i dont know what else was done. Check the RPO sticker on the spare tire cover. Look for the code "M27" that is the Getrag 284. If its printed on there the car is factory 5speed. Quote Link to comment Share on other sites More sharing options...
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