another powermaster brake question

[Cootza]

I had my powermaster unit replaced and it has less than 1000 miles on it, the car sat in storage for most of this time. Now that I have it running daily, my brake light comes on after I depressurize the brakes. the black motor beneath the PM will run and make a hiss sound that sounds like crap, it will not stop, runs continuosly!?!?
I have the grey pressure swith. At one point recently, the resivoir lid poped off and brake fluid every where. Is my motor unit bad?

 

[gteatr6]

My guess would be the accumulator is bad. Usually the fuse blows when the motor is bad.

 

[Cootza]

I'll check the fuse. Thank You.

 

[gteatr6]

The fuse only blows when the motor is bad, ie the motor doesn't work.
Do a search for how to test a powermaster and ohm out the gray switch. The switch can make the motor run constant also.

 

[chopped39]

Take the power master off and put it in the box the vacuum booster or hydoboost you buy comes in.:biggrin: Take that crap off your car. The light coming on is at least a warning. Mine gave me no warning when it failed at 45mph as some meatstick pulled a u turn in front of me. I know you spent a lot of cash on power master but it is a crap system. good luck either way you go

 

[Cootza]

I hope it is just the switch, due to high cost of all other parts.

 

[Cootza]

conversion is sounding good right now, but trying to keep all original. comes down to dollars and sense I guess...

 

[chopped39]

For what you will pay for the ball and switch you can have a vacuum set up and get rid of your problems. Dont get rid of the power master. I kept every original part from my car just in case.

 

[turbo nasty]

Hexk for what he pays for a ball and switch he could do the swap and still have cash left over

 

[1quick6]

To definitely say it is the motor, you need to pressure test the system. If the pressure never reaches 540psi or so, the motor will never shut off. The normal operating range where the pump will not run is 540-770psi. If the pressure EXCEEDS 770psi, the brake pressure switch is bad. That tells the pump when to turn on and off based on what it sees for pressures.

If you aren't reaching the 540psi shutoff, look in the passenger side of the reservior. If you don't see anything happening, the motor/pump isn't producing enough pressure.

Based on your description, it sure sounds like your motor isn't able to produce enough. Typically, if it is the accumulator the pump won't run all of the time ... just more often since it has to recharge a leaking ball. In a regularly operating PM, the motor only kicks in once every 3-4 brake applications when the pressure switch sees the pressure drop below 540psi.

That's the bad thing about repairing PM systems. Every piece is expensive and as soon as you fix something, something else becomes a potential expensive point of failure. Most people decide to throw in the towel and go with more dependable and simpler systems like vacuum or hydroboost. If it were me, I'd seriously consider a conversion to either system. I am not anti-PM, but this is an opportunity to improve the safety of your car.

 

[zeus87gn]

Take the power master off and put it in the box the vacuum booster or hydoboost you buy comes in.:biggrin: Take that crap off your car. The light coming on is at least a warning. Mine gave me no warning when it failed at 45mph as some meatstick pulled a u turn in front of me. I know you spent a lot of cash on power master but it is a crap system. good luck either way you go

Hater

 

[zeus87gn]

I had my powermaster unit replaced and it has less than 1000 miles on it, the car sat in storage for most of this time. Now that I have it running daily, my brake light comes on after I depressurize the brakes. the black motor beneath the PM will run and make a hiss sound that sounds like crap, it will not stop, runs continuosly!?!?
I have the grey pressure swith. At one point recently, the resivoir lid poped off and brake fluid every where. Is my motor unit bad?

More than likely it has entrapped air.
Did you leave it sit while pressurized? Bad move if so.
If the cover blew off, it's over full.
You need to cycle the accumulator and get the air out.
Read my procedure for cycling - link in my sig.

 

[kaj]

what's involved in swapping to a conventional vacuum set up?

 

[turbojay]

what's involved in swapping to a conventional vacuum set up?

Replace Powermaster unit and pedal with Booster, Master Cylinder, & Pedal from regular 1987 Regal V8 and bleed the brakes. Also will need a vacuum block with extra port.

I just got this done on my car today and the vacuum brakes feel much, much better. I was also getting the brake light and the motor was making weird sounds, I was always nervous driving the car that way. I wimped out and had a mechanic do it and the labor was $200 plus $150 for the parts for total of $350. Not too bad and now I can drive the car with confidence that the brakes will work.

 

[kaj]

Replace Powermaster unit and pedal with Booster, Master Cylinder, & Pedal from regular 1987 Regal V8 and bleed the brakes. Also will need a vacuum block with extra port.

I just got this done on my car today and the vacuum brakes feel much, much better. I was also getting the brake light and the motor was making weird sounds, I was always nervous driving the car that way. I wimped out and had a mechanic do it and the labor was $200 plus $150 for the parts for total of $350. Not too bad and now I can drive the car with confidence that the brakes will work.

wow. where did you find the parts?! i have found complete used and new kits for $225/$395 respectively. $150 for parts would be awesome. i plan to convert to vacuum. definitely.

 

[1quick6]

You can watch the for sale section on this site too. There are always boneyard vacuum kits with pedal for sale.

I did my hydroboost for about $300 with reman parts. Vacuum is definitely an easier install ... I just prefer the pedal feel and clamping power of hydroboost systems.

 

[kaj]

You can watch the for sale section on this site too. There are always boneyard vacuum kits with pedal for sale.

I did my hydroboost for about $300 with reman parts. Vacuum is definitely an easier install ... I just prefer the pedal feel and clamping power of hydroboost systems.

i'm familiar with vacuum and i guess change is hard. LOL. hydroboost sounds excellent.. just not sure i want to deal with the added cost and complications of an unfamiliar system.
plus.. i can't find anywhere to do hydroboost for $300. i looked, though i'll admit i'm not the best searcher/googler.

i'll keep an eye out. i believe a member here has the complete vacuum setup available for about $100. that's though to beat.

 

[1quick6]

I'd say go with the vacuum setup since you are comfortable with it. I wasn't comfortable with hydroboost at first either, but after driving a car with it I was sold. Turbonut85 had put together a great list of parts you can piece together for cheap, but you can also buy new kits that are ready to go, although they are pricey. I didn't have any unexpected problems aside from normal things that happen when working on things that hadn't been touched in 20+ years ... i.e. rounded off bleeders and brake line fittings.

Good luck.

 

[jdpolzin]

If you guys are looking for a Hydroboost set up, I just pulled one off my low mile car because it's going back to stock. The booster is a reman that works, one line is brand new (still in the wrapper, never used) and the other is one that was made at a hydraulic shop (this is the tricky one that goes to the pump). I have brand new in the box master for it too. SO basically a brand new set up for $300. -----Jeremy

 

[turbojay]

wow. where did you find the parts?! i have found complete used and new kits for $225/$395 respectively. $150 for parts would be awesome. i plan to convert to vacuum. definitely.

I bought a complete kit from a guy on this board, I forgot his name. Keep an eye on the "For Sale" section. The kit included everything I needed, pedal, booster, master cylinder, filter, & hose. You can probably save more money if you buy all the parts from the junkyard or autoparts store. You can find the part #s on rockauto.com, look for a V8 1987 Regal.