Unique powermaster brake issue (please read it. It’s not the usual powermaster failure symptoms)

87WE4!!

Active Member
Ok, I read just about everything I could find on powermaster brake boosters. But I don’t think it’s my powermaster.
Let me start by saying in the 31 years of owning my we4 I managed to keep my eyes open and I purchased 4 known working 3 or them I witnessed working with my own foot. 2 guys converted to vacuum brakes (Which I’ve always been strongly against doing, it’s just my preference to keep all my TRs powermaster). 1 guy was parting a rotted GN out and I bought it from him. And one I recently purchased on eBay for a steal and the seller is a know TR parts seller and guarantees it’s functional. When I get each unit I look it over for cracks or leaks. Then I ohm out the motor and brake switch. Then I gravity bleed the motor and leave a little bit if new fluid in the left side of the reservoir, cover it up, wrap it real good in plastic shrink wrap and store then on a shelf in my closet.
So my WE4 was stored in my sister’s garage in carle place NY from 1997-2018 because my mom was a big help in me buying this car 3 days after my 17th birthday right off the dealer lot. When she passed away unexpectedly back in 1997 I was too emotional and hurt to even look at the car because before she lent me the cash to buy the car I was very disrespectful to her and said shit I can’t ever take back. So I was too crushed to even look at the car. So my sister let me Store it in her garage for 21+ years until she retired and sold her house this year. When i Parked it there all I did was remove the battery and give it to my sister for other card to use. I never prepare the car for long storage. So she shipped it to me here in Florida. About two months ago when I got an FL completely different about it and have been breaking my neck to restore back to a museum quality show car. One of the problems was a very stiff pedal. No brake light (now here’s where it gets tricky). No oil light upon ignition, no volts light, no change from the alternator either. Now I know the volts dash lamp completes the charging circuit. So tomorrow I plan to remove the dash cluster and check all the lamps as well as the coooer connection that powers up the entire dashboard.
Ok back to my original powermaster. Upon removing it I noticed that the pedal was stiff because of the years of sitting with dirty brake fluid inside the master cylinder and some was leaking out the seal where the hole for the pedal pushrod sits and was all hard like dried epoxy. The resistance on the powermaster motor and brake switch all checked out good. So I replaced it with a known good one with a fairly new accumulator ball that was replaced approximately five months before the car was parated out. Ok so here are my issues. Now I know you guys know a hell of a lot more then I know about our cars so I come to y’all again asking for your help please. This powermaster is definitely a known working unit. But I cannot get her to function. I installed it perfectly. I gravity blead the motor and Accumulator ball side. The brakes slightly work if I press as hard as I can.

Here is what I got so far:’

1) no red brake lamp on the dashboard no matter how much I troubleshoot the brake switch pigtsil harness. I can’t get it to light up.
2) absolutely no power/voltage from the brake switch pig tail harness and it’s very clean.
3) standing 12 volts in one of the wires in the pig tail harness that’s going into the powermaster motor connection.
4) I read something about the emergency /parking break being released having something to do with the brake lamp red right. How can I bypass the switch? It’s kinda seized because it sat so long

5) Probably a relevant to my problem with the power master but I’m going to mention it anyway Oil idiot red lamp not lighting up. Please lmk if this has anything to do with the powermaster. Same with the red volts dash lamp. That bulb has to be replaced because my car isn’t charging because of that.

So the bottom line is since I started with my car again I haven’t hesrd the powermaster motor prime itself at all. Honestly guys /ladies I feel it’s not the powermaster and has something to do with the no red brake lamp on the dashboard. And the fact that there is no power coming from any of the 3 wires that connect to the brake pressure switch.

****I HAVE NEVER HEARD ANY POWERMASTER MOTOR OR RELAY SINCE I GOT MY CAR BACK****
I removed that one big metal fuse and temporarily replaced it with a 30 AMP plastic fuse with no change. Are there any other fuses to check? Is there an emergency brake switch that’s causing some kind of interference with this power master issue ? Also my brake pedal is sticking from age and it kept the rear brake lights on, so I disconnected two sets of wires coming from there. Could that have caused this problem? Other then that honestly guys I’m stumped. All I can say is I swear by these powermaster units. Especially the one I just installed. Oh and yes the grounding wire that goes into the harness on the side of the powermaster is connected to the chassis ground with a clean great connection. I read about thst in one of theses thread about failing powermaster units.

Thank You all for reading and have a blessed day

Any answers or input to any of the questions would be greatly appreciated !!!
 
Anyone anyone??? I know it’s not the powermaster. I need brakes!!! Is the brake dashboard lamp like the volts dashboard lamp? $h!t stops working if that light burns out? Because my whole instrument panel back ribbon is jacked up. I have no idea why. The car slept in my sisters garage for 21+ years. Why are all these wires all brittle and corroded in the dash compartment. Car was in a enclosed garage under a car cover. I’m like wtf?
 
Where are you located? If anywhere near NC you should get to Richards. He is the power master expert fo sure.


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OK I admit I did not read your whole dissertation about the brakes because I knew I could not be helpful anyway but now I see you are not near NC. Sorry and good luck!


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OK I admit I did not read your whole dissertation about the brakes because I knew I could not be helpful anyway but now I see you are not near NC. Sorry and good luck!


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Thank you anyway for your help. Just responding is helping me. Is it just that one fuse or is there another fuse. I have standing voltage at the pump in one of the wires going to the powermaster pump.
 
3 fuses, GAGES fuse for the lamp, needs to work for the brake lamp light circuit you will be testing, hot in run, bulb test, or start. 20A.

RLYS fuse for the powermaster brake relay coil contacts that run the motor. 5A

PWR BRK fuse that feeds the brake relay main contact to run the high current motor. 30A.
 
3 fuses, GAGES fuse for the lamp, needs to work for the brake lamp light circuit you will be testing, hot in run, bulb test, or start. 20A.

RLYS fuse for the powermaster brake relay coil contacts that run the motor. 5A

PWR BRK fuse that feeds the brake relay main contact to run the high current motor. 30A.
Thank you. I’ll definitely check it out in the morning. I appreciate your help!!!!
 
The Powermaster is just like us humans, it IS going to die in it's short life, and just hope it is not when you need it in an emergency stop!

My opinion is to go with vacuum brakes, and if the GN ever becomes a "garage queen", it is simple to re-install the PM.
 
The Powermaster is just like us humans, it IS going to die in it's short life, and just hope it is not when you need it in an emergency stop!

My opinion is to go with vacuum brakes, and if the GN ever becomes a "garage queen", it is simple to re-install the PM.
I agree 100% with what you’re saying. As soon as the powermaster goes on my other GN I’m going to hydroboost brakes.
But I’m the original owner of my WE4 (my other TR) and I still have every single document that ever came with my car. This was my very first car and it has a lot of sentimental value and memories. So this will be a garage Queen. I had her in storage for 21 years because of personal reasons. But anyway I’m fixing my WE4 up to be a museum quality show car. And I want it to be all stock with the exception of the mandatory Alky kit, gauges, and scanmaster. I was even lucky enough to find 4 original TR Goodyear Eagle GT 215/65R15s tires dated the 4th week of 1987 that we’re kept in climate controlled storage. I plan to use these and enter my car into car shows (I would never drive on those 31 year old tires. They are for shows only). So I really need my powermaster. I want literally everything to match my RPO codes. But I don’t plan to drive my WE4 more then one day a week and just around the area. I have another TR to have fun and drive.
But this problem isn’t the powermaster. This is a known working powermaster unit. I’ve been having issues behind my dashboard and behind my instrument panel since I took it out of its 21 year storage. Everything was working fine when I parked it in my sister’s garage back in 1997. Idk how it got do messed up. Nobody touched it. I even removed the battery and gave it to my sister. But I agree that the powermaster is a living thing and can either have a lingering death or a sudden death. All I can do is pray it never dies while I’m driving. I’ve always been very anal when it comes to changing the brake fluid in my GN and always gravity bleed it and never let the reservoir run dry. I keep flushing it with new fluid till it turns clear.
 
I found the issue. Thanks to the Wiring schematic that one of y’all posted. Turns out the 30 amp fuse is good and I have standing voltage at the fuse box but somewhere along the way the red 12v standing voltage wire got pinched or broken because I have no voltage at terminal C. But I do have ignition voltage at terminal B. So I jumped terminal C with a paper clip tip that I mounted to a wire and attached it to the positive terminal and as soon as I turned the key into ignition I had power brakes again. As far as the brake dashboard lamp goes I’m waiting on the rear instrument cluster ribbon so the gauges and lights aren’t even installed.
But thanks to everyone for your help.
 
I found the issue. Thanks to the Wiring schematic that one of y’all posted. Turns out the 30 amp fuse is good and I have standing voltage at the fuse box but somewhere along the way the red 12v standing voltage wire got pinched or broken because I have no voltage at terminal C. But I do have ignition voltage at terminal B. So I jumped terminal C with a paper clip tip that I mounted to a wire and attached it to the positive terminal and as soon as I turned the key into ignition I had power brakes again. As far as the brake dashboard lamp goes I’m waiting on the rear instrument cluster ribbon so the gauges and lights aren’t even installed.
But thanks to everyone for your help.
I know this is a really old thread, but has mouse hotel written all over it. Did you ever find the smoking gun?
 
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