Powermaster Issues

RezVek

Member
Joined
Jul 27, 2021
First time poster here. Let me start by saying I am in the middle of Canada so my resources for a local knowledge base are very limited, even more limited when dealing with a PM. I am NOT a mechanic and the closest thing i was to a mechanic before owning my 87GN is that i bought some tools. I feel i have learned a lot from forums like this as I have been reading them for a couple years since I first got my GN and it has always been a great source of info!

Right now, I am having an issue with my PM brakes and can’t find a related issue. Please note that during this whole ordeal, the brake light never comes on(but it does work when i apply the emergency brake), which is making this hard to follow troubleshooting procedures as most reference “is the light on?”. The other day I was getting ready for a show and moving vehicles around and my GN had a hard pedal. I got my cars moved around and checked the PM, it had some oily moisture on the top of the reservoir cover and in the plug socket at the top (pressure switch?). I cleaned that all up and once I was ready, I headed to the show and part way there, hard pedal almost no brakes. I came to a stop and checked the PM, pulling the connector at the top off(pressure switch?) and resat it, got back in and brakes seemed ok. Decided to head home and the brakes were fine for the 10-15 min drive so I turned back around and headed back to go to the show, no problems. After the show, I was nervous for the drive home, but no issue.

Last year I did “clean” the fluid by a method I found on Youtube where I would pump the brake 10-12 times, drain and refill the fluid, pump, drain/refill, and repeated till the full reservoir fluid was clear. This all worked fine then (last spring) and no issues all last year, even for a couple drives this year.

Now, key off, the pedal is hard immediately when I did the 10-12 pumps and checked the reservoir and it was not even half full(keep in mind that other than the bit of fluid I found, there is no evidence that half the fluid escaped. I topped the fluid in the reservoir and went key on. The PM cycled for 2-3 secs and stopped, leaving the reservoir about half full. Did this a few times, not adding more fluid as there is likely too much already, with same results. At this point it seems something “non electronical” leading me to think the accumulator is holding fluid. But i thought i would test the switch at the top of the PM as per a guide I found and I had no continuity between any of the 3 pins. So, I do know some GN guys and most cars have been converted to vacuum or hydra. I borrowed a switch and it had continuity so I swapped it out, same issue. My switch now bench tests fine and his no longer has continuity in the car. I pulled it and it tested fine again, so I put mine back in. Of course , same issue.

I tested the brakes in the driveway and they are 100% fine. I have working brakes that don’t seem softer or harder than usual with engine running, but I know there is an issue. I am not overly comfortable driving it, knowing they could fail at anytime.

I could get a switch and ball to the tune of about 450-500 (USD, much more in my crappy Canadian dollar!). But I don’t even know what the issue is! I hate to just throw money at it, not knowing the root cause. Do I cut my losses and just convert to vac? hydra? I don’t race but want it to perform. Any Canadian sites sell these units(vac or hydra)?

Any and all help is welcomed!
 
If the pump / motor assembly is in good condition and working well then you have the most important part. A seal kit from RCG along with a new hydac accumulator and a new switch and you can build yourself a good unit. Take care of it by depressurizing when parked and clean fluid every year and it will last a long long time.
That being said, vacuum is a perfectly good way to go too.
 

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Thanks for the replies. I checked RCG but couldn’t see any kit there and that manual will come in handy. I had seen that flowchart before but my issue does not have a brake light so according to the chart, system OK. But system not Ok lol…. it is so odd that the brakes work, but accumulator will not release a proper fluid amount back to the reservoir.
 
When you drain the accumulator and the level is where it should be, when you turn the key on it
should take about 15 seconds to fill the ball back up and shut off. I wonder if perhaps your pump is weak.
But you need special tools to really find out.
When fluid disappears, sometimes the seal between the motor and pump is bad and it can drain into
the motor. Does your motor ever feel hot?
If it's never been rebuilt in all these years and you want to keep it, send it off to the boss man of PMs, Richard Clark
and he will fix it right.
I personally like the PM and it served well for 180,000 miles before the motor finally gave out. RC rewired the motor and check
all the specs and it has been good to go for 4 years. It is on its 4 accumulator though.
The biggest thing is to always change the fluid at least once a year.
If I were to change to hydro or vac I'd go with the vacuum, why put all that extra stress on your old power steering pump
and have more places for a leak.
Keep us posted.
 
When you drain the accumulator and the level is where it should be, when you turn the key on it
should take about 15 seconds to fill the ball back up and shut off. I wonder if perhaps your pump is weak.
But you need special tools to really find out.
When fluid disappears, sometimes the seal between the motor and pump is bad and it can drain into
the motor. Does your motor ever feel hot?
If it's never been rebuilt in all these years and you want to keep it, send it off to the boss man of PMs, Richard Clark
and he will fix it right.
I personally like the PM and it served well for 180,000 miles before the motor finally gave out. RC rewired the motor and check
all the specs and it has been good to go for 4 years. It is on its 4 accumulator though.
The biggest thing is to always change the fluid at least once a year.
If I were to change to hydro or vac I'd go with the vacuum, why put all that extra stress on your old power steering pump
and have more places for a leak.
Keep us posted.
Not sure about the hot motor but the sound is dead on where is makes the regular pump noise then you hear it start making lower “close to cut off” sound, then stops. All sounds very normal just the duration is off.
 
you’ll have to call RCG for the seal kit if you want one. If you keep the powermaster even if you don’t rebuild it today you’ll probably want to have the seal kit on hand for later on down the road.
 
An occasional "hard pedal" is the rehearsal to putting the car up someone's tailpipe.
Stop driving it until you make the repairs.
Yes I have done that. The only driving it’s getting is moving from one side of the garage to the other. Soon it will be resting till repaired. It is just a baffling case. I am looking in to a vacuum conversion, full kit with pedal as I don’t want to have to modify a pedal…..if anyone has any suggestions. iI have seen a few vendors including Kirbans and GBody.
 
Mine did what you're describing and I chased it for a while. Lost all brakes when moving it in the driveway but was able to stop before I rolled into the garage door. Switched to hydroboost and it's worked great.

You can get a vacuum conversion kit from GBody (I think) then put up a Parts Wanted ad here to see if anyone is selling a pre-modified pedal. Based on what I've been reading on the board it sounds like Kirban isn't owned by Dennis anymore, and the new ownership has a track record of poor performance.
 
Mine did what you're describing and I chased it for a while. Lost all brakes when moving it in the driveway but was able to stop before I rolled into the garage door. Switched to hydroboost and it's worked great.

You can get a vacuum conversion kit from GBody (I think) then put up a Parts Wanted ad here to see if anyone is selling a pre-modified pedal. Based on what I've been reading on the board it sounds like Kirban isn't owned by Dennis anymore, and the new ownership has a track record of poor performance.
Thanks for the input about Kirbans. I will keep looking for an alternative. How long ago did U switch? Where did you buy from and what was the price? (if you don’t mind me asking)
 
I switched around 2012. Don't remember where I got each component off-hand, sorry.
 
Remember, if you switch to vacuum and buy the booster and master cylinder as a unit and one of
them go bad (booster or master), the parts store will most likely want the whole unit back to replace the bad part. And you don't
want to go under the dash twice fighting that pedal.
Earl has had the bestest reputation for years though so I wouldn't hesitate buying from him.
 
Thanks everyone. Looks like Earl is the one I should go with. I sent him a message as it seems his system repurposes the existing pedal, but i’m nervous to modify it. Looking for clarification on that from him, unless someone here knows?
 
Thanks everyone. Looks like Earl is the one I should go with. I sent him a message as it seems his system repurposes the existing pedal, but i’m nervous to modify it. Looking for clarification on that from him, unless someone here knows?
Modifying your existing pedal is no big deal, just need a drill, the right size drill bits, and a small sledge hammer (I used a regular hammer, just took more whacks to set the pin). The biggest pain in the whole swap is getting under the dash to get to the pedal. By modifying your existing pedal if you ever decide to go back to the PM you won't have to take the pedal out again. If you take your seat out its a little easier to get to the pedal especially if you are on the larger side.

Even though we lost all the photos this link should help better understand the procedure Vacuum Brake Conversion
 
Changing the pedal wasn't that bad. Just drop the whole bracket down replace the pedal and stick it back in. I did it on my knees with my 60/40 bench just moved back all the way.
 
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