powermaster

[texasterror]

just bought an 87 GN all stock with 42K miles. Being that its stock how long will the powercrapper last for before it fails. i have heard that thing is not reliable. Also if i get a scanmaster for it does it no longer become stock?

 

["Turbo-T"]

How long the powermaster will last depends on how well it's been maintained over the years. Is the fluid nice and clear? Or does it have an amberish color like Coca-Cola? Clean fluid is vital to a powermaster's longevity. Also how firm is the pedal when pressed?

As for a Scanmaster, all that does is tap into the ALDL port under the dash and reads whatever the ECM is reading.It's a mod no less but it doesn't enhance performance so I'd still consider a stock GN with just a Scanmaster, a stock GN.

 

[texasterror]

the pedal is pretty firm and the liquid was not "white" clear but it was more of a light amber clear. I want to keep it stock but if its better to change it to a vacume or manual set up maybe I should do that. Any advice?

 

[357456]

Powermasters

My Buick's Powermaster made me a freakin specialist in rebuilds of them. I would keep the fluid perfectly clean. But they will still fail because because of the rubber in the accumulator breaks down with time from the fluid.

I then purchased a rebuilt unit with a life time warranty from the local auto parts chain. (it is really a Cardone rebuild) Just under $700. I have used the warranty twice so far with no drama. I get roughly about two years out of one of their builds. Best money I ever spent on one. GM has discontinued most of the parts associated with the units so this was my perceived only way out. And no, I don't want the vacuum booster set up. Not my thing. If you like yours great. I'll go vacuum when Cardone say they can't rebuild them anymore. (I still have enough new parts to build one more unit) I will say after all the time I have spent working on mine. "When Powermasters work, they work well."

I just helped a friend go back to a Powermaster set up from his used car's vacuum set up. We got a core from a Chevrolet wagon at the local junk yard.

IMHO I would not purchase a used unit for any money.... Well maybe for a core price. $75-100. Cardone I'm sure would like to have more units in the system. (I imagine) I'd ask them first before I bought one.

 

[Dennis Kirban]

Above postings are good advice....

One thing that has been overlooked is determine what version brake bowl (accumulator) is on the side of your powermaster brake unit.

Original version is all black with nut inward to attached it. They are prone to fail big time.

The second version bowl from GM the nut was on the outer edge of the surface and you can clearly read the yellow silk screening words on it. That version is better.

The third version was made by Cardone (we help push them to make it & also sell it)

This bowl is larger than stock and nut is inward. It has proven to be the most trouble free bowl of all.

The cleaner the fluid the better it is in your system.....most expensive foreign car manuals recommend changing brake fluid every 2 years or so....GM did not although they should have with these powermaster systems.

Dirty fluid and brake bowls is most of the issues. While others may disagree based on cars we have sold and we have sold a bunch...the more original it is the more demand or more buyers are interested. In other words I would keep the powermaster set up on your car. We sell the rebuilt ones with a lifetime warranty.

Also as much as a pain is if you got a car with a power antenna...wait til that fails....major job to replace and new ones are not available.....

denniskirban@yahoo.com

enjoy your new ride.......may any oil leaks be minor ones!

 

[turbo nasty]

That was my experience as well every 2-3 years...

Brake light would come on

PSI sw leaking or not working like it should.

Im pro vac brake swap others arent. I like my swap FWIW

 

[texasterror]

Thanks guys, i'll check it out this weekend. It's hard not driving the car but i guess im supposed to keep the miles low. Then again whats the point of owning a GN if you cant enjoy driving it. My power antenna has failed by the way but who cares i own a stock non molested turn key GN. Again thanks for the advice.

 

[turbo nasty]

FWIW the 89 TTA had a GN motor and vac brakes from the factory.

 

[Ross L]

I "passsed" on two GN's because the owner converted to vaccum. My powermaster made it twenty four years before it was replaced. The acc. ball and switch not so much.... Whens its working correctly it is a great system IMO. Never put off repairs if it starts acting up,,,, brake light, hard pedal ect. Quit driving and address issue.Good luck
Ross

 

[turbo nasty]

When the frequent break/fail parts for the PM didnt cost as much as a set of forged pistons it was ok LOL

 

[Roger]

84 & 85 GNs had the hydroboost.
I consider the hydroboost stock & it's way more reliable.

 

[Dennis Kirban]

84 & 85 GNs had the hydroboost.
I consider the hydroboost stock & it's way more reliable.

Some 1985s probably later VINS had the wonderful powermaster set up which we have found is the reservoir on those was actually narrower.

On a side note if you have a slanted reservoir it is one from another model car probably a stationwagon.

So, in review at least 3 different size reservoirs exist for powermaster units.

Alot of cores have passed through our hands over the years.

You would not think in looking back at various muscle cars over the years that so many problems would be associated with power brake systems....

denniskirban@yahoo.com

 

[Bweavy]

Thanks guys, i'll check it out this weekend. It's hard not driving the car but i guess im supposed to keep the miles low. Then again whats the point of owning a GN if you cant enjoy driving it. My power antenna has failed by the way but who cares i own a stock non molested turn key GN. Again thanks for the advice.

The best Answer I heard yet.

It's 42,000 not 4,200. Just check to see what if any re-calls have been done to your car. Brake proportioning valve should be brass. Brake switch should be gray. Dennis got you up to speed on the acc ball. Get the car safe & then play & enjoy it. If you remove something bag it & tag it with the date & mileage it was removed. A clean lower mileage stock car almost always brings more $ then a modified version with the same mileage.

 

[Dennis Kirban]

The best Answer I heard yet.

It's 42,000 not 4,200. Just check to see what if any re-calls have been done to your car. Brake proportioning valve should be brass. Brake switch should be gray. Dennis got you up to speed on the acc ball. Get the car safe & then play & enjoy it. If you remove something bag it & tag it with the date & mileage it was removed. A clean lower mileage stock car almost always brings more $ then a modified version with the same mileage.

Brian is correct....a little history on the proportioning valve GM used 3 suppliers..only one of which used brass other two material rusted....so from a math angle 1 out of 3 chances you got one of the "good" ones that is brass. Brian sells them as do us.

This information is from my one GM book from 1987.

denniskirban@yahoo.com

 

[GNRick]

People were discussing the recall on the prop. valve here a few years ago. Apparently it was recalled in Canada but not in the states. Some folks here said their dealer went ahead and replaced it for them with the brass unit. My Buick dealer wouldn't replace mine. I have a new brass one in a box waiting for my mechanic to replace it for me. The one on my 86 is rusted.

 

[texasterror]

No if and when this thing craps out on me is it gradual or am i going to be on the road and at 60mph its gonna fail. God i love driving this car its very very addicting.

 

[forzfed]

84 & 85 GNs had the hydroboost.
I consider the hydroboost stock & it's way more reliable.

My '85 had the power master and it went 2 days after I bought the car.

 

[Rich Gio]

No if and when this thing craps out on me is it gradual or am i going to be on the road and at 60mph its gonna fail. God i love driving this car its very very addicting.

Mine went gradually over the course of a few days. The brake light came on intermittantly on the way out to a show. Everytime I drove it the brake light came on longer. I ALMOST made it home when it failed. Damn, that was scary! I drove the last 10 miles at 15 mph on the back roads with a really hard pedal. Looking back, I really should have had it towed. If you see that light come on, I would address it right away! My issue was the Accumulator bowl, which I picked up from Mr Kirban. I purged the fluid and , knock on wood, it works great!

 

[bmackinnon]

No if and when this thing craps out on me is it gradual or am i going to be on the road and at 60mph its gonna fail. God i love driving this car its very very addicting.

That's the biggest problem with the PM.... it CAN crap out on you completely unexpectedly, with zero warning....(as but one example, if the fuse pops)... in that case, the damn brake idiot light won't even light up...UNTIL.... you've braked a couple of times to use up the reserve pressure in the accumulator ball, and the next time you hit the brakes, they are ROCK hard (ie. no assist). Then the light comes on.... thanks... This caused the previous owner of my car to spear a telephone pole at about 20 mph as he tried to stop at "T" intersection. Incidentally, this is what caused him to sell me the car...

FWIW, when the PM does fail, you DO still have brakes, but they require you to nearly break the seatback from the force you have to exert on the pedal.... more so than a typical vac system with no vacuum.

I also hated the ridiculous sensitivity/lack of modulation of the PM system. Since I converted to vac 12+ years ago, never had a single brake problem and the worry never enters my head.... brakes feel just like any other 80's GM car with vac brakes. I love my vac brakes and wouldn't have them any other way....

 

[turbolou]

reply

Above postings are good advice....

One thing that has been overlooked is determine what version brake bowl (accumulator) is on the side of your powermaster brake unit.

Original version is all black with nut inward to attached it. They are prone to fail big time.

The second version bowl from GM the nut was on the outer edge of the surface and you can clearly read the yellow silk screening words on it. That version is better.

The third version was made by Cardone (we help push them to make it & also sell it)

This bowl is larger than stock and nut is inward. It has proven to be the most trouble free bowl of all.

The cleaner the fluid the better it is in your system.....most expensive foreign car manuals recommend changing brake fluid every 2 years or so....GM did not although they should have with these powermaster systems.

Dirty fluid and brake bowls is most of the issues. While others may disagree based on cars we have sold and we have sold a bunch...the more original it is the more demand or more buyers are interested. In other words I would keep the powermaster set up on your car. We sell the rebuilt ones with a lifetime warranty.

Also as much as a pain is if you got a car with a power antenna...wait til that fails....major job to replace and new ones are not available.....

denniskirban@yahoo.com

enjoy your new ride.......may any oil leaks be minor ones!

Dennis years ago when the proportional valves were still available you would recommend changing them also. I have had my share of spongy pedal complaints linked to a bad valve & hardly hear any mention of that possibility when trying to diagnose power master problems.