Powermaster Issue

[dand]

I know this topic has been discussed in many a threads on this site, but I just can't seem to figure out the problem based on the symptoms I am experiencing.
Whenever I step on the brakes normally the "brake" idiot light- blinks for a second, can hear the pressure switch make "clicking" noises and I have no stopping power (brake pedal feels soft), then I can feel the brake pedal get firmer and the brakes work fine then. If I brake hard, the light still blinks, and the pedal softness is much more noticable with increased pedal travel and no stopping power, then I can feel the pedal become firmer and have normal braking again.
I have read through many messages and diagnostic charts from this site as well as gnttype to no avail. It is a rebuilt unit from kirban about 4 years ago. I don't think it is the accumulator, since I don't have a harder than normal pedal feel ever.
I hope I have described the problem well enough and hope someone could enlighten me a bit further on these units. And of course any information is helpful and is very much appreciated.
Thanks

 

["Reaper"]

Sounds like it might be the brake proportioning valve.

1982-1984 1985 1986 1987 Buick Regal Grand National Turbo T T-Type GNX BRAKE PROPORTIONING VALVE #7189

 

[turbonut85]

Sounds like you have air in the accumulator/pump system. Pump the acc down (10-15 pumps ign off until the pedal is rock hard) and check the fluid. If it is "frothy" (little microbubbles) then let it sit for an hour or two so the bubbles will dissapate. Then, turn the ign on and see how it reacts. If it is not noticeably better, then cycle the acc at least 3 or 4 more times. If this doesn't work, you could have an internal leak in one of the o-rings in the master cylinder....:frown: that means rebuild....or better yet, Hydroboost conversion time. HTH ---Keith

 

[dand]

Sounds like you have air in the accumulator/pump system. Pump the acc down (10-15 pumps ign off until the pedal is rock hard) and check the fluid. If it is "frothy" (little microbubbles) then let it sit for an hour or two so the bubbles will dissapate. Then, turn the ign on and see how it reacts. If it is not noticeably better, then cycle the acc at least 3 or 4 more times. If this doesn't work, you could have an internal leak in one of the o-rings in the master cylinder....:frown: that means rebuild....or better yet, Hydroboost conversion time. HTH ---Keith

Just gave it a try now, pumped the pedal about 20 times, some pedal travel, but def. rock hard.
No air bubbles in the fluid
Thoughts?
worth checking out the proportioning valve as Reaper suggested?
Thanks

 

[turbonut85]

Did you turn the ign on and let the pump run til it shut off by itself ?? Geuss I left that out. If the car has been sitting, the pressure will bleed off, so you have to run the pump to build the pressure first, then turn the ign off and pump it down. Try that and post back what you find.

 

[dand]

Did you turn the ign on and let the pump run til it shut off by itself ?? Geuss I left that out. If the car has been sitting, the pressure will bleed off, so you have to run the pump to build the pressure first, then turn the ign off and pump it down. Try that and post back what you find.

Same results, No bubbles in the fluid
Thoughts?

 

[turbonut85]

Sounds like maybe an internal leak in the master cylinder. But before you pay the $$$ for another rebuilt one, it might be a good time to replace the proportioning valve, especially if you still have the original cast iron one. Try that first, then bleed the entire system. It is the cheaper alternative to a new PM, so it's worth a try first. If it turns out you need a new master cylinder, you should seriously consider doing the Hydroboost conversion. It is so much cheaper and isn't a ticking time bomb under your foot. ---Keith

 

[dand]

Thank you to everyone for your input
I called up Kirban and the powermaster unit is lifetime warranty, so i will send it to them to have it rebuilt, hopefully that will fix the problem.
So i guess i will be sticking with the PM, for now

 

[sniperdfa1]

Go vacuum!!

I had issues with the PM for the last 4-5 months, finally I went with the vacuum system that cost me $150 and it is AWSOME:biggrin:
It has some major stopping power.
The PM is discontinued, and the rebuilt ones are more trouble than there worth. They are expensive, hard to find and even though you have "lifetime"
warranty, it would take too much of your time taking it off, sending it out for repair, or new one, and replacing it, than driving and enjoying your GN.
In today's economy, who has $600-$1200, (yes $1200, check out ebay) to spend on this crap? Go vacuum and never have to worry about it again!

BTW;
There is a guy here in the website that said he totaled his GN because of a faulty PM. Would you take that chance?

Good Luck Brother.

 

[Roger]

My liffetime warranty pm has failed. Cardone & wagner & a third source do not have any available. Advance Auto Parts said minimum of 7 - 14 days & no promises.

 

[sniperdfa1]

That's where I bought mine, and when I took it back they couldn't even find me one, I'm in Chicago, and they called all they way to N.C. And they even told me the same, no promises. So much for my "Lifetime warranty"

 

[Little6pack]

i had issues with the pm for the last 4-5 months, finally i went with the vacuum system that cost me $150 and it is awsome:biggrin:
It has some major stopping power.
The pm is discontinued, and the rebuilt ones are more trouble than there worth. They are expensive, hard to find and even though you have "lifetime"
warranty, it would take too much of your time taking it off, sending it out for repair, or new one, and replacing it, than driving and enjoying your gn.
In today's economy, who has $600-$1200, (yes $1200, check out ebay) to spend on this crap? Go vacuum and never have to worry about it again!

Btw;
there is a guy here in the website that said he totaled his gn because of a faulty pm. Would you take that chance?

Good luck brother.

x2 go vac you will never go back

 

[turbonut85]

I still vote for Hydroboost. Best system (IMO) on a turbo car, period. (No flame intended, vac guys)

 

[highboost2000]

I agree with sniperdfa1, I got so tired of the PM setup I finally went and bought a dual diaphram with a master cylinder on it for $150.00, lowered the pin on my brake pedal and man oh man do I have brakes.
I only wish I would have done this YEARS ago.
Just my thoughts, and it only took half of a day, probably could have done it faster had I known what I was supposed to be looking for when taking everything apart.

 

[GNRick]

Thank you to everyone for your input
I called up Kirban and the powermaster unit is lifetime warranty, so i will send it to them to have it rebuilt, hopefully that will fix the problem.
So i guess i will be sticking with the PM, for now

Was Kirban able to replace it? Does Cardone have them in stock yet?

 

[dand]

Was Kirban able to replace it? Does Cardone have them in stock yet?

I haven't had the chance to take it off the car yet, because it is so cold outside
but i did call kirban up and they said they will send my unit out to cardone to have it rebuilt- looking at about 7-10 business day turnaround for the rebuild
i will keep you posted

 

[HUMBLE-U2]

x2 for turbonut85 hydroboost is the way to go believe me.went the vac setup. cheap yes. had to buy vac canister and turbo trans am billet vac block that go,s the brake booster.at this point it,s not cheap any more. but wait it gets better and more expensive i purchase a elec vac$250.00 pump .when that wasnt up to par. i called brian at gbodyparts got a used 85hydroboost w/ hoses for $125.00 now thats a cheap simple bolt on. the best mod for the buck. 1800psi line presure.the performance of the hb set up far excides the p.o.s pm or vac setup!