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My GN almost killed me the other day! 
Was out cruising & the brakes died. GNs have a very weird electric-over-hydraulic brake system that was never used in any other vehicle. It's called the Powermaster brake system. GM used it for the last 3 years of turbo Regals as a technology experiment, but dropped it after that because it was noted to be problematic & sometimes even dangerous. Anyway...it's powered by a fucking insane 1800 PSI hydraulic system that's driven by a hydraulic pump that pulls 40+ amps & has a motor that's about the size of a motorcycle starter! Unlike regular vacuum power brakes, where you still have halfway decent manual brakes when the vacuum quits - when this system fucks up, you have essentially no brakes at all. The pedal either goes to the floor, or gets absolutely-rock-hard like you're pushing on a fixed object.
Two days ago, it died in rush-hour traffic @ highway speed on Hwy 77, just north of the 494 exits. Big traffic-jam! No time to use the emergency brake. Had both feet on the brake pedal, pushing as hard as I could possibly do, while pulling on the steering-wheel with both hands for leverage as I as hard as I was physically capable of doing, while nearly breaking the driver's seat off it's mounts! No real braking force at all. Didn't have time to reach over & pull the emergency brake lever with my left hand & then put my left foot on the pedal to use it as a regular brake. Had to pull the gears down hard, nearly redlining the engine with each downshift to get enough engine braking force do any good. Was gonna drive it into the fucking fence/wall/barrier to avoid hitting the stopped traffic ahead, but I managed to get it down to ~10 MPH on engine braking & then managed to get it stopped, about 3 ft from the car ahead of me. HOLY SHITFUCK!!!!!!!!
Got off the highway ASAP & drove the 60 blocks back home on city side-streets @ 5-10 MPH in 1st gear, to avoid any other issues.
I had the system fail @ 175k miles, but that time the pedal went almost to the floor & I still had at least a suggestion of brakes. I bought an entire new factory GM Powermaster brake system for it then. But this time it died in less than 25k miles! The system is noted for having really high braking force, but it's also for being dangerous when it fails. The brake warning light on the dash is called "the red light of death" by the turbo Buick community.
Anyway...I'll never trust a GM Powermaster braking system again, after nearly getting killed by it twice. Gonna do a whole braking system conversion to regular vacuum power brakes. A number of the national & local GN cub members converted theirs years ago. Gotta change everything but the brake lines & brake cylinders. Even have to remove the brake pedal assembly & replace it with one from a regular G-body car that came with a naturally-aspirated gas engine & vacuum brakes. The other option is to convert to the Hydroboost brake system that's powered by the power-steering pump, which GM has used on a number of vehicles. That's a great braking system with gobs of braking force, but converting my GN to Hydroboost costs nearly $3500 just for the kit & then I'd still have to get it all installed. So...I'm gonna do the vacuum conversion.
Holy shit, what an experience!! So, now I have to spend around $1k+ on the vacuum brake conversion, plus I still need to get the turbo & downpipe replaced this season.
Was out cruising & the brakes died. GNs have a very weird electric-over-hydraulic brake system that was never used in any other vehicle. It's called the Powermaster brake system. GM used it for the last 3 years of turbo Regals as a technology experiment, but dropped it after that because it was noted to be problematic & sometimes even dangerous. Anyway...it's powered by a fucking insane 1800 PSI hydraulic system that's driven by a hydraulic pump that pulls 40+ amps & has a motor that's about the size of a motorcycle starter! Unlike regular vacuum power brakes, where you still have halfway decent manual brakes when the vacuum quits - when this system fucks up, you have essentially no brakes at all. The pedal either goes to the floor, or gets absolutely-rock-hard like you're pushing on a fixed object.
Two days ago, it died in rush-hour traffic @ highway speed on Hwy 77, just north of the 494 exits. Big traffic-jam! No time to use the emergency brake. Had both feet on the brake pedal, pushing as hard as I could possibly do, while pulling on the steering-wheel with both hands for leverage as I as hard as I was physically capable of doing, while nearly breaking the driver's seat off it's mounts! No real braking force at all. Didn't have time to reach over & pull the emergency brake lever with my left hand & then put my left foot on the pedal to use it as a regular brake. Had to pull the gears down hard, nearly redlining the engine with each downshift to get enough engine braking force do any good. Was gonna drive it into the fucking fence/wall/barrier to avoid hitting the stopped traffic ahead, but I managed to get it down to ~10 MPH on engine braking & then managed to get it stopped, about 3 ft from the car ahead of me. HOLY SHITFUCK!!!!!!!!
Got off the highway ASAP & drove the 60 blocks back home on city side-streets @ 5-10 MPH in 1st gear, to avoid any other issues.
I had the system fail @ 175k miles, but that time the pedal went almost to the floor & I still had at least a suggestion of brakes. I bought an entire new factory GM Powermaster brake system for it then. But this time it died in less than 25k miles! The system is noted for having really high braking force, but it's also for being dangerous when it fails. The brake warning light on the dash is called "the red light of death" by the turbo Buick community.
Anyway...I'll never trust a GM Powermaster braking system again, after nearly getting killed by it twice. Gonna do a whole braking system conversion to regular vacuum power brakes. A number of the national & local GN cub members converted theirs years ago. Gotta change everything but the brake lines & brake cylinders. Even have to remove the brake pedal assembly & replace it with one from a regular G-body car that came with a naturally-aspirated gas engine & vacuum brakes. The other option is to convert to the Hydroboost brake system that's powered by the power-steering pump, which GM has used on a number of vehicles. That's a great braking system with gobs of braking force, but converting my GN to Hydroboost costs nearly $3500 just for the kit & then I'd still have to get it all installed. So...I'm gonna do the vacuum conversion.
Holy shit, what an experience!! So, now I have to spend around $1k+ on the vacuum brake conversion, plus I still need to get the turbo & downpipe replaced this season.
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