Hard brake pedal when hit fast
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chopped39
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- Aug 30, 2004
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Thats what mine did when I wrecked my car. Guy through a u turn in front of me and I slammed on the brakes and it was a rock hard pedal. The lumina stopped me pretty good though. I never had any problems before that
I know the conversion is somewhat of a pain but I highly recommend it. I was a stubborn fool for 2+ yrs trying to make the PM work. Waste of time and money, not to mention the safety aspect.....which I'm embarrassed about.
Just bite the bullet and swap to vac or hydro, you'll be glad you did.
Thanks man
What did you you do chopped39 to resolve the problem? Conversion?
I just swapped to the vacuum, purists will not be happy and I get that, but with a little one and horror stories I read I swapped. I swapped for less than the cost of an accumulator ball and I did with new / remaned parts. Got my brake pedal from a cutlas at the bone yard. Here's where I got the booster / master:
http://www.autozone.com/autozone/pa...izcdZ8kn7z?itemIdentifier=729319_131640_8550_
there are guys who sell the kit.
A good question on the powermaster is, how is it that they go bad so fast without a warning light first? Is it that the accumulator ball goes bad suddenly? Even with a bad ball if the pump is working you should have brakes right? Mine worked just pump ran almost all the time, the brakes were soft in my case.
there are some great posts on step by step on the swap.
Joel
http://www.autozone.com/autozone/pa...izcdZ8kn7z?itemIdentifier=729319_131640_8550_
there are guys who sell the kit.
A good question on the powermaster is, how is it that they go bad so fast without a warning light first? Is it that the accumulator ball goes bad suddenly? Even with a bad ball if the pump is working you should have brakes right? Mine worked just pump ran almost all the time, the brakes were soft in my case.
there are some great posts on step by step on the swap.
Joel
Some one should sell a plug and play Hydroboost, The units from the Astro van are plentiful in the junk yards but the firewall bracket is kind of a stumbling block. I could get them made but the machine shop wants $1000 in start up costs. My Hydratech unit works good but it was $500.
They do fail slowly. When the hydraulic accumulator is 'perfect' it stores around 12 pumps of the pedal without cycling the motor. As the pressure leaks out it stores less and less energy. When it gets down to one pump tripping the pressure switch that's when you start seeing the light and feeling the motor pulling the brake pedal down as it's being actuated.
chopped39
Well-Known Member
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- Aug 30, 2004
- Messages
- 4,269
The car is going through a frame off as we speak. I'm putting vacuum on it for now and may go hydro boost down the road.
The hydro boost will hold a lot better from what I was told but the vacuum is cheap
Actually it only stores 2-3 pumps of the pedal. I knew mine was failing when the motor ran on every pump. Then I smelled smoke and got one pump. Sent it back to Cardone, got a rebuilt unit and sold it at a swap meet.
He's talking about one pump turning the light on. It should take several pumps to turn the light on. The light comes on when the pressure is extremely low. If the light comes on with one pump,you know the accumulator isn't storing much because the pressure is dropping a great amount with that one pump.
Curious how guys lose all braking with little if no warning?? My car was running the pump about 20 seconds per press of the pedal but no light. Scary that you can lose brakes with no warning.
One would think that in practice a warning would occur if the ball was failing even a little bit, but sounds like that is not the case?
Joel
One would think that in practice a warning would occur if the ball was failing even a little bit, but sounds like that is not the case?
Joel
turbo87regal
Member
- Joined
- Nov 12, 2005
- Messages
- 356
Get rid of that press and pray powermaster. Like stated above unless your a purist and need the car to look 100% stock there is really no reason to keep that powermaster and hope it works when you need it. Vacuum brakes work great (89 TTA came with that from factory) and its cheap to swap. Hydroboost gives out more pressure but is more expensive and not the prettiest thing to look at if you ask me.
The problem is that people don't understand how the Powermaster functions. It's important to test it periodically by depressing the brake pedal 10 times without power. If the pump runs for a short time and shuts off,after the power is restored,you have a bad accumulator. If it runs for a long time and shuts off,you have an inefficient pump and/or a leak. If the motor comes on while sitting with the ignition on and not touching the brake pedal,you have a leak for sure and the more severe the leak,the more often the pump will come on without touching the brake pedal. They,typically,become less efficient and leak more over a period of time. Without monitoring its performance,you don't discover that there is a problem until it is severe.
Thanks for the post
I thought if you had motor off and pressed pedal until accumulator totally disxharged and then turned key on the pump should run for about 8 seconds or so and you are good. Longer by less than say 10 more secomds and it is ball longer than that and internal leak or other problem?
Joel
I thought if you had motor off and pressed pedal until accumulator totally disxharged and then turned key on the pump should run for about 8 seconds or so and you are good. Longer by less than say 10 more secomds and it is ball longer than that and internal leak or other problem?
Joel
The accumulator is very similar to the water holding tank of a typical home with well water. The tank and accumulator are divided into two halves inside by a rubber bladder. On one side of the bladder is the water or brake fluid. On the other side is pressurized air for the well tank and nitrogen for the accumulator. The reason for a gas on one side is because gasses can be compressed. Liquids can not be compressed. Because the gas is on the other side of the bladder it's pressure rises as more fluid enters the other half. As we use some of the water or brake fluid,the pressurized gas continues to move the water or brake fluid. If we did not have a gas that could be compressed,the hydraulic pressure would rise instantly as the pump came on and it would fall instantly as the fluid was used. In both cases the pumps would turn off and on rapidly and continually. In the case of the well,you would add air pressure to the air side of the tank,through the schrader valve if you noticed your well pump doing this. For the Powermaster,our only choice is to buy a new accumulator because they don't come with a schrader valve to refill the gas side after the gas leaks out.
The pump will run when power is restored. Nobody will remember to periodically test the PM, and even if they do, it could fail far from home. The PM is as reliable as a Walbro fuel pump. And if it fails, try getting parts in Tim Buck Too.
I agree. They've both served me well.
