I had a pump failure in my old GMC (2001) and I had almost no brakes. There was no reserve pressure at all. The steering sucked too. I almost went in the ditch.

HydraBoost works, here it puts my brakes on fire. No lock up and engine is on power.

http://www.protouring.se/files/gullabo_braking.jpg

BTW, this is a professional racedriver, not me driving :cool:


Jan

Looks like manual it is. I'm going to take the car to Abs Power Brakes and let them sort it out. I like the idea of less parts and the manual setup. Less parts, less chance of failure.

Besides its more traditional :thumbsup:

I went manual as well, CNC dual MC with brake bias adjuster:
http://www.cncbrakes.com/mc.asp?grp=...718&subseries=
Check valves on both front & rear lines to reduce travel.

There's nothing wrong with concept of Hydroboost. Millions have been made over several decades.

If it loses pressure, and the reserve doesn't work, you get manual brakes. So it's strange that people say get manual brakes, because if hydroboost fails, you'll end up with manual brakes.

I put one in my car. Filling the fluid and waiting for it to de-burp is a pain. Other than that it is one toe braking. And I do shut off the engine and coast into the garage so manual braking is okay.

The difference is that you (typically) end up with a much smaller bore MC when doing a traditional manual brake set up.
If you have a power brake setup, with larger MC, you'll end up with a much higher pedal rate to achieve the same brake torque.

In a panic situation, you usually don't have the room to accommodate the decreased effectiveness of your brake.

Right. Also, there are two different pedal ratios between a manual set up compared to a power system.

Comparing a manual system, to a system set up for power assist that looses power assist, is not accurate.

That's true, but in many cars you can alter the pedal ratio and use power brakes too.

In the case of the nova the sudden loss of PS /PB caused the smack. But it was the fault of the fuel design not hydroboost.

In a panic situation, there's no way you could set the system to work similar to a manual setup. While you are correct, the discussion is more about the situation than the physics.

If the brakes rely upon the power steering (or pressure reserve) and they fail, it equals a brake failure.

I disagree -- the Hydroboost systems store enough pressure to operate the system for 2 or 3 braking operations. I cut and pasted this from Hydraboost FAQ's:
The bottle on the side of most hydraulic brake assist units is referred to as an accumulator or nitrogen reserve. This stores up hydraulic power steering pressure in the event of an engine stall condition, to provide reserve brake assist power for up to 3 applications of the brake, similar to how a vacuum booster would function in an engine stall condition.