Hydroboost and stalled engine

[65 drop top]

Just curious as to what happens with a hydroboost brake system if you have a stalled or non-running engine?

[badolds]

I am no expert but mine is an accumulator style. It has enough pressure saved in the system to stop the car if it dies. Even after the car has been off for several days you can still hear the hydraulic pressure when you press the brake pedal.

Dan

[astroracer]

Dan is right.
https://static1.pt-content.com/images/pt/2017/07/MVC010Fvi-1.jpg
The little gold cylinder in the middle of the pic is the pressure accumulation can. it will provide enough pressure for two or three stops if the engine or PS Pump dies.
Mark

[65 drop top]

Good to know, thanks. How is the overall pedal feel? I've heard they can be overly sensitive. I'd like the "new car feel" pedal, but would like to maintain enough control to not lock 'em up too easily.

[badolds]

The pedal does feel different but it is not unpleasant at all. My engine has a big cam and makes little vacuum so having brakes that actually work is awesome. I have had only one emergency stop since I converted the brakes to hydroboost and it was no problem to control. These units are used in stock vehicles from heavy duty trucks to mustangs so I think the pedal feel will be acceptable to you.

Dan

[astroracer]

Hydroboost has been around for LONG time, it's not new technology. For BadAst I am using a PS pump for a 1971 Chevy 1 ton truck that had hydroboost. The boost unit is off a '95 Astro Van.
The brakes will still work with no boost. It's really no different from losing boost on a vacuum M/C equipped vehicle. They still work, it just takes more effort to get them to work.
Mark

[USAZR1]

Do you have to change the p/s pump to run a hydroboost set-up?

[astroracer]

Do you have to change the p/s pump to run a hydroboost set-up?

You don't "have" to... but, a hydroboost pump is already set up with a return line fitting. Using a hydroboost pump is just cleaner and easier for running and routing the return lines.
Mark

[65 drop top]

So does the pedal or steering feel change if either one is being used heavily? For example, if you are hitting the brakes hard and then want to make a sharp turn, will the power steering pump make enough pressure to power both?

[astroracer]

So does the pedal or steering feel change if either one is being used heavily? For example, if you are hitting the brakes hard and then want to make a sharp turn, will the power steering pump make enough pressure to power both?

Like Dan stated above, both systems work fine under a panic mode and, like I said above, these systems have been around for a long time. If there was an issue with either the brakes or steering during a panic stop we would be well aware of it by now. I have been driving Astros with hydroboost since they came equipped with it and have had no issues.
Mark

[a67]

Note that not all hydroboost systems have the accumulator. So be sure to get one that does.

Bob.