Joined: Wed Aug 11 2010, 10:15AM
Location: E WA
Posts: 1230
Mike66Chryslers wrote ...
I was just pondering about Hydroboost this morning, and this seems to be the only thread on the Dock discussing it.
I wish Yatzee had chimed back in with specifics on what parts he used for this conversion, and required mods to the firewall bracket, brake pedal pushrod, etc.
Joined: Tue Oct 11 2005, 01:33AM
Location: Calgary, Alberta
Posts: 5893
I just came cross his thread and while very interesting, what happens if you throw/break your power steering belt? Do the brakes still work manually as they do now with a vacuum failure? I have 4 wheel disc brakes on my Fury and have zero problem getting it to stop fast and in a straight line.
Joined: Tue Oct 11 2005, 01:33AM
Location: Calgary, Alberta
Posts: 5893
Interesting, not sure how a reserve system would work in a hydraulic system unless it uses some sort of pressure tank. Isn't the reserve problem the reason why typical brake systems use either vacuum or compressed air for boost?
After sleeping on the idea of a "hydraulic booster" I'm afraid I don't really see much advantage other than to eliminate the physically big vacuum booster to reduce interference with large engines such as crate hemi's.
Joined: Sat Aug 19 2006, 05:03PM
Location: Ontario, Canada
Posts: 2919
Bill, there's a small pressure tank on the side of the hydroboost unit which is supposed to provide a couple of boosted stops before reverting to manual brakes, just like the case for vacuum assisted power brakes.
In addition to eliminating the large vacuum booster unit, it also allows power brakes for cars with engines that don't produce enough vacuum to use regular power brakes.
Joined: Wed Dec 21 2005, 07:34AM
Location: indiana
Posts: 791
Accumulators are used in such hydraulic systems to store the pressure, and they typically have a gas-filled bladder inside that the fluid pressure pushes against.
Lincoln Mark 7, 88-89 Thunderbird and some models of Jaguar use an accumulator.
The Linc and T-bird use an electric motor to provide braking boost, and an accumulator to store it, such that the system only runs the electric motor every 5 stops or so. I don't know how the Jag is set up other than it uses a similar accumulator.
Joined: Tue Oct 11 2005, 01:33AM
Location: Calgary, Alberta
Posts: 5893
Thank-you for that explanation. I'm not trying to be obtuse, I just couldn't see how a pure hydraulic system could provide residual pressure for brake application should the pump and/or engine stop running. I guess the advantage of the hydraulic boost is a much higher braking force whichj probably means the brake pedal is more sensitive. People who drive with one foot on the brake making their brake lights continually flash on and off would probably hate this type of system.
Personally I like the feel of manual brakes, they provide great feedback so that you can gauge exactly how close you are to a skid or slide. Conventional power brakes make braking tricky on a wet or icy road because most of the mechanical feedback is lost or filtered by the booster. This feedback filtering has resulted in ABS braking systems which may protect you from a crash, but may give you a heart attack while you hang on a pray. Full air brakes are a joke on wet/icy roads, use your gears or hang on and pray. I don't know where hydraulic boost fits, probably somewhere between vacuum boost and full air.
Joined: Mon Oct 10 2005, 08:43PM
Location: Calgary, Alberta
Posts: 978
Fury440 wrote ...
I don't know where hydraulic boost fits, probably somewhere between vacuum boost and full air.
I used to have an 86 6.2 Chev van with hyroboost, while at the same time drove a company GMC van with vacuum assist. I felt no difference in the two units.
Joined: Sat Aug 19 2006, 05:03PM
Location: Ontario, Canada
Posts: 2919
My '94 Cummins had a vacuum pump connected to a vacuum brake booster. My '07 Cummins has hydroboost. For lack of a better word, it feels "normal". Before the '94 I had an '84 GMC van with 6.2L diesel. It probably had hydroboost, but I really don't remember. That van drove and stopped very well in the snow.
