Hydraboost and Power steering issues

[Fultz1275]

Need help. I am running Hydratech's Hydraboost on my 68 Chevelle. I'm running the stock PS pump and an AGR quick ratio steering box. Everything works fine on the street, but when I autocross, the minute I stab the brakes into the first corner i immediately get a loud growling from the PS pump that lasts until i finish the run and park it. this past weekend of autocrossing the PS pump started Growling even more when I would turn the steering wheel and fluid was spewing onto the ground. Fluid foaming badly out of resivour.

some have explained that when I actuate the brakes hard the accumulator in the hydraboost system sucks the fluid out of the PS resivour and causes the PS pump to suck in air which causes the foaming of the fluid (air in the fluid). If this is the case, how do I prevent this from happening. Would a GM type II pump fix this.

My next option is to yank the Hydraboost and go with manual brakes.

Any help is greatly appreciated.

[sgernon]

I have hydraboost on my car and have run it pretty hard for the last 2 years without the issues you are describing. My setup was taken off an Astro van and I retained the external tank as well. Sounds like you believe the issue is fluid capacity as well. Have you thought about adding an external PS tank for it?

[csouth]

I don't know if just the type II pump would fix this without a reservoir with some sort of baffle? Have you asked AGR or maybe even contact Lee Manufacturing, both could offer advice on PS and hydroboost setup.

[Bled6904]

Ran into a similar issue with my 70 Mach 1 build. The type II pump should meet the fluid demands you need but as someone already mentioned the fluid demand is very high. Check out PSC steering. They make large good looking reservoirs that have a large feed (-10 i think)for the pump, (2) return ports for steering and hydroboost, and also have a baffle/filter. Solved all my problems and cleaned up my plumbing because of the lack of the "T" fitting for the return. Also keep in mind the new hydroboost units do make a little noise for a little while, but not what you seem to be experiencing.

[Hydratech®]

Since the power steering / hydraulic brake assist system is functioning properly in general street use, but getting pissy when you throw it into the first HARD corner in Auto X, the PS fluid in the reservoir must be sloshing away from the pump feed port in the bottom of the PS reservoir allowing the pump to suck in a large gulp of air (hard G's can put the fluid everywhere else but at the bottom of the PS reservoir where it needs to be!)(same discussions apply to fuel and oiling systems too). This then immediately creates fluid foaming creating the exact condition you are describing (as the PS pump took in a big gulp of air and then pulverized it into suspension in the PS fluid) - imagine taking a quart of PS fluid and putting in a blender and then hitting puree. The stock '68 Chevelle reservoir was actually one of the smallest ones GM ever ran - round bottom section with a thin tall neck. Swapping in a later model "canned ham" sheetmetal reservoir would add a considerable amount of capacity. Hard G maneuvers in a high RPM scenario would actually do best to modify the PS system for use with this stellar remote reservoir design that will provide smooth de-aerated PS fluid feed to the pump at all times (the large capacity and internal filter doing the magic of straining air out of suspension in the PS fluid):

http://www.pscmotorsports.com/gen-iv-6-hydroboost-reservoir-w-filter.html

http://www.pscmotorsports.com/pro-touring-p-s-remote-reservoir-w-filter-for-hydro-boost-brakes.html


Here is some further reading that may help:

https://www.pro-touring.com/showthread.php?75341-hydro-boost-on-track


Do please feel free to call our guy Jim Petty - he is a veteran circle track racer that REALLY knows his stuff:

http://www.hydratechbraking.com/contact.html

There are many different options so solve your scenario - yap with Jim for a few to see what may work best for you.

Here is some accumulator tech:

The accumulator is controlled by a pressure directional check valve system within the brake unit. When you start the engine, with no load on the brake pedal or steering, this will charge the accumulator to the no PS load pressure of roughly 100 PSI. When you apply the brakes or steer the vehicle, this raises the PS system pressures to 1000+ PSI when under load, and the directional check valve allows this pressure to store in the accumulator (via the directional function of the check valve). If your PS pump max pressure relief is say 1500 PSI, you will achieve this pressure level when the steering wheel is cranked all the way full left / right, and this pressure will then be stored in the accumulator.

Note that any time the engine is running, with the PS system functional, that you will not observe any loss of braking functionality - many people drive around for years with a "dead" accumulator and never notice. The only time the accumulator comes into direct play is in the event that you experience and engine stall while the vehicle is at speed, then providing typically 2-3 power assisted stops. Once the charge level in the accumulator is depleted through repeated pedal application with the engine off, you will still always have the manual brake actuation available.



There IS a difference - Thank you for choosing Hydratech!

:6gears:

[Fultz1275]

thanks to everyone for all the help. Looks like i have some work to do. :)