Hi Jon Frosr,
Welcome to iRV2. I have the Howard Precision Steering System (HPSS) on my coach. There should be a small console in the driver's area of the cockpit. The console will have:
1. on/off switch
2. PSI gage
3. Trim button (large yellow button)
4. PSI knob.
1. Before starting the engine turn the system on (with the on/off switch).
2. Start the engine.
3. Does the gage show a build up of PSI?
4. If not, turn the PSI knob clockwise to increase or counter clockwise to decrease the PSI. On normal travel days I run at 120 PSI. On really windy days I up the PSI to whatever allows the HPSS control the coach.
5. Drive the coach. If the coach pulls left or right, get the coach moving in a straight line. Press and hold the Trim Button for a couple of seconds. Release the Trim Button. The coach should continue in a straight line (for the most part).
When environmental situations change you will need to repeat step 5.
I can go for weeks without re-trimming the HPSS. However, there are those days when mother nature has a cross wind with my name on it. On days like that I may re-trim several time throughout the day.
As to maintenance, there is a sight glass for the hydraulic fluid. The fluid level in the sight glass should be about 3/4", from the top of the sight glass. Take this reading with the system turned off.
Because HPSS is out of business, one can use any power steering fluid that meets MIL H 5606 specs. This is basically any modern power steering fluid.
You may need to get a couple of thousand miles under your belt to get comfortable with the feel of the HPSS and trimming process. I leave my HPSS on all the time.
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
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