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adamdegraff
09-30-2008, 11:32 PM
Quick question about howard power center steering.

When I'm driving and turn to the left, Howard PSI goes up to 100 (where it is set). When I turn to the right, it drops down to 45-50 PSI. I notice no difference in handling at all. When I turn right, I hear the air hissing out. When I turn left, I hear the air filling up.

Any thoughts? Just a leak?

Oh, also, does the trim button have any relation to Howard Power Center Steering? Or is that an unrelated system?

Thanks,
~Adam

0533
10-01-2008, 04:00 PM
I have Howard Power steering on my bus as well.

I have only used a few times, once or twice crossing from Coburg to Florida on some long straight legs, desert stuff with 45 Degree winds for several 100 miles.

There are three buttons, actually one is a knob, and the gauge.

Turn on the unit, turn the knob to get the pressure up to the desired level and position the wheel where you want it to stay, then set the trim.

I have a Howard manual if you need more info. I will look at it more carefully.

If there is a leak, it might be either air or the hydraulic cylinder. the parts and pieces are orange in color including the Hydraulic cylinder, which is next to the Prevost steering damper and can be seen in the steering bay under the drivers window. look for a leak at the hydraulic cylinder, a little residue does not mean much.

I am no expert but will get you more details if you need them. You will not find much online.

adamdegraff
10-01-2008, 06:14 PM
Thanks Bruce!

Am I to understand that the trim button works with the Howard system? I thought it was a Prevost thing. If the trim button is integrated in with the howard system, I may not have a problem after all. Maybe I just set my trim and this is the result.

I guess I may need to dig up the manual on the Howard system:-)

thanks,,
Adam

Ray Davis
10-01-2008, 06:39 PM
Adam

The trim is part of the Howard system, and is used to help you trim out cross-wind pressure while driving.

Under normal circumstances in a cross-wind, you have to keep pressure turning the steering wheel to one side or the other to counteract the wind pressure on the side of the coach.

With the Howard, you set your steering wheel (while driving) to compensate for continuous side winds. Then, momentarily press the trim button. This actuates the pressure rods to automatically give you that amount of pressure to hold the vehicle straight, without additional effort from you.

It's also said to perhaps be a help in the case of a flat tire, as it will help keep your wheels aimed straight (somewhat).

Ray

0533
10-01-2008, 06:42 PM
If you cannot find it, i will share mine with you. I did have what I thought was a problem when I first purchased my bus, it turned out to be nothing.

Here is an exchange I had with Sam Kopecky at old Howard Co, and my research on what was left of Howard. Maybe the contact and number is still good, as they are OB.


The orange cylinder that appears to be the source of most of the potential problems, leaks. Sam said that we can top of the reservoir and watch it (power steering fluid, its best to use aviation grade oil H5606 if available) or replace the cylinder with either part # 10A002-10-H this is a 10 inch cylinder or its 10A002-12-H for a 12 inch arm. If you do have a kit in stock it is somewhat difficult to change out the arm as the tolerances are very tight to the bracket. The replacement brackets do not exist for now.

anyway thats the news. let me know if you need more

Sam's who works for camping World was with Howard can provide details on the system and its details Cell# I think 1-210-422-8484

truk4u
10-01-2008, 06:46 PM
It wasn't designed for left/right turns, it's function is running down the road with crosswinds or I suppose a blow out. I thought it was just an added optional expense on my Marathon by the original owner. If you need Howard steering on a Prevost, something must be wrong!

jimshoen
10-01-2008, 06:53 PM
Adam,
I have the Service Manual for the Howard and repaired the leak on my unit. It works good and I use it most of the time. All of the time at speed.
Send me your regular e-mail (private) and I can send it to you. File too big to send here. Also, if I'd like to post the Service Manual on POG. What is the procedure?
Jim

garyde
10-01-2008, 09:23 PM
Truk, it's designed to allow those who need it, to nap.

0533
10-02-2008, 07:40 AM
I was told by Sam, The last living Howard employee that Howard was a perfectionist. The tolerances of his equipment where extraordinary, very high quality stuff. Marathon has tried to rebuild them and have found it to be too difficult and costly.

They sold about 4,000 of them mostly to long haul truckers mostly out west.

Jim Skiff
10-03-2008, 10:48 AM
Jim Shoen has provided us with this PDF which can be found here:

HOWARD PRECISION STEER WHEEL CONTROL SYSTEM (http://www.prevostownersgroup.com/users/BD83DEF1-CF1D-CEE2-5BF432431EE8B2E3/library/files/HPCSS_SERVICE_MANUAL_JAN_03%5B1%5D.pdf)