power steering

[rickdesilva]

When I park my bus in the garage I sort of tuck her into a corner. So when I start her up to take her out I have to crank the wheel to the right to get her out . No big deal. My bus has been idle for a few weeks. Yesterday, I went to pull her out and did the normal routine. Start up, build air etc. but it was like I had no power steering! I did a back and forth right crank until I cleared the garage then she seemed OK. Putting her away, All operations seemed normal "tucking" her back in. Today I figured I would try again and the same thing..no power steering so, I put my athletic supporter on and grunted her out and then after rolling forward a bit everything seemed fine. The PS fluid level is fine and reving the engine made no difference in the inability to steer. Any ever experience this? No problems at all once underway only at the start up. Any thoughts would be appreciated.

[Jon Wehrenberg]

I'm clueless Rick, but since steering is not something to be without I would get on the horn to the Prevost experts, possibly at the engineering level. Since power steering pumps are merely gear pumps they either work or they don't, so I suspect you issue has to do with valving in the steering sector. Why it happens is the question.

FWIW, if you want a little help when the steering is not working lift the tag. It won't make the steering stop malfuncting (I made that word up, Lew) but it takes a little weight off the front end.

[rickdesilva]

Thanks Jon,
I haven't tried it yet, but I think it may be related to the front height. I don't move until all systems are ready but perhaps your suggestion of lifting the tag or perhaps raising the front manually will help. I'll let you know!

[Jon Wehrenberg]

I suggested lifting the tag to take a little weight off the front axle so when it does not work in close quarters the effort to turn the wheel will not be as great.

I don't think the ride height affects the power steering. The front ride height definitely affects handling, but I can't imagine the power steering would be disabled if the bus is up or down.

[garyde]

After driving all day, I turned off my engine to go inside to register at an RV Park. When I came back out and fired up the Coach, my power steering did not work. I moved the Coach forward 20 or so feet and suddenly it worked. That was almost two years ago and I have not had the problem again. I guess it was a hic up with the pump, or the fluid was too hot, or some other one time event.

[Petervs]

Interesting subject. I think we all agree it should not operate this way. Something is amiss.

Lifting the tag would be a stopgap measure to help move the coach only, not a correct way to solve this problem.

When you lift the tag the steering should get easier because the weight on the front axle decreases by about 10% ( do the math...it is not a significant amount in my opinion), and more so because the turning radius becomes better because the effective wheelbase is shorter, and there is less "squirming" of the tires in the back.

When you first start the engine, maybe the belt is slipping that drives the power steering pump? Maybe the pneumatic belt tensioner has not come up to pressure yet? maybe the belt or pulley is worn?

I would go back and look at the engine while it is running when the power steering is not operating correctly, you might learn a lot!

You could "work" the power steering a bit by just turning the wheel back and forth with the bus not moving to see if it gets going.

[Joe Cannarozzi]

Did you try shutting it off and restarting and did you try waiting longer?

I am surprised that they changed these things over to belt from gear driven???????????

Maybe it has an air pocket.

[truk4u]

It's gear driven unless they made a big change. Don't forget the more obvious possibility, air in the system. There is a procedure to purge out the air, but I don't remember the details.

[Petervs]

Yes of course it is gear driven. I guess I was thinking itsy bitsy little vehicles.

Anyway, the Prevost Car website has the instructions for troubleshooting and bleeding the system.

http://technicalpublications.prevost.../en/manuel.asp

Choose your model coach and year, click on technical publications, and then chapter 14, steering.

Good luck, and tell us what you find out to solve this problem.

[rickdesilva]

thanks for all the info, I haven't been out there yet....I'll report back