Power Steering ID Please - 8V71 in a 4106

travlinman · February 22, 2011, 12:09:41 PM

Ok Bus Nuts I need some help on this one. My favorite mechanic, who shall remain nameless for now, replaced the lines on my power steering and now it howls like the devil. So here are a couple of photos of my set up. First, what type of set up do I have? Second, what type of fluid should be in there? Once we figure this out I will tell more of the story.

Thanks

TM

Len Silva · February 22, 2011, 01:08:16 PM

You may have air in the lines. Check your manual on the proper procedure to bleed them. I think it involves jacking up the front and turning the wheels from side to side BUT NOT AGAINST THE STOPS.

gmbusguy1 · February 22, 2011, 01:48:08 PM

TM, Could it be that the replacement pump is not the same rotation pump as the one removed???

Chris

travlinman · February 22, 2011, 01:55:33 PM

Chris,

The pump was not replaced, just the worn lines in the engine compartment. That and the fluid, which has me assuming that the fluid must me the culprit.

TM

wildbob24 · February 22, 2011, 02:46:40 PM

TM,

It's hard to say since both systems use the Vickers pump. You're gonna need to look up front and see if you have the power assist cylinder, in which case you use ATF, or, if your bus has been converted to a Shepard steering gear, you use 10w30 or 10w40 motor oil.

As Len posted, they make a lot of noise if there is air in the system, so the bleeding procedure is pretty important

Bob

luvrbus · February 22, 2011, 02:47:30 PM

Could be the oil looking at your photo that Vickers pump should have 10w or ATF 30 or 40 w engine will make it noisy some people don't mind the noise till the oil gets hot enough to pass through the valves

good luck

papatony · February 22, 2011, 02:55:11 PM

The Manuel calls for type A trans fluid in the steering.

travlinman · February 22, 2011, 03:41:23 PM

Bob,

Can you tell me where to shoot a photo of the steering gear?

Thanks

TM

Barn Owl · February 22, 2011, 04:16:07 PM

The gearbox will be sitting directly on top of your front axle.

Mine is doing the exact same thing. I had to remove the old pump and Sheppard steering box because my dad ran it 1800 miles without fluid. It did continue to work for a year but finally went out. I don't know if the PO ran power steering fluid or not, but that's what my father had put in it by the time I got the bus and I just continued to do the same without any noise. I then Installed a used system from NIMCO, and replaced all lines with new at the same time. The Sheppard system calls for 10w-40. Since then I have a very loud whine/vibration at start-up with cold oil but it goes away when it warms up. The noise comes from the copper lines vibrating that run down the middle from the steering pump pulses. I have managed to dampen it some with some foam but I am not willing to disassemble the entire bus to eliminate it especially since it is gone in less than a mile. I have been told that the copper pipe is not rated for the pressures that the Sheppard systems runs vs. the old assist setup, and that failure could happen. With that being said, I do not know of anyone that has had a pipe fail, and I have bigger things to worry about.

rampeyboy · February 22, 2011, 04:31:52 PM

"The Manuel calls for type A trans fluid in the steering."

I think my manual just says ATF. So either way, what happens if you use Dexron? I thought the biggest difference in the two was boiling point or something? Anyone else use Dexron? This is all very timely as my Scenicruiser power steering is inop, and the fluid isn't touching the dipstick.

Boyce

Barn Owl · February 22, 2011, 04:43:19 PM

Keep in mind that Sheppard steering was not an original steering setup, so what the manual recommends will not apply if yours has been converted.

For those who are thinking about it, the Sheppard steering conversion will allow for one finger turning at a standstill. An inexpensive and easy modification to a GM 4106 or newer. I don't know about the 4501.

travlinman · February 22, 2011, 05:03:20 PM

Barn Owl,

Thanks for sharing your experience, I will get some photos of the steering box tomorrow and post 'em up. You guys on this board rock!! Everyone, thanks again for sharing your knowledge.

TM

OneLapper · February 22, 2011, 06:53:41 PM

TM,

It's worth checking to be certain that your mechanic has the supply and return lines in the correct position on the power steering reservoir. Been there, done that.

travlinman · February 22, 2011, 07:37:50 PM

OneLapper,

Care to share a photo or two of how it should be done?

TM

baker4106 · February 23, 2011, 03:27:27 PM

Doesn't look like my power steering that is factory. Look for a large hydraulic cylinder on the steering arm. Sounds like air in the lines. Does it work but just noisey?