I removed the OEM hydraulic cylinder assist power steering on our MC-8 and installed a Ross HFB64 integral power steering. Got everything hooked up, filled reservoir and started the engine. With front wheels still blocked up, I turned lock to lock several times to bleed all air out of system. Everything seemed to be working OK. After removing the blocking, with weight on front wheels, I am getting very little power assist. I used ATF for the fluid (one of the fluids recommended on Bab Steering web site for this model & what was in the steering unit when I got it). I installed a gauge in the line and am showing 1100 PSI. Do I need to replace the pump with a higher pressure unit? If so, anyone have a brand and model number for the correct pump? Jack
Jack you should be good with 1000 to 1500 lbs try getting the poppet valves to set automatic by turning the wheel to the left with 40ft lbs of torque on the wheel do the same to the right turn,poppet valves let the pressure by pass if not set right the pressure is not there.
If the unit came from a different type vehicle they will need to be set again, wheels need to be off the ground to set the poppet valves
good luck
Thanks Clifford. Are the poppet valve adjustable from the outside of the steering box? Are they a screw with a locknut?
Probably does not translate but the Sheppard (stock later MCI) integral PS on my bus had virtually no boost when not moving with a stock pump, which was around 1200 psi. I had to replace with a Vickers VTM 40 set at 2000 PSI to get assist standing still.
FWIW, etc.
Brian
You change the pump for flow if he needs more pressure you just buy the valve set at the pressure you want you just remove the roll pin and replace it.
Some of the Vickers have a adjustable pressure valve but now most are pre set cost you around 35 bucks a few years back.
I have a 1800 lb valve Jack I can send you if you need it
good luck
Jack,
It's been well over ten years now but when I had some steering questions, I talked to the support folks at Bab. They were most helpful and knowledgeable. At least one guy there knew everything there was to know about the ram steering on my 4104.
I don't know if they still have the same attitude today, but it is worth a call.
Straight Line Steering is the place to go shoot Mark a pm from their site and he will send you the answers or call them 408-289-9850
good luck
Does anyone know if this Ross box can be used on a 4104? Haven't had any luck finding which Ross box to look for.
Jack i have a 2000 PSI valve around here somewhere, you are welcome to it. I bought it to upgrade my existing pump but the old valve was corroded in and I screwed it up trying to get it out. I should have just let the pump pressure shoot in out, but that didn't work.
Brian
Next time you have that problem Brian hook a grease gun to it comes out nice and easy I tried using the steering pressure to blow one out was not a nice sight never did find all the parts LOL
good luck
Jack,
This is very old information from R.H.Sheppard Co.INC for the change over on the PD4104 to Sheppard steering.
They Sheppard suggest using a Vickers VTM 42 pump with a pressure relief of 1750 PSI and a flow rate of 4.36 GPM at idle and
5.3GPM at fast Idle.
Hope this helps.
jlv
Guys he installed a Ross not a Sheppard unit
good luck
Jack, Let me know what you find out. I am having the same problem with my upgrade from an HF64 to the HFB64 using the Eaton B pump.
Tom Hamrick
Quote from: tomhamrick on September 01, 2011, 11:48:22 AM
Jack, Let me know what you find out. I am having the same problem with my upgrade from an HF64 to the HFB64 using the Eaton B pump.
Tom Hamrick
Tom,
How much pressure are you getting at the pump? I am still researching, trying to get more information about how to adjust the valves. With front end blocked up, it works OK . But with weight on the wheels, sitting still, virtually no assist. Give me a call tomorrow morning 863-444-3400 so we can compare notes. Not sure what pump I am using other than it is the OEM pump used with the saginaw hydraulic cylinder assist steering. Jack
Quote from: kaptar on August 30, 2011, 11:15:13 AM
Does anyone know if this Ross box can be used on a 4104? Haven't had any luck finding which Ross box to look for.
Ross only made one axle mount gear that I know of, it was used on the MCI 96A2. They are very hard to find. If you could find one I think it makes a better driving bus because the free play is adjustable.
Ken
Guys, you should get all the info you need from this site they have the TRW books you can download free I tried to scan mine and post it for you, this scanning and posting sucks for a old guy
http://phoenixex.com/technical-information (http://phoenixex.com/technical-information)
good luck
Those guys are in Dallas they also will help you solve a problem over the phone not PM's
good luck
Just a thought did you check the filters? theres two.
Quote from: biff on September 01, 2011, 05:22:38 PM
Just a thought did you check the filters? theres two.
I have not checked the filters, but everything was working with the OEM system, just more play than I felt comfortable with. After installing the used Ross steering gearbox the problem began. Jack
I was beginning to get a little jealous about you guys with power steering on your coaches, but then after just two months with our bus that has no power steering, look at my awesome physique!
Jack, you might recall that I have a Ross integral steering box from an MCI-9 on my 4104. I had to put a 2000 psi relief valve in my Vickers pump. It steers real good now, almost easy.
Kaptar, the key is getting the Ross integral steering box, from an MCI 96A2 which is axle-mount. Because I could only find one from an MCI-9 (not a 96A2) I had to fabricate a half-inch steel plate and attach it to the axle, and then mounted the steering box on the plate.
Hope this helps.
Hmm... didn't mean to underline everything... the underline got out from underneath me. Just wanted to underline the word "integral".
Kirby thanks for the help. I'm going to try to find the Ross numbers for these MCI boxes to see if they came in any other vehicles to make my search easier. Thanks again...Harry
Problem solved!!!!
I replaced the 1000 PSI pressure relief valve with a 2000 PSI relief valve and steering is easy enough that I can turn the steering wheel with a couple fingers with the bus sitting still.
After installing the higher pressure valve, I found that the poppett valves were already correctly adjusted. Gauge shows 1800 PSI when turning with the bus sitting still and drops off considerably when the poppett valve opens, as the wheels reach full turn.
Thanks for all the help, Jack
Question for you Jack how were you getting 1300 lbs with a 1000 lb relief valve or was that Tom with the 1300 lbs lot of the tour operator that don't do much city driving like the lower pressure for the highway driving I removed 2000 lbs valves and replaced with a 1500 lb valve,the mountain,snow and ice drivers just like a little assist they prefer not to have easy power steering but snow and ice driving is not a problem in FL lol glad you made it work
good luck
Quote from: luvrbus on September 13, 2011, 04:05:43 PM
Question for you Jack how were you getting 1300 lbs with a 1000 lb relief valve or was that Tom with the 1300 lbs lot of the tour operator that don't do much city driving like the lower pressure for the highway driving I removed 2000 lbs valves and replaced with a 1500 lb valve,the mountain,snow and ice drivers just like a little assist they prefer not to have easy power steering but snow and ice driving is not a problem in FL lol glad you made it work
good luck
Must have been Tom that was getting 1300, I was showing 1100 on the gauge with the 1000 PSI relief valve. I felt that the old gauge could have been off 100 PSI. Hope I never have to drive our bus in snow or ice. Our policy is "frost 3 mornings in a row, head further south" LOL Jack
I was getting 1200 pounds before I fixed mine. What I have is the Eaton B model pump that has the pressure relief valve outside of the front mounted resevoir. Jerry Jefferson's pump rebuilder advised me to take the 1 inch plug off the holds the valve and place a 1/32 thick washer inside the plug. This makes the spring harder to compress and increased my pressure to 1800 pounds. I also can now turn mine while sitting still. Cheap fix. The rebuilder also said that doing this on the Eaton B pump would shorten the life of the pump, but no more that I drive it will last forever.
Tom Hamrick
1984 Eagle 10S
Tom, fwiw I drove my Eagle with a B pump set at 1950 lbs for 20 years with no problem and Matt is still racking up the miles on the bus same pump bunch of Eagle guys had the B pump and still running without trouble
good luck
Thank Clifford! That is good to know.
Tom Hamrick
Tom. everyone has a choice but I like the B pump they are gear driven and you don't worry about losing the flex coupling or a fork like on a Vickers then if they leak it is to the outside not into the engine
good luck