| Author | Message | ||
| Lin (66.245.216.207)
Rating: N/A |
Ever since we installed the power steering, which has a Ross pump and a Saganaw box, it has made a whining noise. A friend told me that replacing the transmission fluid in the system with a good hydralic oil might help to quite it down. Any opinions or suggestions? By the way, the system seems to work great otherwise. | ||
| BrianMCI96A3 (208.13.135.211) Rating: N/A |
In all honesty, it may quiet it down some if you used a heavier weight hyd fluid... BUT if the system is noisy because there is bearing wear or worse, then your best bet is to have the system inspected by a qualified mechanic. As a side note, many systems will work fine right up untill they fail! Brian | ||
| Marc Bourget (209.142.38.81) Rating: N/A |
Are you sure you don't have air in the system. This is a common cause of a whine. Did you route the hoses the same way as original factory installations? As for oil, I use std 30 st detergent. This was the recommendation of the instructor at a White Freightliner training program in power steering. Worked for me for years. Onward and Upward Marc Bourget | ||
| Ed Jewett (Kristinsgrandpa) (4.224.96.147)
Rating: N/A |
I think Marc is right about the air. I had a new Ford PU that had a similar problem. The power steering system had some parts replaced and I had to jack the front end up and work the steering wheel lock to lock to bleed all of it out.It will probably, eventually work out but is a nuisance till gone, if that is the problem. It might be worth a try, before replacing expensive parts. Ed | ||
| t gojenola (66.58.192.10)
Rating: N/A |
I just went through the same problem after installing sheppard steering on my 4106. Whined like hell when first started up, but the whine went away when the fluid warmed up to about 170. There were no leaks and all lines and fittings were new. Turned out to be a bad pump that sucked air either through the shaft seal or the pump housing itself. I put on a new vickers pump and the problem was solved. tg | ||
| Lin (66.245.216.207) Rating: N/A |
Marc, you are using 30w motor oil? I have not heard of that. What is the difference between motor oil and hydralic oil anyway? | ||
| Marc Bourget (209.142.38.81) Rating: N/A |
Didn't mention above but for 2 yrs I was a partner in a business and responsible for PS pump and box overhauls. I've used 30 wt in every vehicle that I've o'hauled engines (6) and two that required PS work. Unless you have it apart, I wouldn't change. The motor oil is a bit more viscous and it has detergent in it. Other than that, the only difficulty I had was the workers at the 15 Minute Lube places putting ATF despite my admonition to use 30wt Detergent. They didn't like draining and flushing the system but after the 2d time no more mistooks! Onward and Upward Marc Bourget | ||
| Henry R. Bergman, Jr. (Henryofcj) (67.136.241.239)
Rating: N/A |
I learned from another Crown Super Coach guy that turning the wheel from HARD lock to lock and holding it there for about 1 minute will help pump out the air. My steering was noisy with the new pump and hoses until I tried his advice. Worked like a dream. I now have very powerful and QUIET power steering. Also I am using and top off with just type A automatic transmission fluid and NOT 30 wt motoroil. My Crown has a Victor VT-42 RH pump. Good luck. | ||
| Marc Bourget (209.142.38.81) Rating: N/A |
Running over against the stop opens up the bypass and purges the lines pumping all the air (if any) back into the reservoir. Too agressive and you can overheat the pump and/or burn up the drive belts. Worst of all, the shear, if overdone, tears up the oil and you have to replace it bringing you back to square one Onward and Upward | ||
| BrianMCI96A3 (69.34.171.129) Rating: N/A |
Do not under any circumstances hold the wheel at full lock for more than a few seconds! A full minute of full lock is causing damage to SOMETHING. Everything Marc talked about is true and happens very fast when you running against the stop, causing the pressure relief valve to open, creating a huge load on the system... as well as introducing loads of heat and friction to the fluid. My personal method of removing air from a power steering system is to turn the wheel to full lock MOMENTARILY in one direction and back to full lock in the other, it should not require more than a couple of cycles to remove any air. Brian | ||
| Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A |
OK guys, I hear what your are saying--no real debate here. The question is how can real world routine situations like turning the steering wheel all the way til it stops, then holding it there for a bit, be soosss destroying to the system? Some help here please. Please explain how damage can occur. What about the physical snubbers? I turn my Crown like this all the time. Auuughhh! I really do not think (respectfully) that The design engineers ... ...would have designed such a shortcoming/weakness into a what is otherwise an excellent power steering system. I can turn my Crown wheel with only one index finger lock to lock in soft dirt. What am I missing? And...I still believe it is possible that some of you guys were in fact starship engineers in a prior life sent here to help out us dummies. I need to learn more about power steering systems. Let me have it. CROWNS FOREVER!!!  | ||
| dougthebonifiedbusnut (24.62.99.43)
Rating: N/A |
haven't looked into the reasons but I was having al kinds of noise from my piece of bleep vickers pump until a friend told me to hold the wheel against the stops for between 30 seconds and one minute and the air will be dispersed from the system. All I can tell you is it worked. and I'm with Henry If thats all it took to develope catastrophic conditions the manufacturers would desighn the systems differently.Piece of bleep still leeks so I had a machine make me a new better cover. | ||
| Marc Bourget (209.142.38.81) Rating: N/A |
Hey Guys, Rather than be accused of pontificating, If you don't want to take our word for it, take the logic path we traverse when considering your question and look at the hydraulic circuit(s) diagram for your power steering system. Then ask yourself will the air caught in the system be nicely circulated through the system and back to the reservoir by turning the wheel from lock to lock which, in turn, passes the most volume through the system, purging it out and returning the highest volume (at normal temp and pressure) to the reservoir allowing the air the best chance to percolate out Or do you think that running the wheel all the way in one direction and holding it there, minimizing the flow volume through the total system (preventing trapped air from being purged to the reservior) and, which runs the pressure to Valhalla, maximizing the stress on the fluid, while short cycling the fluid from the pump to the reservoir and back to the pump, sidestepping circulation through the full system, with tremendous turbulence and heat generation. Which way is going to remove the air trapped in the system at minimal stress and expense? Don't take our word for it, figure it out for yourself! Onward and Upward Marc Bourget | ||
| Gary McFarland (Gearheadgary) (68.79.101.181)
Rating: N/A |
I've never heard of anything but turning the wheel from lock to lock to purge the system. Gary | ||
| Lin (66.245.216.207)
Rating: N/A |
I tried both methods. Of course, I am not sure that air in the system is the problem. Anyway the moaning sound may have decreased, but I will have to evaluate that later. While holding the wheel to a locked position, the noise completely stopped. My moment of elation was short-lived since I quickly realized that I had ground up and thrown the drive belt. According to Murphy's Law, it had to be the innermost belt. I will be less agressive in the future. But I've got to tell you what has really got me confused. Although the belt was ground up and thrown completely clear so I could pick it up, it was not broken. How did it get past the other three pulleys and belts to come off? | ||
| Derek (Derek_L) (24.83.196.239)
Rating: N/A |
You had one of those magic belts. Either that, or the first belt came off and the other two skipped over. | ||
| Dwight (67.213.8.21) Rating: N/A |
You need to jack up the two front wheels and then turn the steering full left and full right (about 20 times), under pressure some of the trapped air gets compressed in cavities and can not escape to the reservoir. Try it you'll like it... | ||
| Marc Bourget (209.142.38.81) Rating: N/A |
To Dwight (who obviously understands) and others who haven't turned their attention to the issue. Raising the front wheels off the ground reduces the max system pressure required to turn the wheels against the scrub radius. This prevents the chance that the bypass will open and maximizes the speed/volume of oil flow through the system, back to the reservior, increasing the chances that the "trapped" air pockets will be "washed" through and purged. Onward and Upward Marc Bourget | ||
| Marc Bourget (209.142.38.81) Rating: N/A |
Lin, Moral of the "Fan Belt Story" - learned, finally, after 38 yrs driving civilian and professional I had the inner belt fail on my Crew Cab Dually while on the Fwy in Los Angeles, It flopped around the crank pulley and took out all three belts. Didn't dawn on me until I took the next offramp and tried to stop at the bottom of the incline where 6 cars were waiting for a green. The Dually has hydroboost powering the brakes, and with the departure of the belts, so went what ever braking authority I thought I had. Had both feet on the brake pedal, straining hard enough to lift me off the seat and actaully bend the steering wheel, but barely slowed - but just enough to permit the light to go green and me run the intersection without committing vehicular sodomy! The lesson, I had just finished overhauling the engine and was too cheap, lazy, whatever, to replace the fan belts which had been on the vehicle for over 10 years. I'm no ace mechanic. I do have my nugatory moments! Onward and Upward Marc Bourget | ||
| Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A |
Hey Lin, don't 'ya know that is why the engineers used fan belts to power our power steering pumps anyway? Sooos they will break and fall off at the worse possible time! Auugghhhh! My Crown's Victors VT-42 RH pump (expensive!) blew up big time in Sacramento CA when I was driving the old girl North from Bakersfield CA to Cave Junction OR where I live. No doubt is was burning up. Smoke, stink, oil everywhere and stuff. Since I was a dummy and had no tool kit I cut both the brand new belts. Drove the Crown home with no power assist, but no problem. Just steered hard at low speed. Anyway, had the pump changed out and as one of the long hydralic hoses was leaking also, changed both of them out too. Both were nearly 28 years old. Anyway, with both hoses being empty, we had an ongoing problem getting all the air out of the system. Then a fellow Crown Super Coach buddy suggested using the steering wheel lock to lock procedure, holding the wheel at lock for about 30 seconds. Seemed to cure the problem. Marc, please bear with me on this. I hear what you are saying and nearly all the time, your advise and wisdom is dead accurate, but this time, with all respect, I do not believe the by passed oil would experience that much dangerous pressure. Again, this is my opinion possibly not backed up by actual facts. And again, my particular situation trying to purge two new long dry hoses did not leave me any real alternative. When my new power system blows up, I will let everyone know sooss you can laugh at me. Auuggghhhh! | ||
| Lin (66.245.217.88) Rating: N/A |
I replaced the power steering drive belt today. The other belts look fine and although they are a number of years old, there has not been much use on them. Anyway, maybe next week I'll get a chance to deal with the noice again. I'll try lifting the front wheels and turning it lock to lock a bunch of times. I don't know about the pressure in the system getting critically high while holding the wheel to one lock, I do know that it must have stopped the pump and thereby devoured the belt. The funny thing is that while holding it at the lock one time, the noise stopped so I felt encouraged to do it more. Now I know that the reason the noise stopped is that the pump stopped. These things offer great educational opportunites, don't they. | ||
| Marc Bourget (209.142.38.81) Rating: N/A |
Henry, You're fine, but I may not be explaining myself very well. I tried by reference to the power steering system schematic. Let me try again, for you and the other open minded readers and see if I can communicate better this time. I don't know what box you have, but typically there's a dual-action piston controlled by the spool valve. When you run the wheel all the way to the left, the piston is at the limit of it's travel. Little if any circulation through the hoses occurs, because there's no more room. Once you get to the end, that's all the benefit you're going to get towards purging the system as a whole. You need to get the aerated fluid in the acutating piston back to the pump reservoir so that the air will percolate out. the best way to do this is through fluid flow like washing down your driveway with a hose, or, more accurately, hydro-jetting a sewer What happens when you get to the end of the piston travel is a big jump in pressure that opens the bypass valve and the oil is pumped from the pump vane cavity to the reservoir, back to the pump vane cavitiy. I probably travels all of 3" total, over and over, and never to the "Rest of the System" where the air is waiting to be purged. This hydraulic short circuit "jes don't do it" i.e., purge air from the "Rest of the System" Temps will go up. "Shear" is imposed on the oil. Oil ain't a nice neat ball like a marble. It's a long snaky, branched molecule thing that can "cleave" or "lyse" (think of a really small wishbone!) with temperature and mechanical stress. Pumping at high pressure through the narrow aperature of a bypass valve imposes lots of mechanical stress, called "Shear" moreso than the pump vanes do in normal operation. I guess if I used the word "dangerous" before, I oversold the idea and therefore apologize. What I meant to say is that sheared oil requires replacement and having to do so puts you back in the position of having to purge air. You can go and shear your oil all you want. As your pump vanes spin their merry little paths about that cast pump housing, metal wiskers will shed, moreso as the oil is sheared and its viscous properties wane. These wiskers are almost as effective as sand paper with the expected results on the spool valve seals, bushing/bearings and shaft seals. These wiskers are what I was referencing when I said to get some plastic "button" magnets and put them in the reservoir. Like the Fram guy said; "You can pay me now or pay me later" Car sized parts aren't a problem. Bus/Truck ones are! You makes your choice and pays your price, but holding the wheel against the stop don't get the air out of the system, IMHO. Your mileage may vary" Hope I was clearer this time! Onward and Upward Marc Bourget | ||
| Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A |
Marc...what you have just said does make sense and I thank you. Now I know more about typical power steering systems. Now, can you tell me how to install and adjust a 425A Jake Brake assembly for my Big Cam Cummins? He he he. Thank you again. | ||
| Marc Bourget (209.142.38.81) Rating: N/A |
Henry, I'll soon know about Jakes and an 8V92 when the engine is assembled, but I don't thinks they's the same! (setups, that is!) Onward and Upward Marc Bourget | ||
| BrianMCI96A3 (69.34.169.50) Rating: N/A |
Just one further note, I've gone through several Hydraulics courses over the years, and what Marc refers to as a bypass, is basically a relief valve. A relief valve will never operate unless system pressure exceeds normal operating range, it's basically a huge spring that holds the valve closed, pressure has to exceed the push of the spring, when it does the fluid will squeal past the cracked open valve, which is why you hear that squeal when someone cranks on the steering wheel at full lock. Henry's belt flipped because of this increased load on the pump. In my "Hands On Hydraulic Training" I was never so impressed as the experiment whereby we routed full pump pressure through a relief valve and directly back to the tank. The relief valve squealed and got hot to the touch within a matter of seconds... almost too hot to touch. Brian | ||
| Marc Bourget (209.142.38.81) Rating: N/A |
Brian, Please excuse me for my lazy terminology. I kinda combined them(and used interchangably) because the relief valve, in opening, bypasses the system, dumping the oil back into the reservoir, or that is how I explained it to myself Thanks for the correction. We had a test bench at the rebuild shop. The flowmeter was (at the time) an expensive puppy - even compared to a 1500# oil-filled pressure guage. I always associated the "squeal" with belt slippage, but mind you, there being no purpose in our use to push that "envelope" we didn't go there often. Thanks also for this addn'l info. Onward and Upward Marc Bourget | ||
| Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A |
Marc, I was just kidding about the Jake Brake on my Pancake Big Cam Cummins. Not yet ready nor can $afford$ to do soosss right now. Crown coach. Also....I just learned today from an E-mail Crown buddy that the Jake on a pancake Cummins is different from an upright mill. Never knew. All the neat things you learn and friends you make from reading this excellent board. My thanks to all you "Bus Nuts". |