Loss Of Steering

[djpauls]

On my return from Alaska last year my air compressor on my Cummins ISC 350 blew resulting in total loss of steering (the power steering pump runs off of the compressor). I could not physically move the steering wheel which caused a lot of excitement since I was traveling at 65mph at the time. Fortunately the steering was locked in the straight ahead position, the road was straight and there were no vehicles in my path. I did make it to the edge of the road by the time I stopped but I don't know if it was because of my efforts or the crown of the road. I shudder to think what might have happened at anytime over the previous month traveling the Canadian Rockies and Alaska.

The air compressor is lubricated by engine oil. The 3 inch hole in the case resulted in a near total loss of engine oil before I shut it down. Fortunately there was no engine damage and thanks to the efforts of Coachnet and Cummins of Lloydminster, AB Canada I was on the road in 2 days. Prior to my trip to Alaska I installed a Blue Ox TruCenter Steering control. Over the many years that I have driven vehicles i occasionally lost power steering but was able to control the vehicle.

My questions are: Does it seem reasonable that I had absolutely no steering control as a result of no power steering?

Should further checks be made on the steering components?

Any thoughts?

[dickandlois]

Hi Don, I have to agree with you regarding the total loss of steering. Might be worth a letter to the NTSB explaining the problem. It is hard for me to think that the loose of the power steering pumps could lead to one not being able to have some steering left.

Did you have any indication of the pending loose of the air compressor / drop in air pressure ?

The other item is that with the loss of air when it drops below 45 lbs the parking brake will engage. This locks the rear brakes and that is not what you want.

Where you able to reduce your speed with the air brakes while trying to steer to the side of the road?

From your information, I take it the 3in. hole was in the compressor.

Rich.

[desertdeals69]

When the compressor fails there is still air in the tanks for a couple of stops. The park brake does not lock the rear brakes but rather applies them moderately. Try putting the park brake on while going at moderate speed with no one around and you will see how they work. You come to a gradual stop.

[dickandlois]

Hi DD, When I pull on the park brake on our unit they do not come on slowly, they lock up as soon as they engage. No delay at all.

When I last took the RV driver safety course, the park brake question came up and unless I missed something, the answer I remember was never engage the park brake while driving of any reason-- the rear brakes will lock up as soon as they are applied.

Rich.

[wolfe10]

I can see no reason that loss of hydraulic assist would cause the steering to lock up.

To get an idea of the huge amount of effort required to turn the steering wheel without hydraulic assist, try turning the wheel with the engine stopped.

That should give you a good idea of the steering effort without hydraulic assist."

[djpauls]

While in the Cummins repair facility, I asked the service manager if he had seen any similar failures. He said that he had only seen 2 and they were vehicles that had many more miles than mine. Upon my return to Michigan I did an internet search and found that there were other instances and found a NHTSA recall ID# 01E011000 that specifically addressed the potential compressor failure and the consequence: "WITHOUT POWER ASSIST, THE VEHICLE BECOMES VERY DIFFICULT TO TURN AND COULD POSSIBLY RESULT IN VEHICLE CRASH."

The recall date was 3/14/2001 and appeared to include my motorhome. I bought the vehicle used in 2006. The catastrophic compressor failure was sudden. The crankshaft within the compressor broke and the hole was in the compressor case. The air reserve held enough pressure for necessary braking control. To their credit, Cummins reimbursed me for all repairs. I had a very good discussion with a Cummins customer advocate and I am satisfied with their response. He went into a great deal of detail about the recall and the specific chassis that were included in the recall. My Roadmaster was not included in the recall. Their reimbursement to me was "Good Will."

The part that seems not reasonable to me is that I could not turn the steering wheel at all. It was if it was mechanically locked. After the repairs, it steered normally. Currently it is in my "barn" and I have raised the front wheels off of the ground and can freely turn the steering wheel without the engine running and power assist.

Any additional thoughts?

[dickandlois]

The weight of the coach makes turning the steering wheel very difficult when there is no power assist.

You mentioned that the steering was free with the wheels off the ground, that test with out the engine running validates the system is free from any mechanical issues.

I drive with driving gloves most of the time, this gives me a better grip on the steering wheel and when the engine quiets on gas driven power steering pumps on most cars and trucks,that little extra allows one to turn the wheel a little easier.

Really makes one appreciate power steering.

The gear ratio in the steering gearbox changes how much force is required to turn the wheels, so you could ask if that is an option. Remember there are always tradeoffs though !!

Rich.

[desertdeals69]

DickandLois, on 21 Feb 2013 - 08:59, said:

Hi
DD, When I pull on the park brake on our unit they do not come on
slowly, they lock up as soon as they engage. No delay at all.

When I last took the RV driver safety course, the park brake question came up and unless I missed something, the answer I remember was never engage the park brake while driving of any reason-- the rear brakes will lock up as soon as they are applied.

Rich.

I was going on what the Spartan seminar presenter said. He tried it and it came to a gradual stop. There are springs that apply the park
brake. He was driving a bare chassis on a test drive. If you are going slow it may lock up but a higher speed its not supposed to lock up.

[C-677946]

I've driven 80,000 lb to 135,000 tractor trailer combinations that did not have power steering. I can tell your that you really work up a sweat steering at parking lot speeds, especially in the southern states. But at highway speeds there was not problem. That included one that had air controlled power assist steering that you would only turn on in parking lots. I would really be looking at that recall and at notifying the NHTSA. https://www-odi.nhtsa.dot.gov/ivoq/