It Said “Machine Moves Slowly”Thursday, September 1, 2011
It said, “Machine moves slowly.” That was an e-mail message I received one day from a road service tech. It went on to say that the equipment, an American Lincoln Model 7760 sweeper/scrubber had not been maintained properly for a while and needed some attention; i.e. brushes, squeegees and perhaps the hopper filter. Ron went on to say, however, that he had to resolve the main problem. Can you advise what to look for and to help going in the right direction?
I answered, “sure, we’ll give it a try.”
To begin, the Model 7760 American Lincoln is a large rider sweeper/scrubber. It is available in gas, but usually LPG. The cleaning surface path is 50 inches. The debris hopper has a capacity around 1,200 lbs. The solution tank capacity is 100 gallons. This is almost two 55-gallon drums, so the capacity is quite large. Along with this to help operate everything is a very complicated and extensive hydraulic system. Practically everything runs off hydraulics on this sweeper/scrubber. From the hopper vacuum motor, hopper lift cylinders, main and side sweeping brush motors along with the scrubbing brush motors.
Included in the hydraulics are also the main propelling motor and the rear drive wheel motor. The propelling motor is connected directly to the 1/C Engine. This is your main motor that all others run off. These leads me to the rear wheel drive motor. If one were to refer to the “general troubleshooting guide” in the American Lincoln service manual it lists four probably causes to the “machine moves slowly” problem. They are:
- Low hydraulic oil level. This is an easy one because you just add fluid. If it were only that simple! If this is your remedy, you lucked out.
- Brake dragging is also an easy one. Just check the brakes and perhaps they are hanging up.
- Hydraulic oil temperature is too high. Again, check the oil level and add SAE 5, Type F.
- A worn main propelling motor or drive wheel motor, in my experience through the years it has been either low hydraulic (which is an easy fix) or one of the motors are worn. I have found more often than not, it is the rear wheel drive motor.
Usually it is accompanied with leaking hydraulic fluid around the shaft onto the tire and eventually onto the surface. So I explained to look for this fluid or drops of fluid on the floor surface when the machine is moving. He came back with an affirmative on the motor leaking. I told him that I am going to take a chance and say it is the wheel motor and that is bad!
With this being said, there are a couple of choices for the desired remedy. You can:
- Simply replace the motor with a new one. This is the most straight forward way., and the most expensive way. This all depends on #2 and #3. However that’s the chance you take.
- Sending the motor out for repair. If the hydraulic motor is not your bag, contracting the motor out for repair is a legitimate alternative to new. Most of the time in this instance, you must be able to be prepared for a lot of down-time. You know that down time is costly.
- Repairing the hydraulic motor yourself is a choice. If you are a service tech that isn’t familiar with the insides of a wheel motor but wants to tear into it, this is my advise. First, get a price and availability on a new motor. If you are resolved to the fact that a new one maybe in your future, then tear into the old one first. What’s the worst that’s going to happen? Ruin a motor that is already broke. Who knows you may find something that could be easily repaired. Perhaps it is the shaft and bearing that only needs replaced.
So folks, I hate to leave you hanging on this topic. To see the conclusion I am going to pick-up next month where we left off. We are going to rebuild this wheel motor. See if Ron can rebuild this motor or if a new motor, is in his future.
It is always a pleasure to hear from my readers so send me an e-mail at Creamerscorner@hi-gear.com