I have seen improvements in the maintenance, the greasing program of the equipment appears well established. The staff reported a reduction of cutting unit roller bearing failure, and there can be seen a significant reduction in lift arm bushing wear, all of which contributes to consistent quality of cut.
All of the staff is eager to perform a quality job but the efforts appears to be hampered by some of the processes in place and not understanding what the maintenance practices entail.
One area that is an issue is the generation of maintenance work orders from the central office, one piece of equipment, Multi Pro 1750 (41188-314000274) that was looked at on 5/21/2015 with 659 hours had it last service on 4/14/2015 a 400 hour service at 426 hours. The required maintenance for this unit as per the operator’s manuals is every 100 hours “Change the engine oil (more often when operating under heavy load or in high temperature)” which both condition “heavy and high tempreture”exist at this location.
Looking closely at the work order it was noted that the 400 hour work order was based on a Multi Pro 5600 service schedule, the Multi Pro 5600 (model number 41568) was last made in 2003. The Multi Pro 5600 is very different machine from the Multi Pro 1750. The 5600 was fitted water cooled gas engine, the 1750 is an air cooled gas unit that requires a more frequent oil change.
The use of an equipment ID number or “ficha” without the use of the model and serial number of the unit may have contributed to this confusion. With a fleet as large as there is at this site, you will have units with the same name but will be very different, like a 1996 Toyota Corolla will be very different from a 2015 Toyota Corolla.
The importance of the use of model serial number is not only confined to maintenance practices but also extends to the ordering of the correct parts.
This was the document that the above work order was based on, I did not find the source of this document
Below is from the Multi Pro 1750 operator’s manual.
As can be seen the differences between the work order used and the maintenance schedule from the operator’s manual is very different.
Looking at the schedule as exists it appears staff might not be clear what each operation entails.
The is one common operation in both service shedules (for the 5800 and 1750) at 400 hours is the inspection of the nylon bushings of the boom pivots which does not appeared to have been performed.
This can be attributed to a lack of understanding of the operation by the line technician. The operation is plainly outlined in the operator’s manual,
At the top of the photo, you can see pieces of broken bushing (item 1 in preceding drawing)
When speaking with staff they are under the impression inspecting brakes involves simply pressing on the brake pedal.
Below is from the operators manual section on brake maintenance
Inspecting the Brakes
Service Interval: Every 100 hours
The brakes are a critical safety component of the sprayer.
Inspect them as follows:
• Inspect the brake shoes for wear or damage. If the lining (brake pad) thickness is less than 1.6 mm (1/16 inch), replace the brake shoes.
• Inspect the backing plate and other components for signs of excessive wear or deformation. If any deformation is found, replace the appropriate components.
Inspección de los frenos
Intervalo de mantenimiento: Cada 100 horas
Los frenos constituyen un componente de seguridad del fumigador de importancia vital. Inspecciónelos de la manera siguiente:
• Inspeccione las zapatas de freno para asegurarse de que no están desgastadas ni dañadas. Si el grosor de la Zapata es de menos de 1,6 mm, las zapatas deben ser cambiadas.
• Inspeccione el soporte y los demás componentes por si hubiera señales de desgaste o deformación excesivos. Si se encuentra alguna deformación, cambie los components en cuestión.
Checking brake pedal travel is only one step in proper brake inspection, on this 4 wheel disk brake vehicle other operations consists of removing the wheels and inspecting the inboard and outboard brake pads and the brake disk wear along with the parking brake system. Bake pad cannot be inspected without removing wheels.
200 gallon sprayers when loaded are carry nearly one ton of payload and are operated in demanding conditions. A fully functioning brake system is critical for safe and efficient operation.
My attention was drawing to the brake system when casually looking I found the parking brake was not working, an item crucial as this sprayer is fitted with a walking boom.
Parking brakes on this 200 gallon sprayer fitted with a walking boom, is critical for safe operation as the payload totals nearly one ton when the tank is full.
My inspection found the parking brakes inoperable due completely worn parking brake pads and the rear brakes inoperable for some time only the front brakes working and the pads were very worn. This condition could have been detected long before it reached this stated if it had been inspected as outlined in the operators manual, every 100 hours.
This unit with 659 hours would have been inspected 6 times in the last year, and at least two time since the last service at 426 hours on 4/14/2015.
It appears wheel have never been removed.
Front brake rotor with some wear
Front pads with wear, but stiil within specs , but time to check if replacement in stock.... thickness is more than 1.6 mm (1/16 inch)
Rear brakes, brake disc, brake pads and parking brake need to be replaced
Rear brake disc, brake pads and parking brake pads need to be replaced
Part of the brake inspection is to check the wheel bearings for play in thios case it is time to inspect repack and adjust bearing preload.
Trying to perform services without a lift many areas can be over looked such as grease points as can be seen on the same Multi Pro 1750 drive shaft
Tool expense is always great concern to management as often the indirect cost of equipment down time can difficult to quantify, and decision are based solely on repair cost which alone, if looked at closely, would justify the expense.
A detail work order system that includes all parts and labor and equipment down time is need to fully see the need.
There is a lack of hand tools for the line mechanic to properly perform basic maintenance procedures.
There is not a snap ring available for the disassembly of the sprayer flow meter which is required every 200 hours. A snap ring pliers is also used in other repairs.
The use of a common tool box has not work as there is no tool control process in place, tools are missing and damaged. A better approach would be to assign a small tool box with basic hand tools to each mechanic and then do a quarterly inspection latter it can a yearly inventory after the process is in place and each mechanic understands the responsibility.
To aid in tool inventory set in blow molded cases should be acquired the following examples would be good choices.
Screwdriver Set, Assorted Tip Style
3/8", 1/2" SAE and Metric Socket and Wrench Set
1/4" SAE and Metric Socket Set
Combo Wrench Set, 1/4-1-1/8in, 7-24mm, 32Pc
Pliers and Wrench Set, 5 pcs
Ball Pein Hammer Set, 4-Piece, Head Weight (Oz.) 8, 12, 16, 24,
One example where not having the proper tools have impacted maintence of the sprayer is the cleaning of the flow meter due at every 200 hours of operation more frequently when using powders.
The flow is the key input to the display the rate on the Multi Pro 1750 and on the larger sprays Multi Pro 5800 and input to the Pro Control computer that controls the rate.
To disassemble the flow meter to clean the rotor/magnet assembly (item 2) two retaining rings (item 5) need to be removed using a snap ring pliers which are not available in the shop currently. This type of tool can be keeped in the main tool box using an inventory control system
The line technician do not have ready access to this reference material. Speaking to supervisors the manuals are keep lock in the manager’s office so they will not be lost damaged or gotten dirty.
One solution is to have a Computer station with printer for the technicians loaded with the operator, parts and service manuals loaded on the hard drive.