Service Tip Archive




Diesel Fuel and Additives SI98-3

Clean Air Regulations have complicated what used to be very basic. Before the regulations, you choose number 2 diesel for summer use and blended fuel for the winter. Now you have to chose between Low sulfur fuel for highway use or regular fuel for off road use.

The process for reducing the sulfur level in fuel also reduces the lubricity of the fuel which can cause internal parts of the fuel injection system to wear at a faster rate than will occur with off highway fuel. The sulfur in the fuel also acted as a natural anti-oxidant. The removal of the sulfur can lead to gum and deposit formation in the system components.

To combat the above mentioned problems, John Deere recommends the use of diesel fuel conditioners when using highway fuel in your off road equipment.

John Deere has specifically designed two fuel conditioner formulations. Use of the summer formulation will improve diesel fuel quality and maintain peak engine efficiency. Regular use will minimize many of the problems caused by impurities in diesel fuels. The winter formulation affords all the benefits of the summer additive, plus provides fuel flow improvers to reduce fuel gelling.

The practice of cutting number two fuel with number one fuel or with kerosene is in my opinion your best insurance to prevent fuel gelling. The place in the world the fuel comes from has an effect on how well anti-gel additives work. Some of the fuel we get in this area is from Alaska and is not very responsive and must be cut with lighter fuel. Be certain to discuss with your fuel suppliers your winter fuel needs when ordering fuel in the fall or winter.



Sprayer CalibrationSI01-1

No-math ATV Sprayer Calibration Document

What is Sprayer Calibration?
Sprayer Calibration is the process of determining if your sprayer is producing the desired results. By results, we mean, are you applying the correct gallons per minute of chemical/water mix and are you applying it into the proper areas of the crop? Calibration is also the procedure of choosing the correct nozzles for your application.

How do you check Calibration?
One of the easiest ways to test the gallons per minute (GPM) that your sprayer is putting out, is to fill the sprayer to the top of the center tube or some other indicator in the tank. Then with the sprayer running at operating RPM and pressure, open the spray boom valves for exactly one minute. Next, with a bucket that is marked with gallons and quarts levels, bail water back into the tank until it is filled to the previous filled level. The amount that you bailed back is the GPM that went out the nozzles. Compare this amount with the calibration sheets used when the nozzles had been installed originally. The nozzles should be replaced if the actual GPM is greater than the desired GPM by 5% or more. While the pressure of the sprayer can be adjusted to compensate, I do not advise it because the pattern on weed sprayers deteriorates rapidly as wear increases. On air blast sprayers, the nozzle sizes vary. The wear does not happen equally to the different sizes, causing the original pattern to fail. If your actual GPM is less than the desired GPM, look for plugged boom strainers or restricted hoses between the boom control valves and the booms.

Important Calibration Formulas for...

Air Sprayers:

GPM (for one side) = GPA x MPH x Row Width (ft)

GPA = GPM (for one side) x 990

MPH = GPM (for one side) x 990
             GPA x Row Width (ft)

To Determine actual MPH of your tractor:

MPH =                      120                       
          number of seconds to travel 176 ft

or MPH = Distance Traveled (ft) x 60
                  Time (seconds) x 88

GPM = Gallons per Minute
GPA = Gallons per Acre
MPH = Miles per Hour (at operating rpms)

Weed Sprayers:

GPM = GPA x MPH x Width (ft)

GPM = GPA x MPH x Width (inches)

GPA = GPM x 495
MPH x Width (ft)

GPA =       GPM x 5940       
          MPH x Width (inches)

MPH =    GPM x 495    
          GPA x Width (ft)

MPH =        GPM x 5940      
          GPA x Width (inches)

Computer Calibrations
We provide, as a free service to our customers, computer generated calibrations for their air blast orchard sprayers that use Spraying Systems or FMC nozzles. Just call myself or our Parts Department for this service. When you call us, we will need to know the following facts in order to provide you with an accurate computer calibration: Your speed in MPH, your desired application rate in GPA, the number and type of nozzles, the width of the tree row, and the pressure (if it is not adjustable). We should also know the size of the trees. The more accurate your facts are, the more accurate our calibration will be. If you have different row widths, we can usually vary the pressure and/or the speed so you will not have to change any nozzles when changing orchard blocks.

Calibration Tips

  • When calibration weed sprayers, use the nozzle spacing for width
  • Nozzle placement on an air sprayer boom will typically have 70% of the material going out the nozzles in the 1:30 to 3:30 position with the balance split between top and bottom
  • Follow the sprayer manufacturers operator manual recommendations
  • Always test your new calibrations as explained above at the beginning of this report
  • Weed sprayer calibrations can easily be checked by collecting spray into a container for one minute and measuring it accurately.
  • You can easily determine if full pressure is getting to the spray boom by fitting a gauge in place of one of the smallest nozzles. Use this test when you find you still have material left in the tank when it should be empty.
  • When you experience low pressure problems, always check to see if bypass water is still returning to the tank. This will tell you if you have pressure control problems or if the problem is with the pump, the suction system, or somewhere else. Testing your calibration as described at the beginning of this report will determine if perhaps the nozzles have worn too badly.



Heavy Duty Antifreeze SI98-1

Are you using the right antifreeze for your equipment? All antifreeze is the same isn't it? No they are not the same. All will prevent freezing, but many do not perform adequately in heavy-duty engines. They do not contain the additive to prevent cylinder liner cavitation and some may cause gelling if too much of the additive is put in them.

Cylinder liner cavitation or erosion is caused when small bubbles form and implode and take away minute parts of the liner or cylinder block in the process. An additive can be put in to prevent this. It causes the coolant to be slicker and to stay with the liner better when the piston changes direction at the bottom of the stroke. The additive needs to be put in at 1 oz per quart of capacity on initial charge and 1/2 oz every 6 months. We sell kits to test the level to be more accurate.

The normal rust inhibitors and additives in new antifreeze are expected to last two years and be changed. Automotive antifreezes contain silicates (grinding compounds) to remove corrosion from aluminum parts in the systems. Changing the antifreeze every two years removes the particulate matter from the systems.

John Deere has made all of this simpler. They now make pre-diluted heavy-duty antifreeze. It is pre-diluted with distilled water and already contains the anti-cavitation additive already in it. By being formulated with extended use additives and distilled water, it only needs to be changed every 5 years if system has been topped off only with pre-dilute JD antifreeze. It is also recommended for automotive use.

Some people argue it is too expensive and do not want to buy water. If you add up the cost to change regular antifreeze ever two years and add the costs of the liner anti-cavitation additive, it becomes a very good buy. For these reasons, it is the only antifreeze we install in our service department when we are working on your diesel engines.



Air Conditioning Retrofitting SI98-2

Are you confused about your air conditioning options with R12 "FREON" being discontinued?

It is not as complicated as some would lead you to believe. R12 manufacture in the United States is not legal and supplies are diminishing as was the "plan" in the Clean Air Act. Because of taxing and raising costs, the supply is still adequate, though very expensive. Most repair services are receiving about $65.00 per pound for it. Cab air conditioning systems hold up to 5 pounds of refrigerant.

The options you have when a system malfunctions are:

  • A: Open the windows and do nothing. This is least expensive, but not very comfortable or desirable.
  • B: Repair cause of not working and recharge with R12. Depending on required repairs, may be less expensive and will work very well. Down side is risk of losing refrigerant again from leaks or relief valve discharges caused by plugged condensers. If compressor has failed will be more expensive than to retrofit.
  • C: Repair system and retrofit to environment friendly R134a. This is the option we recommend. Systems work nearly as well as with R12. R134a sells for $7.84 a pound which greatly reduces costs of having systems recharged.
  • D: Repair system and recharge using one of the other so called "R12 Drop-ins". We strongly discourage use of these. Some are flammable and by law an installer must have separate reclaiming equipment for each type of refrigerant installed. This may make it difficult to find someone to perform repairs to the unit in the future.

As mentioned on option C, HFEC recommends retrofitting to R134a whenever possible. There is a lot of misinformation circulating about retrofitting. Compressors and hoses do not need to be replaced unless have failed. All that must be done is to remove compressor and remove as much mineral oil as possible and replace the receiver dryer. We also recommend replacing the thermo-expansion valve, as it will have to operate in a different position than it did with R12 and they lose their effectiveness with time anyway. We replace the mineral oil with Ester oil which is compatible with R12, R134, Pag and mineral oils. We have successfully retrofitted the following units: JD 4230, 4840, 2950's, 2280, Heston Swather, IH Swather, Timberjacks, Chevrolet PU, Ford 7710 and my own 85 Chevrolet Celebrity. We have equipped our service truck so repairs can be made in the field as well as the shop. We carry a large selection of hose fittings and a hose press so most hose failures can be repaired on the spot.



Slip Clutches and Torque Limiter Maintenance SI 99-1

A slip clutch and a torque limiter are the same thing and will be referred to in this report as a slip clutch. The function is to protect the implement and the tractor from excessive forces caused by sudden changes in the load. This often happens when the PTO is rapidly engaged manually or hydraulically by the operator having the engine running at high RPM. Other times a slip clutch may slip is when the implement is forced into a heavier load than it was designed to handle, which is normal.

For years asbestos was the primary material used for clutch and brake lining material. Asbestos wore well, was resistant to damage from heat and did not absorb moisture. Asbestos fibers have since been determined to be carcinogenic, causing it to be outlawed for use in most applications. Substitute materials have been developed that work well in clutches. Their drawback has been most will draw moisture. The moisture will cause the disks to rust and stick to the steel plates, locking the slip clutch solid, as if it were not in the drive train resulting in damage to components.

To prevent damage to your machines, slip clutch maintenance is critical, especially when the machine is first used after winter storage. Refer to your owner's manual for the procedures. Basically, service amounts to loosening the clutch and then slipping it until warm enough you don't want to hold onto it, and then resetting the spring tension. If you measure spring length before loosening, you have a place to return to. Bush Hog, one of the largest manufacture's of Rotary Cutters, specify the above procedure be followed whenever a cutter is left idle more than 30 days.

In the past five years, we have received bulletins from all of our suppliers stating warranty will not cover damages resulting from improper slip clutch maintenance.

Slip clutch maintenance can easily be overlooked, but can be very costly if you do. Please call or stop by if you need assistance. Through John Deere we have access to a universal replacement clutch for most machines.