Fleet Maintenance Tips

Proper lubricants and coolants are more critical now than ever before.

Fleet Maintenance Tips
By: John Bellah

The NextGen police vehicles from Chevy, Dodge and Ford may require less overall maintenance due to longer engine oil change intervals, fewer trans fluid flushes, and no spark plug changes. However, they are more sophisticated, and very sensitive to upfit and maintenance procedures. They are definitely less tolerant unapproved lubricants and coolants.

In most cases, the 3,000-mile engine oil change interval is a thing of the past, given today’s advanced engine technology and superior lubricants. With some vehicles, such as General Motors and Chrysler vehicles, the engine computer calculates when the engine oil should be changed. This figure is calculated, based on the engine speeds and oil temperatures during those operating times.

There are exceptions to every rule, such as the engine oil being drained prematurely for repair work or after operation under adverse conditions—such as severe dust. Another scenario is if the oil-drain lamp is accidently reset. In those cases, GM advises to drain at 3,000 miles and to reset the oil drain light. When the oil change light comes on, the vehicle can be safely operated for another 600 miles before the old oil is drained, but not to exceed that mileage. For those who don’t believe in computer-suggested oil changes, remember the manufacturers are the ones who warranty their vehicles in most cases for five years or 100,000 miles.

The San Francisco Police Department is one agency who deviates from the longer service intervals and still strictly adheres to 3,000-mile oil change intervals on marked police vehicles and 4,000 miles for unmarked and administrative vehicles. This figure is tracked by their vehicle maintenance software. When the vehicle is brought in for fueling if a service is due, the car is immediately pulled out of service.

Some may argue their vehicles are over-maintained; however, according to Sergeant Richard Lee, SFPD fleet manager, these mileage figures are appropriate as brakes and suspension components take a beating in their hilly environment. Shop space is at a premium in that crowded city, and at those intervals, brake pads will probably need replacement. The bottom line is vehicle maintenance should be tailored to the operating environment.

Different Engine Oil Required

The days of stocking Delco 15W-40 engine oil, Dextron ATF, and green coolant for your entire fleet are long over. Today’s manufacturers now require specific coolants and lubricants for best performance and to keep the warranty in effect.

One example is the Dodge Charger. Versions with the 5.7L HEMI® require 5W-20 engine oil, whereas the older 3.5L V-6 engine requires 5W-30 oil. Using the wrong weight engine oil, such as 10W-30, in the 5.7L will affect the Multiple Displacement System (MDS), which is partial throttle cylinder deactivation. This will trigger a Diagnostic Trouble Code (DTC), that infamous “Check Engine” light.

Mixing coolant types is another no-no as the long-life orange (Dexcool®) used in GM cars is not compatible with the traditional green coolant. Mixing these types of coolant can cause serious corrosion issues. All three makes of police vehicle have engine coolant unique to that make.

Trans Fluid

Likewise for the five-speed automatic transmission in the Charger, which requires ATF+4 fluid. If in doubt, check the container, which should be labeled as meeting Chrysler’s MS9602 standards. Using Dextron fluid in these transmissions will cause clutch chatter in hotter operating conditions. Again, the trans fluid required for all three makes of police vehicles is different and not interchangeable.

Several manufacturers, including Ford, no longer have drain plugs in their torque converters, making it a difficult and messy proposition to service an automatic transmission as much of the old fluid is trapped in the converter. One reason for omitting the drain plug is cost. The other is manufacturers are encouraging the use of transmission-flushing machines.

The City of Topeka, Kans. has used fluid exchange units for several years, and report excellent results. Their maintenance schedule requires routine changes of automatic transmission oil, power steering fluid, and engine coolant. According to Brian Brigenwalt, Fleet Service Manager, they utilize a Wynn’s Tran Serve® machine, to service automatic transmissions every 30,000 miles. Engine coolant is also changed at this interval.

At every other transmission service (60,000 miles), his shop personnel will drop the pan and replace the filter. Also at this mileage, power steering and differential fluids are also changed and the fuel injectors are cleaned. Brigenwalt, and his predecessor, Ron Raines, report markedly fewer premature transmission failures after utilizing these transmission service procedures; however, they caution regardless of maintenance, the life of a CVPI transmission is limited to about 100,000 miles in police service.

On the other side of the coin, Chrysler recently issued TSB #D-12-24, which addresses the routine practice of engine, transmission, power steering, and air conditioning system flushing, which are strongly advocated by various “quick-lube” operations. Chrysler’s position is these components do not normally need to be flushed. The exception to this would be if or when a component failed. Then housings, hoses and coolers should be flushed prior to re-assembly.

Trans Flush

Not all fleet maintenance facilities can afford a fluid flushing machine, and Mike Bruno, a police mechanic for the Highland Park (Ill.) Police Department came up with a cost-effective method of completely changing fluids in their later Crown Vics. This process utilizes a 5-gallon bucket, hose clamp, and 6 feet of plastic tubing. The cooling line from the transmission is disconnected at the cooler and the length of plastic tubing is secured to the disconnected line with the hose clamp, the other end of the tube being placed in the bucket.

Remove the dipstick and insert a funnel into the fill tube. Start the engine and slowly add 12 quarts of A.T.F. into the trans—at about the rate the old fluid is coming out. When fresh fluid starts coming out of the hose, the old fluid has been purged. Stop the engine and reconnect the cooler line to the cooler, add enough A.T.F. to top off the trans, check for leaks, and road-test.

For additional insurance, they install Ford’s in-line filter (P/N #XC3Z-7B155-CA). This filter is really a rebadged Magnefine unit, which contains a 35-micron filter and a magnet to help trap ferrous matter sloughed off from the planetary gears along with other trash, which was not trapped by the filter in the pan.

Full Synthetic

The City of La Habra, Calif. used to average about 65,000 miles before transmission failure occurred on their police vehicles, even though they received the recommended transmission service every 30,000 miles. Mark Compton, the city’s fleet manager, switched to a full-synthetic ATF (Dextron VI) that lengthened trans life an additional 30,000 miles. With the upgraded oil, transmission life is now extended toward the 100,000-mile mark. If major transmission problems do occur, La Habra Fleet Services will exchange the offending unit with a genuine Ford remanufactured unit, which has all the latest upgrades and is backed by the factory warranty.

Many of our newer transmissions do not have dipsticks, thus the computer monitors the fluid level. Servicing these newer transmissions now require a scan-tool, a subtle reminder that transmission servicing should be conducted by a properly trained technician.

Paul Condran, Equipment Maintenance Manager for Culver City, Calif. is an advocate of Pure-Power Oil Filters. (www.gopurepower.com). These reusable filters can be disassembled, cleaned using a parts washer or by hot, soapy water and reused, lasting the lifetime of the vehicle. The manufacturer claims better oil filtration, increased oil pressure, and longer engine life. Using Pure-Power filters also greatly reduces the environmental issues of disposing of conventional filter packs.

Condran stated the initial cost of the Pure-Power units is realized after just six Preventative Maintenance operations, and by having the drain oil analyzed, has settled on 8,000-mile service intervals for police vehicles.

Reclaimed Oil?

Many fleets today use re-refined engine oil. Today’s re-refined oil differs vastly from the “reclaimed” oil of yesterday and meets or exceeds the same high standards of “virgin” oil. While the cost difference between “virgin” and re-refined oil is negligible, the use of re-refined oil is used by numerous major fleets and is another step in going “green,” by saving our natural resources.

Many major refineries offer re-refined oil and it can be handled in two ways—oil purchased from the open market, or the “closed-loop” process where the drain oil from individual fleets can be re-refined and recycled back to that fleet. When re-refined oil is processed, water, sludge, and other contaminates are filtered out and the appropriate additive packages are added. Oil that meets American Petroleum Institute (API) standards will not void vehicle manufacturers’ warranties.

Tires and Wheels
T. J. Tennant of Bridgestone-Firestone related that operating tires that are 20 percent underinflated (only 7-p.s.i) will eventually cause permanent damage to the tire due to heat build-up. He strongly advocates periodic checking of tire pressures—abiding strictly by the factory-recommended tire pressures.

There is also considerable controversy regarding repairing tires on emergency vehicles, with the combination plug/patch repair method being the only approved tire repair method according to Bridgestone-Firestone. Today, however, many fleet administrators will simply remove the damaged tire on an emergency vehicle, and replace it with a new one—period. If the damaged tire is repairable, it would be placed on a detective or admin vehicle after repair.

Proper tightening of wheel lugs is vitally important—for safety reasons and to prolong brake rotor life. It should be standard procedure to tighten lug nuts in gradual steps, using a star pattern and then properly torque the wheel to specs. The apprentice mechanic at the outside repair facility—a tire store or repair shop, may not be aware of these issues and in one pass, snug everything down in a circular pattern with an impact wrench—and on to the next vehicle—causing vibration and rotor issues.

Keep in mind, the torque specs on a police vehicle may differ from that on the civilian counterpart. Retail Dodge Chargers only require their wheels to be torqued to 110 foot-pounds, while the police package versions specify 140 foot-pounds. The same goes for certain suspension components.

Spark Plugs

Many of today’s engines have aluminum cylinder heads and the longer life spark plugs can make plug changing a challenge if the plugs have been in the engine for thousands of miles. Spark plugs are made of steel and when installed in aluminum heads, over time, galling may occur due to the different expansion rates of the different metals. Carbon build-up can also aggravate the problem, causing the aluminum threads to strip during plug changes. This can be an aggravating, time-consuming, and expensive proposition to repair.

It is recommended on engines with aluminum heads, that plugs never be removed from a hot engine and savvy techs will let the vehicle sit overnight before attempting a plug change. Prior to removing plugs, the plug wells should be thoroughly blown out with compressed air to ensure no grit will sneak into the cylinders. Another trick is to fill the plug well with penetrating oil, such as PB Blaster® to help break loose any rust and accumulated carbon deposits prior to removing the plugs, and allow the oil to seep in. Remove the old plugs in ¼ turn steps to allow the penetrant to reach the bottom threads, and minimize galling and stripping.

The jury is out on using anti-seize compound when reinstalling the plugs. Some manufacturers strongly recommend using OE plugs as an anti-seize compound as part of the plug’s external plating, and adding anti-seize, when it is not recommended may result in erroneous torque readings, allowing the plug to be over-torqued. Needless to say, plugs should be properly tightened to manufacturers’ specifications to prevent stripping or blowing out.

If a plug strips out, there are various methods of repair. Ford requires head removal if it is a warranty issue. There are some kits available—both by Ford and by outside suppliers, which allow the stripped thread to be repaired while the head is still attached on the engine. Some words of caution: Some repair kits use stainless-steel inserts while others are aluminum. Using a stainless-steel insert in an aluminum head will change the spark plug heat-dissipation characteristics, which can lead to detonation (pinging) inside that cylinder—and possible engine damage.

John Bellah is technical editor for Police Fleet Manager and is also a member of SAE International. He is a retired corporal for the California State University, Long Beach Police Department. Prior to entering law enforcement, Bellah worked for several years as a mechanic/technician at various dealerships in the Southern California area.

Published in Police Fleet Manager, Jan/Feb 2013

Rating : Not Yet Rated



No Comments

Close ...