ASK ERNIE: The Pros & Cons of Adding Zincs

Apparatus Maintenance Q & A

CarolinaFireJournal -

01/11/2012 -

What are the pros and cons of adding zincs to my apparatus and why aren’t they installed from the factory?

Sacrificial anodes are a long established corrective measure to slow or eliminate galvanic action within the apparatus plumbing system. Back in my day — when I was a puppy in this industry — all apparatus water tanks were made of steel and coated with some type of inner coating to prevent ‘corrosion.’ Tanks sprung leaks on an all too regular basis. Tank warranties required that the tanks be disassembled annually to restore corrosion protections and assure that none was occuring — like we were going to take the tanks apart annually, ya right, NOT. In the end, we ended up essentially with either stainless steel tanks, or poly tanks. Our specifications mandated a minimum 20 year warranty against leakage and cracking.


With that sacrificial component now gone, our galvanized pipe plumbing suffered greatly, with substantial galvanized steel plumbing being replaced annually in our fleets. We have replaced that with reinforced high pressure hoses, bronze piping, stainless steel piping, and like valving. The only sacrificial component with high fail rates is the cast iron or aluminum pump housings and components. Replacing a pump housing is extremely costly. To prevent this last component from galvanic action (electrolysis) failures, sacrificial anodes are placed in the pump housing. Any type from simple to complicated anodes with electronic notification when replacement is needed.

I use the Hale anode and drill the hex bronze portion down into the anode material using a 1/16” drill. When the anode is depleted, it will leak to the ground. Nothing fancy here. NFPA states we must remove all anodes annually for inspection and replace them as needed.

Where poly tanks are used, anode can also be specified. Usually one anode bar in each tank chamber. If this is done, make sure that you run the bonding wire from the first to the last in series and ground ONLY ONE END. Do not ground both ends, as you can create galvanic action. Water condition is of prime importance. If the water is very bad and looks a orange/brown color, it is most likely oxidized pump housing material and has a pH level off the scale. You may even be able to engage the pump and circulate a water flow with the tank suction open and the tank filler cracked and then place a digital VOM (+) probe into the tank at the fill area and the ground (-) to the batter ground and get a voltage reading.

If you can, get rid of the water, do some training exercises where you end up depleting the tank a couple of times and refill with clean hydrant water — where and when you can. Try the voltage test again and you should find zero voltage generated. That generation of voltage is the transfer of metal from some metal component into the water via galvanic action. At least monthly, flow a tank load of water on a training drill. Save the pump and extend its life.

How often should I flow my foam system as a preventative maintenance?

Both the manufacturer and NFPA 1911 state at least annually, or whenever there is a suspicion that the system is not functioning properly or following major repairs.

What are the recommended allowable amps that should be available above my amp draw for the truck? I have heard 20 percent.

Under the worst conditions, the alternator must be able to produce at least 80 percent of its rated power. As stated in NFPA 1911, 2007 Edition: 17.5.5(6): During the prescribed testing procedure of items (1) through (5), if the alternator output current does not reach at least 80 percent of its nameplate rated output current, the test has failed. If you do not have a copy of NFPA 1911, you are probably not completing proper test procedures for your apparatus. Get a copy. And, while you are at it, get a copy of NFPA 1901 (current edition) and IFSTA “Pumping Apparatus Driver/Operator Handbook, volume 2 AND IFSTA Aerial Apparatus Driver/Operator Handbook. All four are essential for the professional successful EVT.

How often should I clean and relubricate my aerial ladder?

Per manufacturer’s and NFPA recommendations, at least every 10 hours of aerial service as determined by the hour meter or sooner as atmospheric conditions dictate. Consider desert conditions where sand and airborne particles contribute to accelerated wear potential. Many choose to do the 10 hour inspection and clean/lube process monthly. Be aware that there are a number of “no lube”/”lubeless” aerial designs on the market today.

How often should I service my transmission and coolant system?

If you have a manual transmission or an automated manual (AM), follow the manufacturer’s recommendations and perform service at least annually.

Let’s address the automated transmission issue first. It is the transmission of choice in the fire service today. Allison is the most common.

In days gone by, transmission fluid was the life blood of the transmission and was changed, in total, often. If you had any of the Allisons in severe hilly conditions and it contained the internal transmission retarder, you may have been changing fluid as often as every two months in heavy and extensive usage. (Note: Dexron Fluid Specification no longer exists and is no longer licensed).

Today, Allison is warrantying the fluid in SEVERE DUTY for as long as three years, 3000 hours, or 75,000 miles, whichever comes first for any Allison utilizing 100 percent Allison “Transynd” (TES295) fluid and changing filters along with oil analysis at two years, 2000 hours, and 50,000 miles, whichever comes first.

You can now purchase TES 295 (Transmission Engineering Specification 295) from Allison, Castrol, BP (Autran Syn 295), Cognis (Emgard 2805) International/Navistar (Fleetrite Synthetic ATF), Exxon/Mobil (Movil Delvac Synthetic ATF), John Deere and Company (HD SynTran), and Volvo Truck North America (Bulldog Sythethic ATF). Note: All must carry the Allison Licensed logo and/or the “TES 295” certification.

Those transmissions that once required fluid changes every couple months or less are now successfully operating within the listed times/miles with no issues if procedures are followed. Operating temperatures drop and oil levels are extended. A resultant savings of time, money, effort and recycling of lubricants.

Next, let’s discuss the coolant. Coolant should be checked annually for quality and leaks. The radiator cap should be tested for integrity of sealing surfaces, and elastomers and pressure retention within exacting range of specified pressure of the cooling system as stipulated by the manufacturer of the chassis. Fluids should be spectrochemically inspected at the annual test. Where the fluid is out of pH range, it should be brought back into its proper concentrations and condition. It may require a complete change out. Keep it clean and keep it full to the top. It is pretty easy today to determine if there is consumption of coolant. You will find indications of multiple ‘low coolant’ data on the engine ECM readout codes. Take corrective action as indicated. Make sure air flow through the Charge Air Cooler and main cooling radiator is not inhibited by debris between the two.

What is the recommended service interval for my cooling system — most manufacturers recommend every two years?

Manufacturers recommend a cooling system service that will maintain their motor “system” in an operable condition that will not result in need for warranty claims. In our emergency services vocational apparatus, we service the apparatus, in total, as it is an internal SOP. At a maximum period time frame, we perform at least a Federal/Provincial ANNUAL safety inspection and service. When servicing the cooling system, you visually inspect the coolant, looking for an abnormal “look” to the coolant. If you suspect the fluid to be out of “specs,” take a sample for inspection using the litmus strips, and freeze protection level. At minimum, you should refresh the coolant additive package as indicated. Because of the complexity of the motor today, elastomers and dissimilar metals require pristine coolant to survive. Things like sealing rings, O-rings, hoses, radiator solder joints, and the like dictate to us that we should be sending a sample to a Spectrochemical Analysis Laboratory for professional diagnosis. What the visual test will not indicate is the overall condition of the additive package or severe contamination.

Along with the inspection and/or the replacement of the coolant, make sure you do not miss the replacement of the coolant filter. Remember, any external leak of the cooling system, where it leaves a spot of coolant on the ground, while either sitting overnight or while in operation, is considered a Class 3 leak and meets the NFPA 1911 “Out of Service” criteria. Coolant to the ground also meets the threshold of failure to meet EPA/Emissions standards. In a nutshell, if it leaks, determine the fault and repair it.

While performing the visual inspection, make sure that the radiator is properly grounded to the chassis to prevent electrolysis within the cooling system. The radiator cap must be inspected and pressure tested annually. No air should enter today’s cooling system. None. Air in the cooling system, even in the header tank, is cause for oxidation of the cooling system metal components.

Wet pump or dry pump pros and cons?

Depends. Do you run in a freeze zone? If so, you may run your pumps and all pump plumbing dry. Then, upon arrival at the scene, open the water supply from the tank to the pumping system. In extreme cold climates, any pump/tank system will be “winterized” by providing any number of anti-freeze accessories to prevent cold climate, wet pump operations. High BTU system onboard heaters, undercarriage blanket to keep engine heat moving through the chassis and up and around the pump, plumbing and tank.

Running a pump and plumbing dry in non-freezing climates is discouraged because water is a lubricant and protects elastomers (seals/packings/gaskets, etc) from drying out with a resulting loss of sealing capability. This is especially at issue if you have a dry pump that is attempted to be primed and cannot because of dry pump causation for loss of a tight system.

For this question, you must know your needs and climate. We all know that when water freezes, it expands up to 11 percent. In a confined plumbing system, this can result in pressures reaching in excess of 10,000 PSI. This is enough to be sure to fracture metal piping or pump/valve castings, a very expensive issue. Been there, done that.

What all does the new VDR record on my unit?

Before we get involved with what the VDR (Vehicle Data Recorder) actually records, let’s discuss why we have it and why it was brought into usage.

In about 1992, electronically controlled motors replaced mechanical motors. In the ECU of the motors was embedded a system of data recording that the manufacturer used to validate warranty claims. It also recorded a number of other things that could, in some cases, be downloaded in court cases. Consider that the VDR, in a more minimal level, has been around since then. In the 2009 edition of NFPA 1901 (Standard for Automotive Fire Apparatus), the provision for VDR was incorporated. Many of the operators and others look at this item as “Big Brother” invading our operation. For me, I look at it in a positive and proactive light.

This device, for me, is on-board evidence to validate and back up everything the operator and occupants of the apparatus report, following a major incident involving the apparatus. It will be your best ally when and if you are doing things to the operational consistencies of SOP and law.

Now, to the issue of what is included in the VDR:

Section 4 of 1911 states that “ALL APPARATUS must be equipped with a VDR.” By ALL, NFPA considers any fire apparatus of 10,000#GVWR or larger. The VDR must update all parameters at least once per second. The data must be stored in a 48-hour loop. The items included in the 48 hour loop are:

  • Vehicle speed in mph
  • Acceleration via Speedometer in MP/Sec.
  • Acceleration by speedometer in mph/sec.
  • Engine speed in rpm
  • Engine throttle position in percent of full throttle
  • Anti-lock brake event in on/off
  • Seat occupied states-Y/N by position
  • Seat belt status by Buckled-Y/N by position
  • Master optical warning device switch-on/off
  • Time of day on 24 hour clock
  • Date by year, month, day

It then goes on to state that the VDR must retain memory for 100 engine hours of minute-to-minute summary and overwrite data older than 100 engine hours. The 100 engine hour data to be stored shall be:

  • Maximum vehicle speed attained
  • Maximum acceleration attained
  • Maximum deceleration rate attained
  • Maximum engine RPM attained
  • Maximum throttle position percent attained
  • Anti-lock braking system event(s)
  • Seat occupied with seat belt unbuckled
  • Master optical warning device switch, time and date.

All VDR data shall be uploadable by the end user to a computer or data storage system. All data shall be password protected with access controlled by the purchaser. The apparatus shall have all necessary software to retrieve data supplied at time of apparatus delivery.

And, remember to relax — this product is your best ally.

What are the requirements for a reserve apparatus to be reserve instead of decommissioned?

From experience (remember, Ernie is old) I rely on the service life curve. In the beginning, when the apparatus is delivered, there will be a higher than normal amount of issues which we shall refer to as the “warranty period.” At one time the warranty period was universally one year. Today, the basic apparatus warranty period is recommended to be inspected at three years, due to the higher than normal fail rate of some electronic components.

Following the first wash out of the start up period, the apparatus will continue through its normal service life on a systematic routine need for service and repair. Costs will remain fairly constant. When you see the costs to maintain and repair the apparatus start to climb substantially, you can start the process of evaluation as to whether it is more pertinent to continue the repair/maintain/update the unit or to replace it as is stated as “decommissioned” in the question. Usually, the apparatus will be easily able to attain a prescribed timeline whereby it is placed into reserve status.

Reserve status is when the apparatus is used as a backup to fill in for apparatus that go in for extended service or repairs. ANY reserve apparatus MUST be maintained as any front line apparatus, because that is the service the reserve unit provides. If anything, the reserve apparatus must be checked daily to assure that it meets front line apparatus requirements. In a volunteer station that is unstaffed, that reserve apparatus MUST receive that same level of inspection and care as any front line apparatus. You just never know when it must be pressed into service. When it is required, it must perform as designed and intended.

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