They call it “Paradise.” Then, in the next breath, they call it “The Gateway to Hell.” How else would you describe Pahrump, NV? The city of Pahrump, pop. 33,000, can warm up to well over 100 degrees on a summer afternoon, and it borders California’s Death Valley National Monument, the final resting place of many an overheated vehicle. And yet, on the sunny, 55 degree February morning I visited the offices of Pahrump Valley Fire & Rescue, it sure felt like paradise.
Extremes typify Pahrump, and make the care and maintenance of the fire & rescue fleet a daily challenge for fleet manager John O’Brien.
“We can see a diurnal temperature change of 90 degrees in a day,” he says. “The coldest we get is -10 to -15 below, and our highest temperature recorded was 125 degrees.”
HOT & HEAVY
O’Brien oversees spec’ing and maintenance of a fleet of 45 vehicles stationed at four locations in the Pahrump Valley. The coverage area goes from 312 ft. below sea level all the way up to 8000 ft. above, and, yes, it includes the vast, barren expanses of hell, otherwise known as Death Valley. “Resources are spread thin,” he says. “It could take us up to three or four hours to respond to a call. We get calls up in the mountains that can take us two hours to locate”
The service handles approximately 8,000 emergency calls a year, and tallies up over a million miles annually. And there’s no excuse if a truck has a heat-related failure.
“There are months during the summertime, with the extreme heat, when I may have two, three of four ambulances down in one day,” O’Brien says. “You’re scrambling to put pieces back into your fleet, because you’ve still got to take your calls and provide the same level of service and coverage, but you don’t have the vehicles.
And it’s not just the heat. Although most of the city’s roads have been paved or coated for the past ten years, much of the service area can only be traversed on dusty dirt roads. “We still have a lot of issues with dust,” O’Brien says. “Dust is a big issue on our serpentines, our belt tensioners, because of the high silicon content. We’re seeing a lot of wear issues.”
SYSTEM BREAKDOWNS
The heat affects trucks in a lot of ways, but the brakes can be the first to suffer. O’Brien recalls a pair of custom-built trucks that were coming in for brake jobs every 2,000 miles. That’s bad enough from a maintenance standpoint, but the safety factor was even more alarming:
“One day one of the guys was headed to an accident in one of these vehicles, and he goes to take the corner, and he can’t stop,” O’Brien recalls. “He had overheated the brakes making brake applications up to that point,” and that was the end of his call.
“Again, you have to remember the temperature on the pavement: we could be at 165 degrees coming up from the pavement in radiant heat,” he explains. “You add that to the brakes, you add that to the tire, you add that to the powertrain and you’re cooking everything, and it doesn’t have a chance to cool off.”
O’Brien’s solution was to have retarders installed on his bigger trucks. “That’s the only way we stop these big vehicles, because after so many brake applications we start to see brake fade.
“We’ve looked at everything clear down to the foundation of our brakes,” he says. “We looked at the capacity. We looked at S-cams. We looked at the length of throw. We looked at the entire system.
“When we compare a six-inch slack adjuster to a six-and-a-half, we’re increasing the amount of brake pressure with the six-and-a-half, because we’ve got more leverage,” he says. “We also have to look at surface area and surface cooling. We have to look at venting. We’ve even looked at hardening with liquid nitrogen, and we actually get better life on our rotors when we harden them. We need to be creative, and we need to look at all the possibilities.
“You can’t have failures in the emergency vehicle industry, so what you do is, you start PM programs prior to failures,” O’Brien explains. “So, we started seeing starters would last about 120,000 miles. Alternators, we were getting about 60,000 miles before failure.
“But, some of our early alternator failures were due to people not following procedures,” he admits. “If you put all your emergency lights on, you’re looking at a very high amperage drop. The older lighting systems might draw anywhere from 150 to 200 amps. You add a 1,000 watt converter and you’re drawing another 100 amps off. Well, with a two alternator system you’ve maxed out at 230 amps-times-two system. With 400 plus degrees under the hood in the summertime, you cannot charge your batteries. So we implemented a system: we had our idlers set at 1,500 to 1,750 rpm. This gave us the maximum output on our fan systems drawing air through the radiator, which gave us the most cooling we could have.”
GETTING CREATIVE
Sometimes beating the heat calls for creative thinking. Such a case came up when underhood temperatures in O’Brien’s Ford E-Series ambulances started causing serious electrical problems.
“We had to put complete new looms in them because we were literally baking and melting the wires together inside the looms,” O’Brien says. “When you start melting and compromising the wiring, you start to get engine shorts and electronic failures on your mission components. We were wrapping all the engine looms on the E-Series in asbestos, then we had to put metal clamps around them to keep the asbestos on them, and that was the only way we kept the harnesses from burning.”
O’Brien’s creative solution? If you can’t change the truck, change trucks. He replaced his E-Series Fords with F-Series trucks, in order to get more underhood space and more cooling under the hood.
“We still see temperatures up at 300 to 350 degrees with the F-Series, but that’s a far cry from 425 degrees melting plastic underneath an E-Series,” he says.
Charging batteries in extreme heat calls for even greater creativity.
“Now, obviously we don’t get very good battery life if the batteries are under the hood at 400 degrees,” O’Brien says, “because all that electrolyte is sitting there boiling and it’s constantly gassing. You put blankets around them and it doesn’t do any good; it just saturates those blankets with acid and then you end up with corrosion under the hood, issues with battery cables and connections.”
O’Brien’s solution is to compartmentalize batteries away from the engine and heat sources. Many of his vehicles have batteries in extra locations: they might be behind the driver or passenger, or they might be under the vehicle on the frame out.
“Underneath the vehicle is not going to be a good choice, especially if you have to sit there idling the vehicle,” he says. “We don’t have a choice. Our trucks are going to be idling—we can’t shut them off.
“All of our vehicles have battery chargers on them with shore lines. When our vehicles leave their batteries are fully charged with a variable-voltage charger-conditioner that sits there and doesn’t make a battery with a memory. Yeah, you’re going to spend a lot of money on a charger-conditioner, but the reliability of your vehicle and your battery life depends on it.”
SURVIVAL INSTINCT
After many years of keeping vehicles running in the Nevada desert, O’Brien seems to have developed a strong survival instinct. If there’s a vehicle system that’s adversely affected by heat, he’s figured out an adaptation.
Remember that diurnal temperature shift of 90 degrees in a 24-hour period? Well, guess what that can do to tires. Tire air pressure can change dramatically from night to day, wreaking havoc with tire life and ride quality.
O’Brien’s solution? If you can’t change the air, change the gas.
“Nitrogen-filled tires—my God, why didn’t we start looking at that years ago?” he exclaims.
“Nitrogen is saving us money,” he goes on. “Some of our fleet has nitrogen in the tires now, and we’re talking about 100 percent fleet on nitrogen fill down the road. With the high temperature fluctuations, the diurnal temperature changes, we could gain up to 40 pounds of tire pressure just from heat. When you’ve got a tire that’s supposed to have 80 psi and suddenly it’s got 120 psi in it, you’ve got the driver complaining about the vehicle’s rough handling, you’ve got tire wear issues. It’s extremely hard on the tire, and that’s dangerous.”
With nitrogen tire inflation, O’Brien is not seeing those extreme differences in tire pressure, so he can keep the tires closer to the manufacturer’s spec’s. As a result, tire failures, such as belt separations, have gone down.
MOVING AIR
To O’Brien, managing heat is all about moving air. If you can keep the air moving over and around the engine and drivetrain, constantly carrying that heat away, you might—might—keep your truck functioning in the desert heat of the Pahrump Valley.
“All that underhood heat, all that undercarriage heat, has to be moved,” O’Brien explains. “So, we’re looking at those tighter radiator assemblies and we’re pushing the air past the engine in large volumes and dispersing that air around the vehicle, not under the vehicle. And on a fire truck, it’s made worse by the fact that you’ve got the engine and transmission compacted together.
“You have to move that air past that engine,” he says. “If you don’t, you’re going to have EGR failures, turbo failures, you’re going to see the ceramics in those turbos disintegrate from the heat, you’re going to see poor performance and those engines aren’t going to be reliable.”
O’Brien is disappointed that he is only getting two years out of a radiator, and the press-on plastic tanks are melting. and starting to leak. To make matters worse, electric fan clutches are failing as well, so the cooling system can’t even keep up.
“We have looked at everything,” O’Brien says. “Cooling system capacities, extra coolant jugs, extra oil filters, extra oil coolers, looking at the grades of our oils and the oil change intervals. Most vehicles have oil changes of 3,000 to 5,000 miles at a maximum. We use parasynthetic oils; all of our rear ends are 100 percent synthetic, all of our hydraulic fluid and transmission fluids are 100 percent synthetic.
“We have found that by running synthetic fluids we get better life, we get better fuel mileage,” he says.
CREATIVE SPEC’ING & DESIGN
O’Brien seems to enjoy the challenge of spec’ing vehicles that can handle the unique demands presented by operating in the Pahrump Valley, even when that seems almost impossible.
Disappointed with his recent Ford diesels, for example, O’Brien has started to spec’ Dodge replacements. He is about to take delivery on a trio of new Dodge ambulances, but his efforts to spec’ a Dodge pickup to tow his hazmat trailer have hit a speed bump.
“It’s that thing every fleet manager goes through: what’s going to be the right vehicle for your fleet?” he asks. “What’s going to be the right option? You have to weigh the costs out.
“The last vehicle we got done spec’ing, we couldn’t buy it—it cost too much!” he says. “We just got done spec’ing a Dodge 3500 pickup truck, with four wheel drive, a trailer towing package, winch, full lighting package, and we blew our budget by $20,000. We’ll have to go back out to bid and take off some features. We’ll still order the vehicle, because we need it in the fleet, but I won’t get all the features I want. We may have to look at a lighter axle; I hope not, because I need that unit to tow the hazmat trailer.”
OUTSOURCING FROM 350 MILES AWAY
O’Brien used to maintain Pahrump’s fleet in-house, until an accident on an emergency call put him on the disabled list and he was forced to outsource.
Now, his vehicles are serviced at an assortment of dealerships and independent shops, many of them right in the neighborhood. Of course, in this case the neighborhood is Las Vegas, some 70 miles away. More specialized work can neccessitate a 350-mile drive to the American LaFrance service center in Los Angeles. Simple oil changes can be done in Pahrump, and the fleet’s new Dodge ambulances will be serviced at Pahrump’s Dodge dealer shop.
“It’s not uncommon for us to jump in, take two vehicles—we have a chase vehicle—350 miles to LA, drop the vehicle off for PM, drive back, then go back to LA to pick the vehicle up after two or three days, a week, a month, however long it takes to get the repair work done,” he explains. “We do a lot of service in Las Vegas: the International dealer has done work for us for years, we use Freightliner, I’ve got a frame-straightening shop right down the street from Freightliner.
“It’s very hard to find competent technicians out there when you go outside, and when you lose the advantage of in-house then you’ve got all those transportation costs and you’ve got a logistics issue.”
An ASE and EVT Master Technician himself, O’Brien knows that not just anyone can repair a fire truck or an ambulance, and he has passed over a lot of shops that have wanted his business.
“When you utilize outside sources, you have to look at their competency,” he says. “Not everybody can work on a fire truck. Not everybody can work on an ambulance. A lot of technicians don’t want to, because they can’t make the same money on it; it’s a different system. The trucks aren’t put together the same way; they have a lot more peripherals, hoses and other things that are in the way. It’s a serious issue.
“I have gone to places for a brake job and asked how they bleed the brakes. ‘Well, we just gravity bleed them.’ Well, that’s not acceptable,” O’Brien insists. “ABS systems need to be vacuum bled, or pressure bled on certain systems. And you have to be careful, because some systems say ‘apply no pressure to the master cylinder.’ Some systems say ‘do not flow any fluid from that wheel back through the ABS controller back up to the master; you will damage the system.’ They mean it: that could be a $2,000 ABS controller with an accumulator on it!”
In other words, not something you want to leave to an unproven shop...
STUMPED?
O’Brien amuses himself by watching the OEMs bring test trucks right past his front door for testing in Death Valley, and then haul their dead carcasses back out when they succumb to the heat.
But it is a reminder that not all trucks survive, not all heat-related problems can be solved, and in fact there is one heat-related maintenance issue that has stumped O’Brien: the turbos and coolers on EGR-equipped engines.
“We’re seeing EGR and EGR cooler failures because of the high temperatures,” he says. “We’re seeing turbo failures because of the high temperatures. Charge air coolers are very important; vehicles not equipped with charge air coolers just can’t survive in this climate. So, we’re seeing rapid turbo failures, oil leaks, we’re even seeing charge air coolers completely full of crap.”
But O’Brien has a way of making today’s problem turn into tomorrow’s ingenious adaptation, so those EGR problems may not always be an issue. For all the heat in Pahrump Valley, O’Brien is remarkably cool about his situation.
“I’m an old fart, but I have to keep up with the changes in the industry,” he says. “If I don’t, I’m not going to be any good.”
