Manager: Douglas R. White
Title: Director of fleet maintenance
Fleet: Dunbar Armored, Hunt Valley, MD
Operation: Largest independent armored transportation firm in U.S., operates via 65 branches to serve major banks, retailers and the Federal Reserve
Since 1923, Dunbar's armored cars — ok, trucks — have been safeguarding currency and other valuables. In this business, security is the ultimate watchword. That means zero tolerance for breakdowns.
Specially modified International 4700 straight trucks are Dunbar's vehicles of choice. The fleet consists of 1,000 of these armored cars. Under the hood, they are pretty standard — powered by International DT 466 engines with Allison automatics. Each racks up from 28,000 to 30,000 miles a year.
When a rash of engine overheating reports started coming in from the field, Doug White rounded up the usual suspects. “We thought the cause might be external, like a clogged radiator or a fan clutch failure,” he says.
“But when we really looked at what was happening, it turned out to be our cooling system maintenance was inadequate. Oil analysis detected a fairly high incidence of antifreeze leaking into the oil pan.
“The key problem was that the cooling system was not in balance. The concentration of antifreeze and additive packages in the mix was too high,” White says.
The solution began with cleaning out coolant already circulating. “First, we installed an Envirocool cleaning filter in place of the water filter on all trucks. Then we ran them for 30 to 45 days. After that, we replaced the Envirocool filter with a Penray need-release filter,” says White.
“The Penray releases additives to the coolant as needed.” White notes replacement of the supplemental Penray filter is now a PM item. “It's been estimated they will last 14 months in our service. But we've set them on an initial 12-month interval to be safe. We had had the standard water filter on a flat 12-month schedule. Engine oil is changed every 5,000 miles or 150 days, which, with oil analysis, made it possible to detect this problem early on.
“Along with removing supplemental cooling additives (SCA),” White reports, “we also took concentrated antifreeze out of our shops. We switched to fully formulated coolant. It's pre-mixed to the correct 50/50 mixture and contains all the initial SCA we need.”
White says the solution was, happily, a simple one. “Essentially, we simplified and even automated our coolant maintenance practices. Now our mechanics do not have to be chemists in order to keep the mix in the trucks right.
“It's human nature to put more in than is needed, whether antifreeze or SCA,” he adds. “No doubt that's what started getting the coolant out of balance in the first place.”
Another cool tip from White is to ditch the hydrometer. “We replaced them with refractometers, which are significantly more accurate and cover a wider temperature range.”
According to White, Dunbar is coming up on its first change cycle for the Penray need-release filters. “A lot of fleets only see the initial cost of the need-release filters, but we look at what is the cost of a breakdown — and a security issue — for us.
“Since launching this campaign,” White adds, “we've gone from three or four overheats a month to just two isolated ones, both of which we were able to attribute to a specific problem at one branch.”
Maintenance Bay presents case studies detailing how fleets resolve maintenance-related issues in their own facilities