Believe or not, there is a lot in common with the chassis of a fire apparatus and the different components that have fluid in them. We will discuss in this article what to check for when inspecting and visualizing the apparatus chassis and the different fluid checks necessary for your daily, weekly and monthly inspections.
Anyone viewing a fire apparatus being fabricated at the factory would better understand how the different components get attached to the truck.
The foundation of the vehicle starts at the frame rails, the large, long, box-shaped pieces of metal. They run from the front to back of the apparatus. Subsequently, the axles, suspension, wheels and tires are attached. Now we have what is called a "rolling chassis."
What occurs next is the assembly of the engine and its components, transmission and drive train, steering components, power steering box, air or hydraulic brake components. If the vehicle is going to have a pump, the components would then get installed for ladder or aerial devices. Final stages would include the cab and body with compartments and anything else above that.
The point here is that we are working from the ground up. Also, we are now seeing the many components that are attached to the chassis. Many components have various fluids — power steering fluid, gasoline or diesel fuel, transmission fluid, hydraulic fluid, engine coolant, water (from the pump or tank) and the recent addition of diesel exhaust fluid (DEF) or Urea additive.
A key responsibility is keeping your chassis clean. Besides cosmetics, it allows us to inspect the different components, whether it be suspension or linkages or any other item for any damage (and most importantly, to see if there are any leaks).
When the chassis is dirty and full of road grime, grease or any other debris, it makes it difficult to see if a fluid leak is occurring. This is due to the dark color of the dirt that masks the various colors of the fluids. Plus it tends to absorb the fluid, making it difficult to notice.
Granted, there is a certain amount of "normal" seepage that occurs over time around certain components — for example, the oil pan (gasket) or transmission (gaskets). If it is a true leak, remember that they don't get better over time and you will notice it worsening with regular inspections.
Below is a visual of a hydraulic leak that occurred on an aerial/quint apparatus. It will give you a great idea of how important it is to check your chassis and note any fluids leaking. This leak had gone on for some time without being noticed until a component failed. Thank goodness it was during a training exercise and no one was affected or injured.
Nowadays, many newer fire apparatus have many diagnostics on them for fluid checks via on-board computers. In my opinion, they should not replace the old reliable "dipstick."
If your apparatus does not have the dipsticks or manual fluid checks specified in the manufacturing of the truck, I would have it put into the build to assure the truck is delivered with them. Have an access hatch placed to your liking, so you can have access to these fluid checks. Manufacturers usually locate the hatch on the engine cowling/cover or "dog house" in front of crew seating in the back cab.
As with any type of fluid checks, it is highly recommended that some sort of nonporous latex glove or mechanics glove be worn to avoid harm to the skin. As far a checking the actual fluids, there is a lot that can be explained by touch, appearance or smell.
Car shows on TV, especially dealing with repairing antiques and classics, emphasize smelling the fluid. A lot can be revealed by the odor (e.g., if it is old or new, running too rich or lean, etc.).
Visually, much also can be noticed. Any type of milky, opaque appearance is usually indicative of water infiltration. This is never a good sign. It should not be in the oil or transmission fluids.
Feel is also important. Fluids should never feel gritty or contain metal shavings. This indicates some type of component or part failure or deterioration. Clear fluids can either be water or hydraulic fluid. The best way to tell is by feeling it for its viscosity.
Remember, some water fluid on the floor may be normal if it is from the drain of the air conditioning due to removal of the humidity/moisture/condensation inside the cab. But it can also mean that you have a leaking pump or pump packing, which is undesirable. The location of the water leak will dictate the component with the leak.
An easy, common-sense way to tell if there is fluid leaking is to view the apparatus floor under the truck prior to moving out onto the apron or afterward. Right off the bat, you should be able to tell what fluid it is: Red or green tint or hue is coolant; red tint or hue is transmission (different viscosity than coolant); black or brown tint or hue is oil; clear is hydraulic, power steering or water.
Be diligent and do not take anything for granted. Notify the proper personnel as soon as possible when abnormalities are noticed. It is much better to be safe than sorry — for you, your crew, and the citizens. Be safe!
