Identifying Tractor Smells
Listening To Your Tractor : Part 2
by Curtis Von Fange
We are continuing our series on learning to talk the language of our
tractor. Since we canít actually talk to our tractors, though some of
the older sect of farmers might disagree, we use our five physical
senses to observe and construe what our iron age friends are trying to
tell us. We have already talked about some of the colors the unit
might leave as clues to its well-being. Now we are going to use our
noses to diagnose particular smells.
While bushogging in the back field one year some rather large bushes
forced some wiring to come in contact with the fan belt pulley. After
a little time the wires rubbed through the wire insulation and shorted
against each. An odor similar to leaving a milk carton on the stove
roiled around the tractor seat. The smell of cooking plastic prompted
me to shut off the tractor, quickly disconnect the ground cable from
the battery and look for the problem.
Electrical odors can be the most dangerous of tractor smells. A hot
wire grounding to the frame or another circuit can flash melt an
entire wiring harness in a matter of seconds. If the shorted wires
are near a fuel line the overheated wires can burn through a rubber
gas hose and ignite the tractor. Similarly they can ignite a fluff
ball of milkweed pods stuffed under the radiator cowling or a ball of
oil soaked grass wedged behind the steering box or under the battery
plate. It is important to recognize the particular odor that this
threat puts out. Since the smell is actually the plastic insulation
melting and/or burning off of the copper strands of the wire the
characteristic odor is almost the same as what a plastic bottle in a
burn can would smell like. Another example would be the hairdryer
that your daughter or wife overuses in the morning. That particular
odor is a marker to shut off the tractor and look for problems. If
possible always carry a battery wrench in your tractor tool box and
quickly disconnect the negative battery cable end from the terminal
post in order to minimize the damage potential.
After I got the tractor shut off I was able to locate the errant wire
by looking for obvious wire rubbing and then checking the wire casing
for rub-throughs. In many cases by the time the battery gets
disconnected the wire has already done a job of melting the
insulation. By tracing the melting to the furthest point away from
the battery the bad spot can usually be identified. Look for rubbed
wires against metal or places where the wire has crimped back on
itself or even melted though another crossing wire. Also look for
wires that pass underneath fixtures like the radiator or cowling.
Sometimes a bushing will wear out and cause a fixture shift which will
crimp or crack a wire.
One of the most prominent odors is an overheated engine steaming out
antifreeze. Just about everyone is acquainted with the sweet, syrupy
smell that boiling coolant gives off. Usually it accompanies a broken
radiator hose or a rusty radiator cap that has lowered the coolant
pressure enough to let antifreeze pour over the fan and onto the rest
of the engine and, from there, onto the operator. It is really handy
to recognize the antifreeze smell before the soaking occurs. The
smell is characterized by a sweet almost sugary odor. When noticed
the tractor should be shut off and the leakage spot determined. Look
for pin holes in the radiator and/or corresponding hoses, the cap,
overflow tube, or water pump bushings, seal, or gaskets. Check the
temperature gauge to see if the leakage is a result of overheating or
a potential cause for overheating.
Fuel smells, like electrical, can be a serious hazard if not located
and repaired. Other than a result of spillage during tank fillage or
a case of severe engine flooding, there should be no odor from diesel
or gasoline fuel systems. A strong fuel odor is characteristic of a
leaking fuel pump, a broken fuel line, or a leaking fuel tank. Other
sources can be an overchoked carburetor filling the air intake line
with raw gas, a leaking fuel injection pump, or loose injector. Loose
fuel in the wrong places can rapidly turn to vapor on a hot engine and
be ignited by hot exhaust manifolds, sparking distributors or loose
exhaust pipes which spit sparks. Take care not to operate the unit
with stray fuel leaking out.
Another of the more common smells is that of burning oil. This odor
is quite similar to burning cooking oil on an overheated iron skillet.
It seems to show up the most from the bottom of leaky valve covers,
with the dirty oil dripping down on the exhaust manifold. The oily
aroma is potent and easily smelled, especially when the tractor is
shut off....the smell just kind of lingers. Replace the gaskets under
the leaking part before the oil residue builds up and creates a
hardened oil crust which is unsightly, collects dust and dirt, and is
really difficult to clean off.
All of the above smells are indicative of relatively cheap repairs.
Unfortunately, because they tend to be cheap, they never get fixed.
On the other hand when the aroma of burning high temperature friction
discs crosses onesí nostrils immediate attention should be done. The
smell can be easily associated with that of overheated truck brakes on
a narrow mountain road or that of ones son or daughter trying to get
manual transmission car out of a snow bank for the first time. Unlike
the smell of oil or possibly antifreeze, it is wise to discontinue
activity as soon as the odor comes to the driverís seat. Internal
brake discs and friction clutches are not only expensive but are hard
to get to and the associated pressure plates and flywheel surfaces can
often be damaged by the excessive heat buildup. Take care to find
give adequate cool off time for the discs before trying to resume the
Taking the time to acquaint oneself with the assorted odors that a
tractor gives off can be very beneficial to extending the lifespan and
service time of your unit. Tractor odors can be the first line of
defense for catching problems before they occur because one doesnít
have to actually isolate and see the problem. The particular smell
can catch ones attention while watching a bushog or can be a
definitive identifier while working at night or under inclement
conditions. These odors are yet another way of learning how to
communicate with our old iron....maybe those older farmers knew
something after all....
Today's Featured Article -
Stories From Old Farmer - by K. Pratt. Old Farmer, a.k.a. Dale Jensen began posting messages to our discussion forums at the grand age of 75. With extensive knowledge of farming and tractors, he valued the past and the ways that went with it. He shared these values with us until shortly before his passing. I spoke with Dale in his last days and requested his permission to share some of his stories with the readers of our magazine. He agreed, and provided the
... [Read Article]
Looking for a skid for a W_power unit----also a green & yellow John Deere antifreeze gallon can.
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