maintenance
& restoration
as well. Be sure to replace all filters at the same time.
External contamination can also be a problem. If the
pump is not properly protected while washing the engine, oil
and solvents can enter through the exhaust port and induce
pump failure. Vacuum pumps are also designed with a drive
coupling that connects the vacuum pump to the engine
gears and is made to shear in the event of a pump failure in
order to protect the engine. The coupling is designed to have
The vacuum pump drive coupling is designed to shear in the event
of a pump failure in order to protect the engine.
a service life of six years. However, exposure to oil through
a failed seal on the engine, or from around the engine, will
quickly erode the coupling and lead to an early failure.
Mishandling—There is no good reason for a pump
to fail due to mishandling, but it does happen. A vacuum
pump and a vise simply aren’t meant for each other.
Ham-fisted mechanics who use a vise on the pump when
removing/installing fittings can distort the pump enough
to cause an early and unpredictable failure. Also, just like a
spark plug, a pump that has been dropped should never be
installed on the engine.
Overheating and Overworking—Finally, overworking and overheating can cause failures. In most cases, this
kind of damage is the result of problems in other parts of the
vacuum system. Faulty regulators and de-icing components,
as well as kinked hoses and fittings, can place an extreme
workload on the pump. This causes excessive backpressure,
which leads to flank wear and, ultimately, vane failure.
Tips for Vacuum Pump Installation
Avoiding vacuum pump failure begins with proper installation. As mentioned before, the filters should be replaced
and all hoses should be inspected to ensure that they are
not deteriorated and do not have any residual rubber or
carbon pieces that could be ingested into the pump.
Next, the existing Garlock oil seal should be replaced
on the pump pad. Even if the seal is not leaking, it is
important to replace it. These seals have a finite service
