Vacuum Pump Drivelines

driveshaft-fadeVacuum pump driveline failures usually involve lengthy downtimes and a big service bill. Broken keyways, gears, drive shaft or couplers can result from a variety of causes. Here are some considerations that may help you avoid the hassle.
One of the most basic things that you can do to prevent premature failure of your driveline is make sure to engage your PTO slowly. This will soften the shock load transferred down the driveline.

For manual transmissions with an air shift PTO, the sequence should be as follows:

1. Verify that the truck engine speed is at an idle
2. Depress the clutch pedal
3. Engage the PTO switch, button or lever
4. Slowly release the clutch.

For hot shift PTOs on automatic transmissions, you only have limited control. Low engine speed, and possibly installing a soft start PTO, will significantly reduce the shock load transferred down the driveline when you engage your hot shift PTO.
Maintenance is very limited on the pump driveline. One of the main things you can do is keep your eyes and ears open for anything abnormal while you operate your truck on a daily basis. You should check the oil levels in the transmission and gearbox. Most gearboxes are sealed with no level indicators, but simply checking for leaks under the gearbox and on the PTO itself, at the side of the transmission housing, is a good idea. Make sure the set bolts on your PTO shaft are tight. Some manufacturers may install safety wires to prevent loose bolts. You should also regularly grease your slip joints and U-joint and verify that the U-joint has not loosened. When you engage your PTO, there should be an indicator light that comes on. Make sure the light is working consistently to prevent accidental drive-a-ways with the PTO engaged.

Safety should always be a consideration when maintenance work is being done. Never get under a truck if the PTO is engaged. You may be tempted to have someone engage the PTO while you are close by to examine the driveline. Different manufacturers install different types of drive shafts. Even the balanced smooth round drive shafts can be dangerous. Keep clear at all times.
Most of these concepts are just simple things that you can do on a daily basis as you operate your truck. However, the old proverb that “an ounce of prevention is worth a pound of cure” is always applicable. Knowing your truck inside and out and getting into the habit of listening, looking and double-checking will help prevent driveline failure and keep your pumper truck operating smoothly.

Story by CLINT MORRIS -Pik Rite, Inc.

Clint has 13 years of experience with customer service at Pik Rite, Inc. His knowledge and expertise in the liquid waste industry is highly valued. Pik Rite manufactures and services commercial vacuum tanks, hoist units, roll-offs, slide-ins, portable toilet service units and tank trailers ranging in size from 300 to 6,500 gallons. Pik Rite, Inc’s 15-year-steel tank warranty sets it apart from the competition. Tanks are available in steel, stainless steel and aluminum.
