Tips for Keeping That Vacuum Pump Running at Peak Performance

The wheels still roll, but lose suction power and your truck might as well be dead on the side of the road. A proper maintenance plan will keep you pumping on the busy days ahead.

Tips for Keeping That Vacuum Pump Running at Peak Performance

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A vacuum pump is the beating heart of your septic service truck. You pull the lever and expect it to work hard and perform reliably every day. As such, a solid preventive maintenance routine is the key to avoid unexpected — and costly — breakdowns.

Fred Hill, owner of Washington, D.C., Gotta Go Now, committed to a rigorous routine pump maintenance schedule early on for his portable sanitation and pumping company, and the savings he reaped are impressive.

“I didn’t do it the first year, and that forced me into a position where I ended up buying pumps to replace,” Hill says. “After that I said, ‘Hey, we can do preventive maintenance and save a ton of money,’ and at that point we put into place the regular maintenance program to keep us from having to buy pumps all the time.”

As important as knowing the proper steps to take is building a routine and getting drivers to commit to that schedule.

“When the truck drivers arrive in the morning, they’re required to do their pretrip, and part of that is to drain down the pumps if they hadn’t done it the day before,” Hill says. “Sometimes they come (back to the shop) pretty late, so I don’t ask them to do it every evening. But at least before they go out the next morning, they need to drain down the catch reservoir and then refill the fill tank with clean oil, thereby keeping the pump ready to use.”

CAN’T TAKE THE HEAT

The foremost downfall of vacuum pumps is overheating, and a single maintenance item — possibly the simplest of all — is often responsible.

“A big factor that we’re finding to be a problem is people aren’t cleaning the pump, and they’re letting mud build up on the pump,” says Todd Devecsery, national sales manager with Fruitland. Many pumpers are in the habit of keeping their pumps clean, but a refresher for your drivers is always a good idea.

“Don’t let mud build up on your pump. It’ll act like a blanket. Even if your pumps are liquid-cooled, they still need some ambient cooling, and air-cooled pumps rely on heat dissipation. If you’ve got a half-inch of mud built up on it, it’s not going to allow the heat to escape — heat is one of the biggest enemies of the pump,” says John Gilbert, sales manager with pump manufacturer Masport. “Externally, cleaning the pump is literally just pressure-washing like at a car wash.”

Ensuring that the pump is properly oiled can be a factor in overheating, but lubrication also contributes to the longevity of many pump components and efficient pump operation. An often-overlooked piece of pump care is the oil pump. Oil consumption testing can tell you whether the oil pump is operating properly. If it’s not, it could be catastrophic for the pump.

“Without any oil getting to the vanes, the pump will overheat. The friction will be too great inside the pump, and then it will not operate and it will fail,” Devecsery says.

Leaks are another big danger. Undetected leaking can potentially lead to damaging increased friction inside the pump, but it can rob the pump of its ability to create adequate vacuum to get the job done.

“Most people don’t realize this: Without a sealed environment — I mean hermetically sealed, perfectly sealed, 100% sealed — a vacuum truck does not work,” Devecsery says. “A lot of the drivers don’t take that into account.”

Along with regularly checking seals and gaskets for leaks, a simple way to encourage a maintenance mindset is to have drivers routinely check pressure and vacuum. Testing the system with a small amount of pressure and vacuum for 10 minutes before leaving the shop can help catch issues before they cause downtime, and doing it regularly can help catch issues before they become more serious.

KNOW YOUR PUMPS

Unfortunately, pump care isn’t as simple as occasionally giving them a thorough cleaning. Knowing how to run the pump is also key in promoting its longevity. One common misunderstanding is that the relief valves are not typically preset by the manufacturer or builder on vacuum systems.

“Vacuum relief serves adequate air into the tank: The vac relief starts sucking air in and produces what we call air conveyance, and then it pulls the product into the tank,” Devecsery says. “You need to have air to create pressure, and you need to have a relief to allow the system to operate effectively. This is the key caveat of the whole deal: They’re not set. So a person gets a brand-new piece of equipment and the reliefs aren’t set at all. They have to know how to set them.”

Not only can improper settings cause periodic issues on the job site, such as inefficient loading or even pump failure, but they can do more damage over the long haul.

“Knowing your pump speed and knowing to operate the pump at the right speed are crucial for the life of the pump and overheating,” Gilbert says. “Have the vacuum or pressure relief valves at the right settings; number one, don’t exceed the maximum continuous recommendation for the pump. And then don’t set it too high for the actual work you need. Say one of our pumps can run at 25 inches of vacuum continuously — yes, it’ll do that all day long, but that’s kind of like redlining your car all day long. If you don’t need it, don’t use it, because the higher vacuum and higher pressure just creates more heat.”

START A ROUTINE

One easy tip for incorporating pump maintenance into existing schedules is to tie certain preventive items to planned truck maintenance. For example, Fruitland recommends a checklist of pump maintenance to coincide with truck engine oil changes:

Set or check the relief valve.

Full pump flush.

Check, empty and clean oil reservoir; adjust oil pump if necessary.

Check rotation speed of pump with laser tachometer.

Some contractors, such as Gotta Go Now, choose to schedule pump maintenance by time intervals: daily draining of catch reservoirs and refilling of fill reservoirs; flushing and seal/leak check monthly; and full teardown, component replacement and rebuild annually.

Taking the pump apart occasionally for visual inspection ensures that secondary wear isn’t occurring on the vanes. Beyond the expected tip tolerances, vanes can wear and cup in the center or become pitted and “mushroomed,” not all of which can be seen from inspection ports.

“Personally, I’d rather see the pump opened up for a visual inspection of the whole vane,” Gilbert says. “Checking the height is one thing, but actually looking at the vanes — there’s other underlying issues that can happen. You can get dimples in the vane slots that’ll make the vane hang up and wear at an angle. If there’s any glazing on the tips, you can tell the pump has been running with a lack of oil or running too hot.”

Gilbert actually recommends flushing on a weekly basis, but it depends on manufacturer recommendations for individual pumps and the amount of use a pump sees day to day. Masport has a series of video resources on its website with flushing guidelines, as well as its recommendations for time-interval maintenance.

“In a perfect laboratory world, theoretically, oil should be coating every surface and the vanes should never really wear out,” Gilbert says. “Some jobs are worse than others, but a lot of the systems do ingest dust and dirt, you get liquid carryover, and that creates wear. Down the road, that’ll lead to oil leaking. Maintaining the components is key for keeping your pump alive.”

VANE BASICS

Vanes naturally rub against the inside of the pump casing during operation, and if the pump isn’t flushed and oiled properly, vanes wear out more quickly. And no matter the diligence in maintenance, some material carryover is inevitable, so vanes may still need to be replaced occasionally.

“Vanes come in different thicknesses and heights; different pump manufacturers should have a wear tolerance on it, as far as when they need to be replaced,” Gilbert says. “It’s kind of like brake pads. If it gets below a certain amount of wear, you want to replace them.”

While vanes used to be made of asbestos-based materials, modern versions are typically made of Kevlar and phenolic resin. It’s a durable material, but its resilience shouldn’t be taken for granted.

Vacuum pumps can have anywhere from three to eight vanes in a variety of sizes and tolerances.

“You want to keep it within the manufacturer’s spec. Differences in materials grow completely different under heat and your tolerances change,” Gilbert says. “Looking at some of our vanes, 3/8 of an inch is the maximum height wear you want before replacing them.”

When it comes to replacements, most pump companies will sell vane sets, and some will offer full rebuild kits with vanes, bearings, gaskets and seals.

It can be tempting to put this maintenance on the back burner, but it can have a catastrophic effect on the pump if neglected.

“If it gets to a point where it’s not going back in the slot like it should, it’ll break in half,” Gilbert says. “The vanes will fall out of a slot. Then once they wedge up in the top of the cylinder, you’re going to break something cast iron.”

JUST DO IT

There’s perhaps no better way to bring home the point about pump maintenance than comparing the ages of pumps: maintained versus not. Hill says in the early days of his company, before establishing his maintenance program, one of his pumps failed after only about 16 months. Gilbert hears from many customers whose pumps failed after only a handful of years.

On the other hand, lasting a decade is a cakewalk for a well-kept pump, experts say.

“I have a pump right now that is 14 years old and is still being used,” Hill says. “If you go out and buy a pump, you’re out $3,000, $4,000 because you didn’t set up a maintenance program, which you’re only spending a couple hundred dollars on annually.”

The bottom line is that proper pump maintenance for a fleet of vacuum trucks can save pumping companies thousands of dollars over the years.

“Keeping the pump clean, flushed out — that can extend the pump life, keeping your repair costs and downtime costs low,” Gilbert says. “The pump is basically the life of the truck, so if it’s not working, you have a whole vacuum truck that’s basically unusable. You depend on the pump every day.”  



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