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Why the vacuum level of the vacuum pump can’t increase?

the vacuum pump filter

When you’re using a rotary vane pump and finding that the vacuum level isn’t rising as it should, right? And on top of that, you’ve got this annoying noise going on. Well, buddy, let me tell you what’s probably causing these issues.


First off, if your pump ain’t sucking in air like it’s supposed to, it could be because the rotor ain’t turning. You can check this by seeing if the pump wheel is spinning but not making any valve sound or if the shaft ain’t moving with the wheel. If that’s the case, chances are the key has fallen off or broken.

Just reinstall it, and you’ll be good to go. Sometimes, when you’ve got a combination pump with both high and low vacuum rotors, the slots on the gears might get damaged, which means only the high vacuum rotor will spin while the low vacuum one stays still. This can also cause the issue you’re having.

The bottom line is, make sure you keep an eye on your pump parts and give ’em some tender loving care. Don’t forget to do your daily maintenance checks, and don’t be lazy about fixing small stuff like replacing a missing ball or spring in the exhaust valve.

These little things can add up and cause big problems down the road.


Now, for the second scenario: your pump’s sucking in too much air. When this happens, you’ll hear a loud noise, see the valve plates vibrating, and maybe even notice some smoke coming from the oil bucket on top of the tank. In extreme cases, you might even have some oil splashing around.

What’s happening here is that a lot of exhaust gas is slamming into the oil inside the pump. If this happens just when you start up the pump, it’s usually nothing to worry about.

But if you’ve got oil splashing all over the place, it could mean you’ve put in too much oil or the anti-splash mechanism ain’t doing its job. Installing a good-quality exhaust filter can help prevent oil splashing.

Now, if you’ve done all that and the problem’s still there, it’s likely that your pump is sucking in too much air.

This could happen if the rubber hose connecting the pump to the system has come loose or is damaged, or if the exhaust valve at the front end ain’t closed properly.

If the system itself is busted, you might need to replace the whole pump. For other issues, just take the appropriate measures to fix ’em.

Keep in mind that minor damage to pump parts won’t necessarily cause the pump to suck in too much air – it’ll just lower the vacuum level.


So, there you have it, my friend. Rotary vane pumps can be tricky to troubleshoot sometimes, so it’s best to nip potential problems in the bud with regular inspections and maintenance.

Remember, a quality exhaust filter is not only a safeguard for your pump but also helps solve emission issues. Good luck with your pump, and stay safe out there!

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