Q. How do you set Vacuum on the vacuum relief valve?

A. Click Here


Q. Why choose Crescent Tank?

A. Push the button to find out our secret. 


Q. How does the PTO and Vacuum Pump work?

A. Click Here


Q. I would like a copy of the service chart.

A. Click here for the service chart.


Q. My Tank is not drawing good vacuum.  How can I check it?

A1. Disconnect the Vacuum hose.  If you have steady vacuum when hose is not connected you have a clog in the hose.  To clear the hose turn the hose around and connect the oposite end then turn on vacuum.  That will clear the clog.  You could have a clog in the wand if it is not in the hose.  Clear the wand.

A2. Flush the vacuum Pump.

  • Use a flush kit.  

  • If you do not have a flush kit

  1. ​Disconnect the hose from the pump

  2. Dump in Diesel/Oil Mix

  3. Drain the Oil Catch Muffler

A3. Clean all traps and oil catch muffler

  • Loosen slowly to avoid breaking parts

A4. Make sure the plate inside the check valve moves freely.  Note that older models do not have a check valve.

A5. Check the RPM's.  If the RPM's are too high it will cause the Primary or secondary to trap off early.


Q. Why is my tank trapping off early?

A. If your tank is trapping off too early it could be the following reasons.

  • You are leaving your vacuum running from stop to stop.  Do not leave the vacuum running while you are driving.

  • Your liquid could be sloshing or surging which causes the ball to pop up in the trap.

  • Your tank could be slanting forward which would cause it to "feel full".

Q. My 12V water pump is running intermittently or pulsating. What could be the problem?

A. Try the following.

  • There could be air between the pump and the end of the hose.  

  • There could be a leak in the hose.

  • Call our shop for more detail. Contact us.

Q. Where can I find a copy of the owners manual.

A. Please send a message to info@crescenttank.com to request a copy of the owners manual.  We can send an electronic version at no charge.















Call us today at 585-657-4104 or Email us at info@crescenttank.com to get an estimate.