Troubleshooting a "Skipping" Pump

      When the fluid pump in an air-assisted airless rig loses pressure intermittently, clean out the ball check valve. July 27, 2008

I was spraying this morning to get a job out the door this week when my pump began to skip a beat. The spray would pause for a small portion of the pump cycle. I haven't encountered this maintenance issue with this unit and I'm wondering what I have to do to correct it the next time it happens. Is it something with the check balls at the bottom? I got the unit running again by blowing out all the paint and running thinner thru the lines.

Forum Responses
(Finishing Forum)
From contributor A:
Have you checked the filter at the gun?

From contributor B:
Here is your fix in less than fifteen minutes. Unscrew the black hose and above it there is a hex nut. You will find a ball check there. Clean it well. I'm ninety percent sure, you have junk in there, and the junk doesn't let the ball seat in the groove.

From contributor C:
I have found a clogged siphon tube and hose before. Sometimes a piece of the 5 gallon can gasket has gotten caught in the line.

From contributor D:
I agree with contributor B. This has happened to me numerous times. That's usually the culprit.

From the original questioner:
That's what it was, all right! Found a chip of wood. Imagine that, in a cabinet shop, no less. Thanks for the help, guys.

From contributor E:
To contributor B: Nice Tip! Darn those wood chips ;)

Would you like to add information to this article?
Interested in writing or submitting an article?
Have a question about this article?

Have you reviewed the related Knowledge Base areas below?
  • KnowledgeBase: Knowledge Base

  • KnowledgeBase: Finishing

  • KnowledgeBase: Finishing: General Wood Finishing

    Would you like to add information to this article? ... Click Here

    If you have a question regarding a Knowledge Base article, your best chance at uncovering an answer is to search the entire Knowledge Base for related articles or to post your question at the appropriate WOODWEB Forum. Before posting your message, be sure to
    review our Forum Guidelines.

    Questions entered in the Knowledge Base Article comment form will not generate responses! A list of WOODWEB Forums can be found at WOODWEB's Site Map.

    When you post your question at the Forum, be sure to include references to the Knowledge Base article that inspired your question. The more information you provide with your question, the better your chances are of receiving responses.

    Return to beginning of article.

    Refer a Friend || Read This Important Information || Site Map || Privacy Policy || Site User Agreement

    Letters, questions or comments? E-Mail us and let us know what you think. Be sure to review our Frequently Asked Questions page.

    Contact us to discuss advertising or to report problems with this site.

    To report a problem, send an e-mail to our Webmaster

    Copyright © 1996-2016 - WOODWEB ® Inc.
    All rights reserved. No part of this publication may be reproduced in any manner without permission of the Editor.
    Review WOODWEB's Copyright Policy.

    The editors, writers, and staff at WOODWEB try to promote safe practices. What is safe for one woodworker under certain conditions may not be safe for others in different circumstances. Readers should undertake the use of materials and methods discussed at WOODWEB after considerate evaluation, and at their own risk.

    WOODWEB, Inc.
    335 Bedell Road
    Montrose, PA 18801

    Contact WOODWEB

  • WOODWEB - the leading resource for professional woodworkers

      Home » Knowledge Base » Knowledge Base Article