Broken Pump?

Hi All,

First and foremost, I’m new to the site and would like to thank you all for the content. I have a Northern Tool pressure washer with a CAT pump that I’m having a little difficulty with. In short, the pump pulsates and makes a grinding sound when the trigger is not pulled; however, appears to operate normally when the trigger is pulled.

Northern Tool says this is normal operation; however, I do not recall this happening last year and it is not how my other machines work.

Any ideas? Do you think it is worth rebuilding the pump?

Video is as follows:

Thank you in advance.


Def interesting ! Dont know much about electric washers except gas is better lol… but I’m gonna follow your post in attempts to learn a thing or two maybe. Hope you figure it out bud !

It sprays normally? Perhaps an issue with the unloader?

When it’s running look around the machine and check for leaks.

Thanks! Yes, it runs and sprays normal when the trigger is pulled. I have not seen any leaks. Additionally, I checked the oil level. Everything seems normal with the exception of the sound and pulsating when the trigger is not pulled.

Also, I appreciate the direction. I’ll replace the unloader and see if that does the trick.