K7 unloader cycling

Ok, my K7 is still cycling bad. I’ve noticed something recently though. Sometimes when I get on the trigger, it seems like I have a little air in my line. And I’ve noticed some air a few times in my bypass hose when I come back to the trailer to swap my ball valve. I’ve tried to check all my connections but don’t see any loose fittings. Any idea where I could or would be getting air in my pressure line?

Ds inj still plugged in? Or air into supply. What type if connections are you using?

Do you have a thermal relief valve somewhere ? I had one on my unloader sucking in air once. @BigJake solved that problem for me.As far as the cycling goes ,I had a tiny leak coming out of my lance when off trigger, it was the gun going bad ,causing the unloader to cycle and rebuild pressure. Just spit balling.

1 Like

Yes, injector still plugged in. I have a jumper from machine to the injector which is plugged into the reel. Then two 100 foot sections of pressure hose that are attached direct with no quick connects on reel or between hoses. No leaks that I can see. I did see air bubbles in my bypass hose so air is coming from somewhere.

Havne’t noticed anything on my gun, but will check it out tomorrow. And no thermal relief. Some days it runs perfect, and others it seems like it cycles like crazy. I just noticed that it seemed like I was getting some air when I pulled the trigger and today is first time I’ve noticed air bubbles in my bypass line. Seems like this K7 is very finicky

1 Like

Is you bypass line spilling in your buffer tank causing air bubbles? or cascading down the side.

It’s directed to the side of the buffer. No air in the supply, only in the bypass.

Do you ever empty your buffer completely between jobs? Seems some air could get trapped in your filter housing and cause some trouble. If I empty my tank completely, I’ll get some surging on my pump if I don’t open the drain on my filter and let all the air out. My Y-trap is mounted upside down, though.

Any camlock fittings between tank and pump? Those can leak some air in sometimes, as well.

@dperez seems to know a lot about what makes flow unloaders tick

I’d re-teflon the fitting going into the tank bulkhead. My guess is it’s pulling air somewhere in that lil stretch from the tank to pump.

1 Like

I think I figured it out. The next day I had my jumper hose blow. Seems better after swapping hoses out. Think maybe it was about to blow and air was getting in. Seems better now, but will see if it holds up.

1 Like

Well I’ll be, I would of never figured that one out.
Good deal ,you’ve been diagnosing that for a while.@surfacemedic

Good deal, AG hose makes very nice bypass hose. I use 3/8 single wire since I have it on hand, it’s only a 16" run and I need the swivel on it for installation.

1 Like

Never thought to check that either. I checked the connections, but not the actual hose. Glad to have it figured out for sure