Boxxer 421- gray box not filling w/water

**Allstar** · 04-06-2010, 02:41 AM

My unit has 87 hrs and today I discovered the gray water box on top will not fill up. I turned the key on (not to start engine), and the water pump makes its usual humming sound, but isn't pumping water up to the box (from the fresh water tank).
I have a blue "bladder" next to the pump with an air valve but haven't touched it.
I manually raised & lowered the float in the gray box with no results. All fuses are fine. Waste tank empty. Machine runs great.
Hoping not to drive 2 hrs away for repairs.

**Allstar** · 04-06-2010, 03:23 AM

I plan to hook up garden hose directly to front of machine in the morning and see it that fills up the gray box. I'll run water thru the wand and check to see if the box stays filled or just drains again.

**Allstar** · 05-02-2010, 07:57 AM

Followup- The "Flo-Jet" water pump mounted on the fresh water tank must have been defective. I installed a new one and it immediately started pumping. My Interlink supplier will warranty out the original.
Now that I have 105 hrs, my new issue is heavy "pulsing" in the solution line. Starting to doubt this 421.

**Ara Klujian** · 05-03-2010, 11:08 AM

Maybe the pump ran dry and you burned out the seals in the manifold. This would cause air to enter and create cavitation. Look for water dripping from the manifold. Or else check the nitrogen accumulator to see if it needs a charge or replacement.

**Hydraman** · 05-05-2010, 09:31 AM

The 421 has a low water shut off protecting the pump from running dry, unless the low water float went bad which I doubt. You can test the float by lifting it up and down and listening for the pump clutch clicking on and off. The other reason that your pump is pulsating could be an improperly primed chemical system, try priming the chemical system again.

**Allstar** · 05-06-2010, 01:01 PM

I'll try the repriming of the chemical jug. There is no water leaking from the high pressure pump, only a small amt of oil (from what appears to be the site glass).
I think my machine might be running too hot because the pulsating gets stronger when the machine is up to 220+. I'm posting another thread with questions re: 2 other strange issues.