Am I wrecking my pump?

I just started out 6 weeks ago at the pressure washing thing. I have a contract to wash delivery trucks twice a week. As I wash the trucks with a brush, my machine is still running for 3 to 5 minutes at a time without water running through it. I do this for over 20 trucks, will this kill my pump? I can't leave the gun open the whole time because i'm running off a tank in my van with just enough water to get the job done. What can I do to not kill my pump?

Sean K.

You are walking a thin line with those bypass times, especially as the weather and water warm up. The best life line for your pump is a bypass hose that dumps back into the tank. You cannot use upstream chemical application because you will have a water / chemical mix returning to your rinse tank, but downstreaming will be just fine. Do you use a hot water pressure washer? If so, there are chemicals designed to reduce, if not eliminate, brushing altogether.

I used to have a similar problem when I started out, I had to climb up and down trailers and leave the machine running.( dropped that account when I found an easier one) I had the bypass hooked to my tank and still went through the packing in my pumps every 6-9 months. I now run an open gun and am going on 1 1/2 years without touching my pump packing. Even in bypass to the tank, it is not great on them, but it is FAR better than not returing it to the tank at all.

P.S. Proper chems + the right application = no brush

you need to run your bypass back in to your tank this way water is always circulating

I Have Been Running This Way For Years Never Had To Change Seals Yet Knock On Wood