Build:
- Predator 459 CC Engine
- Envirospec 6.3 GPM Pump
- 45 Gal Buffer Tank
- K1 Unloader
A link to the build >> 6.5 GPM Predator 459 Budget Build - Google Drive
Issue
I’ve made this build once before and had zero issues. Once everything was built, I started up the engine to find there was no water coming out. Bone dry. I contacted the pump manufacture and explained the problem and they said it was common that before sending these units, the techs sometimes use to much locktight, causing the check valves to “stick”, explaining that was one of the biggest issues / phones calls they received about these pumps.
They told me to check the lower valves. Me, having basic small engine repair capabilities was not at all thrilled in taking the pump apart, but after some reading i figured it wasn’t that scarry. I went ahead and unbolted the lower check valves starting with the one closest to the pump inlet. I cant be fore sure but I could have sworn the valve was almost sideways, before water cam gushing out. I only inspected the check valve for a few seconds before placing the nipple properly seated in the bolt and putting it back.
I did this to all three. after doing some more digging I should have insured the functionality of the check valves themselves - making sure the spring mechanism functions, there are no debris etc, before putting them back.
Result
After I was done, I fired up the machine and thankfully, water (and pressure) was coming out. With 200 ft line, un-reeled I used my PSI gauge (at the gun, or end of the 200 line ) and began calibrating the machine. My method was as follows.
With the machine on, trigger pulled, I incremented the psi in half inch turns, watching the psi rise. I would let off the trigger every 5 - 10 seconds just because. I found that it took a lot of turns just to get to 1500 - 2000 psi. The pressure was increasing, and continuous, but the unloader bolt was much further then I remember my first build being. Its when I got the pressure to about 2000 - 2500 psi when I knew something was wrong.
When I let go of the trigger the needle on the gauge spiked up so fast I could barely see it hit 3000 - 4000 psi, then back down to zero.
You know how when its properly calibrated, you let off the trigger and it jumps a few hundred psi, and almost sounds like a vehicle down shift ?
Well that was not the case. It SLAMS up, so much I though something was going to burst. so, i brough it back down to about a steady 1000 psi. When I let go of the trigger it quickly bounces up to about 2000 psi, but it doesn’t SPIKE, then back down to zero.
I was able to surface clean effectivity, some stone paver for about an hour today. But I wasn’t able to use my down stream injector, which was working on my other build a few weeks ago. Replaced the spring, ball, tiny seal inside, still nothing. So i suspect its not enough psi to draw from. (obviously)
So now, I feel like my next best steps is to check each check valve, upper and lower - making sure the spring mechanism works and there is no debris or anything obstructing the function.
I know this is incredibly long but now you have all the bases covered to help me troubleshoot.
Also, side not, yes I did all the initial “level 1” troubleshooting, ie. checking for leaks, air in the system, worn seals, etc. and it seems everything passed.
Thanks in advance for your help.
