Loader pressure test and adjustment

   / Loader pressure test and adjustment #11  
I don't understand why they recommend max RPM?

All of my machines will develop max pressure (open the relief valve) at idle.

If a pump is worn enough, it won't open the PRV at idle.

Oil exiting via the relief causes a pressure increase due to the restriction the relief valve creates.

The use of max rpm's is taking that restriction into account so, should you set relief at low rpm's, you can experience higher pressures with the engine rpm's up as more oil is exiting through the relief valve

Dave M7040
   / Loader pressure test and adjustment #12  
Will the system spool up to maximum pressure with just the gauge in place or should I have a T made up to allow the pressure to still operate the cylinders while I'm testing?

I test the RV settings on all my equipment. You don't really need any Tee fitting or QD, just somewhere convenient to connect the gauge. Anywhere that you can easily disconnect a line on a work-port and put a gauge to block the flow will work. I like to be near or on the cylinder so I can easily see which valve and direction I need to operate. I also cap the open cylinder port so dirt can't get in, and oil won't squirt out. Blocking the oil flow on a work port allows the pump to build pressure to relief without moving any cylinders.

Here is a short jerky vid I posted showing the process for my new mini-X. Conveniently, I had a AUX valve and line to attach my gauge to.
XN8 mini-excavator pressure test - YouTube
   / Loader pressure test and adjustment
  • Thread Starter
Well I'm resurrecting this thread as I'm reasonably sure my pressures are not right. I'm happy however to post that the pressure setting I found out is 2200 psi + or -100 psi. So I think I will be checking it this weekend.

FYI The loader is a Montana FEL 100 made by Amerequip.
   / Loader pressure test and adjustment
  • Thread Starter
Well I finally tested it and it was a needles width below 1900. That's about 300+ psi low. I could not find any shims. So I got a stainless steel washer with the same OD that is just a smidge thicker than the 3 shims in the valve already. I will try to adjust it this weekend. I saw on here that the FEL 100 on a larger Montana called for up to 2400 so as long as I reach 2200 psi and don't exceed 2400 psi I think I will leave it. I had a hell of a time finding a quick coupler that would fit and finally decided on using the AN fitting behind the male quick coupler. Nothing seems to go as planned with this tractor.
   / Loader pressure test and adjustment
  • Thread Starter
Well with the washers I was able to get 2300 psi at 2000 rpm and plan to leave it at that. Note: it was tough to start the threads on the cap as the washers hit the spring creating a great deal of preload to overcome. I suspect the spring is weak while the spring height is still at OEM height.
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