Max 28XL HST Pressure Help

[Brill]

Hello all, new to the forum here.... Had a question regarding the hydraulic pressure on my Max 28xl. As with many others with the same machine have discussed on here, I'd like to make sure my pressure is where it should be. I've installed an inline gauge at the loader pressure port, as Mike69440 has done (see pic), and now need to learn a little bit more on how to use it correctly. After I installed the gauge, I fired it up, and at idle it stays at zero. When I lift the loader all the way to the top and it stops, it only reads 1000psi. I also tried to lift the back of my truck up from under the trailer hitch and got the same reading. From what I've gathered on this great site, shouldn't it be around 2000- 2250psi? Can it really be that far below normal, or do I have something hooked up wrong, or should I be plugging the gauge in somewhere else? haven't messed with any of the relief valve adjustments yet, as I wanted to get some insight first. I am fairly mechanically inclined, but haven't done a lot with hydraulics...TIA

 

[K5lwq]

I would put the gauge on the curl circuit to test the relief setting. You have it on line in which is before the relief valve. I do not know what the pressure should be on your tractor.

 

[LD1]

With where its hooked, 0 at idle is normal. Because you arent doing anything that requires pressure.....the fluid is simply flowing through the valve unobstructed and back to tank.

Now lifting the loader all the way to the top, or trying to pick up something that is too heavy and stalls the loader "should" give you the relief pressure provided you held the joystick there long enough to make it go into relief mode....and also provided you were moving the lever all the way....otherwise if you were feathering the joystick, some of the fluid was bypassing the function you were trying to do.

Easiest way to pressure test is to put a quick coupler on that matches your loader valve. Unhook one of your loader hoses and hook that gauge on and activate that function with the joystick. Doesnt matter which one, lift, curl, dump, etc. Just makesure you move the joystick to activate whatever function you hook the gauge to.

 

[Brill]

With where its hooked, 0 at idle is normal. Because you arent doing anything that requires pressure.....the fluid is simply flowing through the valve unobstructed and back to tank.

Now lifting the loader all the way to the top, or trying to pick up something that is too heavy and stalls the loader "should" give you the relief pressure provided you held the joystick there long enough to make it go into relief mode....and also provided you were moving the lever all the way....otherwise if you were feathering the joystick, some of the fluid was bypassing the function you were trying to do.

Easiest way to pressure test is to put a quick coupler on that matches your loader valve. Unhook one of your loader hoses and hook that gauge on and activate that function with the joystick. Doesnt matter which one, lift, curl, dump, etc. Just makesure you move the joystick to activate whatever function you hook the gauge to.

Yeah I put the loader bucket under my trailer hitch frame and tried to lift it off the ground until it stopped while I was holding the lever wide open,(and yes I held it open for a bit) and pressure said about 1000psi. Also I tried various rpms and didn't seem to make much difference. So you think I'd get a different reading if I were to get a quick connect hose made up and plugged into a port? I tried messaging mike69440, as he has this same setup and has been through all of this already, but he hasn't been on here since early March. Curious as to what his gauge reads for comparison...

Today I might try playing with the loader relief valve some to see which way raises and which way lowers pressure, but I think trying to get another 1200 psi by adjusting relief doesn't seem right. If I am in fact reading pressure the correct way, I'm thinking it could possibly need a pump to be that low from spec (2060psi)...

 

[Brill]

I would put the gauge on the curl circuit to test the relief setting. You have it on line in which is before the relief valve. I do not know what the pressure should be on your tractor.

Pressure should be 2060psi give or take...

 

[Brill]

Just an update. I couldn't believe that my tractor was over 1000psi less than it should be, so I brought the new gauge back to the hydraulic shop that I bought it from this morning and had them test it. He was very doubtful, (and so was I) that a brand new gauge would be off that much, but lo and behold it was 1000psi off on their equipment as well. They applied 1500psi to it and it only read 500psi. So they gave me a new one (and tested it), I installed it, and now I'm reading just under 2000psi on my Max 28xl. Glad it was that simple.

Now to find a .025 x 11/16" washer to shim my relief valve and get it up around 2250psi...

 

[rdinatal]

Now to find a .025 x 11/16" washer to shim my relief valve and get it up around 2250psi...

Did you find one?

 

[Scrambler82]

Just an update.

Now to find a .025 x 11/16" washer to shim my relief valve and get it up around 2250psi...

Was wonder where you found your Washer ?