I was shim less !

[JimWalch]

After 300+ hours on my BX23 it was time to do some more maintenance and a specifications check. It just didn't seem to have as much power as when new. So my nephew made up a test gage to check the pressure. (See attached picture) Well guess what? Only had 1550 Lbs. out of the 1849 lbs. the book says. QUOTE]




What engine rpm, and oil temp did you have while measuring this pressure? The relief valve in the system has a rise rate while is dependant on oil viscosity and relief flow. Does the manual specify these conditions for setting the relief?

I can't tell the full scale range of the analog gauge in the photo, but assume its a 2500psi gauge. Even if its been in for annual calibration, figure it can be off by about 2%. Add to that the error in human reading of analog gauges.

Bottom line is that the system may have been within shipping specifications.

A lot of operators complain after using a vehicle for a while that it doesn't perform as well. My personal experience when performing focus groups in the field is that as an operator gains experience with a vehicle, they push it harder and feel it doesn't perform as well as when they first used the vehicle. This is depsite showing them that the vehicle is still performing the same as when they started operating it.

I've been through many times. Usually cylinders are broken, and when the system pressure is tested under controlled conditions, it is WAY too high.


Just some food for thought. Bumping pressures over factory spec's may give you a short term gain, but for a long term loss. In the case of the BX tractors, increasing system pressure once the tractor is broken in will cause the gear pump to experience additional 'cut-in' which literally shaves more aluminum off the pressure faces, which then is introduced to your hydraulic system. Normally this contamination is removed at the pump test stand, but now you are shaving aluminum while installed on your own tractor.

IowaAndy

My tractor sits in a heated building (and in AC in the summer).
The gauge is a 3000psi filled and the oil temp. was in the optimal range. At
WOT warm oil a little over 1900psi. with SUDT.
I always complain to myself about almost everything (therapy) but my nephew who used this bx new knows what is capable of. Now with 300+ hrs. he borrowed it again and thought it was not as powerful as when new. I trust his opinions even though he is half my age. He designs and builds after market farm equipment who just happens to hold a patent on one of his designs. That痴 why I have the gage from him so I could test it myself.

 

[ultrarunner]

Attached is a picture of mine...

Did you buy the gauge assembly already made-up? I like to get one.

 

[kennyd]

Did you buy the gauge assembly already made-up? I like to get one.

All the parts (gauge, 12" hose, and adapter) where purchased from the Surplus Center. The QD was from my JD dealer.

 

[RobJ]

I'd be careful doing this unless you really are losing power (real world loss). This'll bump the pressure on all the seals, hoses, cylinders, etc. Even though the manual has a spec, unless you tested a brand new tractor you really don't know if you lost a little or a lot of psi.

This might also make it easier to overload the loader or 3pt.

 

[Harry c]

Just a note for those who want to build a gauge setup:

You do not need the valve and "T", all you need is the gauge, a short piece of hose and a QD that fits one of your loader ports. You just plug in the gauge and operate the joystick to energize the port the gauge is plugged into. DO NOT HOLD THE JOYSTICK FOR A LONG TIME THOUGH as you are deadheading the hydraulic pump.

Attached is a picture of mine...

You don't even need the hydraulic hose. I just took the female QD off one of my loader hoses, screwed the gage into that QD, plugged it back onto the male QD from the valve. Any of the 4 ports will work but I chose the Yellow. There's no need to hook up the other 3 lines. Warm the engine and oil to normal before you test. Test at full throttle. Just pull the lever and see which direction moves the gage. Hold it for a couple of seconds and read... BX24 should be 1780 psi. Mine was right on the nose after 100+ hours. I checked it because??? Curious??? Bored??? Got problems???

 

[kennyd]

You are 100% correct Harry, I just used the hose because of the position of my QD's, it was easier to read the gauge.

 

[JimWalch]

Just a note for those who want to build a gauge setup:

You do not need the valve and "T", all you need is the gauge, a short piece of hose and a QD that fits one of your loader ports. You just plug in the gauge and operate the joystick to energize the port the gauge is plugged into. DO NOT HOLD THE JOYSTICK FOR A LONG TIME THOUGH as you are deadheading the hydraulic pump.

I know I didn't need a valve but the kid has lots of parts and energy to use up so that痴 what he made for me. Actually the valve part was a nice touch.

 

[dfkrug]

You don't even need the hydraulic hose. I just took the female QD off one of my loader hoses, screwed the gage into that QD, plugged it back onto the male QD from the valve.

That is how I do it. Just put the guage on any work port hose end
and operate the right valve handle.

This is a cheap and valuable diagnostic tool for all tractor owners.

I often find reliefs set too low, esp as a tractor ages and the relief
spring gets softer.

Do this test on the loader and you can verifiy the separate loader
relief is set correctly, too.

As for the hyd pumps, HST tractors will have a charge pump that
delivers only about 100-200 psi to the HST, and the HST's pump
(called an axial piston pump), which puts out more than 4000psi.
These are testable in addition to the implement/PS pump.

 

[hayden]

I just posted this note showing a pressure test set up and adjustment on a Grand L40

http://www.tractorbynet.com/forums/owning-operating/111787-pimp-my-tractor.html#post1278466

 

[lp333]

Hayden, thanks for the great post.