B21 Low Loader Breakout Force

[PointyHairedBoss]

I have a B21 with about 1900 hours - great little machine.
Recently my loader bucket tilt (I think that's called "breakout force") has become very under powered. I can barely scoop a half load of gravel. Bucket lift works fine.
When I tilt the bucket under load I get a hissing sound in the valve like fluid bypassing.
Any suggestions?

 

[Dave M7040]

Go to a Princess Auto location and buy a pressure gauge good for 0 to 3500 psi along with a male hydraulic coupling fitting compatible with your tractor's.
the gauge is $16.
0 to 3,500 PSI Glycerine Filled Pressure Gauge | Princess Auto
Install the gauge into a rear hydraulic port if you have one or into the one for the loader.
Rev up the tractor, activate the hydraulics and see what pressure shows on the gauge.
If it is around 2,500 to 2,700 psi then there is nothing wrong with your tractor.
If is is lower value then an adjustment is required which is best left to the dealer because your system likely has two relief valves to protect the hydraulic system. There is one relief valve for the 3 pt hitch and rear remote(s) and another for the loader and both need to be set.
If you have a joystick control it is possible that a cable has lost its adjustment and is not opening the valve for the loader all the way.
The gauge and fitting purchase with you doing the test is by far the cheapest first step.
Dave M7040

 

[PointyHairedBoss]

Thanks Dave,
Nearest Princess Auto is 2 hrs away so it will have to wait for next trip.
The hoe feels like it has full power so I suspect it is more likely to be the relief valve for the loader than the system pressure. I looked at the parts list for the loader joystick valve & didn't see anything labelled "relief valve". Is the relief valve for the loader located inside the control valve? The hissing noise I hear sounds like it is coming from the control valve.

And Ill check the valve for adjustment once it stops raining.

 

[Dave M7040]

Thanks Dave,
Nearest Princess Auto is 2 hrs away so it will have to wait for next trip.
The hoe feels like it has full power so I suspect it is more likely to be the relief valve for the loader than the system pressure. I looked at the parts list for the loader joystick valve & didn't see anything labelled "relief valve". Is the relief valve for the loader located inside the control valve? The hissing noise I hear sounds like it is coming from the control valve.

And Ill check the valve for adjustment once it stops raining.

Local hydraulic shops will have the gauge and coupling fitting for about the same cost as Princess.
Post a picture of the loader valve and I may be able to comment.
Since the same pump serves both the hoe and FEL and each of the relief valve are on the same circuit just close to the devices they serve, if one is blowing at too low a pressure I would expect it would keep the pressure of the hoe from building up to proper levels as well.
Trying to trouble shoot a hydraulic problem without a pressure gauge is like trying to determine how serious your child's fever is without a thermometer.
Even if you found the relief valve for the FEL, how would you know how much to change it?

Dave M7040

 

[downsizingnow48]

I don't have my owner's manual handy but I have looked this up before. I believe the B21 system pressure is in the range of 2100 psi.

 

[PointyHairedBoss]

Local hydraulic shops will have the gauge and coupling fitting for about the same cost as Princess.
Post a picture of the loader valve and I may be able to comment.
Since the same pump serves both the hoe and FEL and each of the relief valve are on the same circuit just close to the devices they serve, if one is blowing at too low a pressure I would expect it would keep the pressure of the hoe from building up to proper levels as well.
Trying to trouble shoot a hydraulic problem without a pressure gauge is like trying to determine how serious your child's fever is without a thermometer.
Even if you found the relief valve for the FEL, how would you know how much to change it?

Dave M7040

Here are some photos of the valve.

 

[Rod in Forfar]

My neighbour found a small Allen screw to adjust the remote on my B7510. It was hidden in a plain cylinder. In your case I would lie down under the valve and look up to see if there's a little Allen screw in view.

 

[Dave M7040]

I have a B21 with about 1900 hours - great little machine.
Recently my loader bucket tilt (I think that's called "breakout force") has become very under powered. I can barely scoop a half load of gravel. Bucket lift works fine.
When I tilt the bucket under load I get a hissing sound in the valve like fluid bypassing.
Any suggestions?

A simple test would be to to reverse the hoses temporarily. Connect the loader arms to the bucket and the bucket to the loader arms. See if it acts the same. Make the change at the valve or if there are quick couplings even better.
Dont try to use this configuration for any high work or you are apt to get hurt because nothing will be natural. I have seen old farmers suffocate when a large bail of hay rolled back unto them on the seat. They had reconnected the hoses incorrectly and continued to user their tractor`s FEL.
Dave M7040

 

[PointyHairedBoss]

I solved my problem. First I ordered a pressure gauge, hose & fittings from Princess Auto on line. This was my first time ordering from them. The web site is easy to use & delivery was quick - highly recommended.
I found some info in the tractor / loader manuals about how to check the pressure which I did. The relief valve was opening at about 1000 psi, correct setting is around 2000. No wonder I had no power.
The next step was to adjust the relief valve which is also described in the manual. The relief valve for the loader valve block is located under the seat on the right hand side in a very tight space. It was very dirty & looked like it might be seized. I thought this was probably the first time it had to be adjusted for the 10 year old machine so I was pleasantly surprised when the lock nut loosened & the valve stem could be turned freely. After a couple of adjustments I got the relief pressure back up to about 2000 & my loader back in operation. In case anybody has to make this adjustment, you turn the valve stem clockwise (if you were looking at the end of the stem) to increase the pressure. It doesn't take much movement for a fairly large pressure change. I think I turned mine less than one revolution to go from 1000 to 2000 psi.

 

[troutsqueezer]

Thanks for reporting back!