B21 loosing hydraulic performance

Silver Wings · Jun 18, 2018

My B21 has approximately 1600 hours (hourmeter broken) and it has served me very well. Most of the hours have been fairly easy homeowner type stuff, but over the last 2 years I've worked it hard removing 500 trees from my property (Sierra Nevada bark beetle kill). A lot of those hours it was working at it's absolute capacity to lift and carry logs (fork on the front). Over time I feel it's lost about 40-50% of it's capacity to lift, same applies to the backhoe. HST seems to be about the same as always...as far as speed and hill climbing. This winter it was having a problem with the hydraulic pump loosing prime. After sitting for a couple of days it would have no FEL or backhoe. I would loosen the 2 mounting bolts for the "flow priority valve" on top of the hydraulic pump and it would immediately prime itself and show no other signs of problems. I never did find a leak that would cause this and it hasn't done it for a couple of months now.

I think I've done a pretty good job of changing fluids and filters over the years. Last hydraulic oil change was 50 hours ago and included both filters and pick up strainer. This had no effect on hydraulic performance.

So...before throwing a $500 hydraulic pump at it, what should I be looking at for other possible causes? Keep in mind this has been a slow decline in performance. Looking forward to hearing your thoughts.

North Idaho Wolfman · Jun 18, 2018

Look for seeping leaks on the suction line.

But it could very well be a worn seals in the pump.

Silver Wings · Jun 18, 2018

North Idaho Wolfman said:
Look for seeping leaks on the suction line.

But it could very well be a worn seals in the pump.

There are none.

100 td · Jun 18, 2018

AS NIW mentioned, suction line leaks a high possibility.
Oring on top of hydraulic tank and "S" bend hose at pump inlet. Remove pipe and hose, check S bend for deterioration, and ensure no sideways strain on tank pipe replace oring.
Open the oil fill cap when running and inspect fluid for aeration

Silver Wings · Jun 18, 2018

100 td said:
AS NIW mentioned, suction line leaks a high possibility.
Oring on top of hydraulic tank and "S" bend hose at pump inlet. Remove pipe and hose, check S bend for deterioration, and ensure no sideways strain on tank pipe replace oring.
Open the oil fill cap when running and inspect fluid for aeration

I'll order a new O ring and "S" suction hose. Even if it turns out to be the pump I'd replace them anyway.
Thanks

100 td · Jun 18, 2018

Also check that the hydraulic selector valve for 3pt or hoe is fully selected/rotated.

100 td · Jun 18, 2018

A faulty QC or crap in the QC on the hoe could also be restricting flow. Disconnect hoe and check QC valves for debris, bypass hose with line and select 3pt on selector valve. Do not run without bypass hose in place. Check performance of FEL.

Silver Wings · Jun 18, 2018

100 td said:
A faulty QC or crap in the QC on the hoe could also be restricting flow. Disconnect hoe and check QC valves for debris, bypass hose with line and select 3pt on selector valve. Do not run without bypass hose in place. Check performance of FEL.

Do I need a bypass or can I just connect the 2 lines going to and from the backhoe to the 2 lines for the 3 point? They are the same type QC.

Silver Wings · Jun 18, 2018

100 td said:
A faulty QC or crap in the QC on the hoe could also be restricting flow.

If there were a restriction at one of the backhoe QCs would that also effect FEL performance?

100 td · Jun 18, 2018

Silver Wings said:
If there were a restriction at one of the backhoe QCs would that also effect FEL performance?

Yes, backhoe (take off) is inline with FEL prior to 3pt IIRC, can check hydraulic circuit. Just make a loop, so line out to hoe connects back to tractor, as if you didn't have the hoe on.

Silver Wings · Jun 19, 2018

100 td said:
Yes, backhoe (take off) is inline with FEL prior to 3pt IIRC, can check hydraulic circuit. Just make a loop, so line out to hoe connects back to tractor, as if you didn't have the hoe on.

I ran this test and there was no change in FEL lift capacity.
The suction hose has no outward signs of leakage, but it is original to the tractor and is stiff and a brittle feeling. I ordered a new one and O ring from Messick's. I will put them on and retest, if there is no change I suppose I'll bite the bullet on a new pump. Thanks for the help.

Any other thoughts???

Who do folks here like for online parts? Any deals available on filters? My closest dealer is 55 miles away, so online is preferred.

I'm glad I came here, great forum with lots of good info!

North Idaho Wolfman · Jun 19, 2018

Before you jump on getting a new pump do a pressure test on the system.

100 td · Jun 20, 2018

Silver Wings said:
Over time I feel it's lost about 40-50% of it's capacity to lift, same applies to the backhoe.

Hopefully you've just gotten used to it and it still lifts a bucket of dirt!

Kennyd4110 sells gauges, other may do, plus local suppliers, online etc, or others available as noted here.
http://www.orangetractortalks.com/forums/showthread.php?t=33668&highlight=gauge
If your pressure is up to spec, or you want to do another couple of checks, here are some specs.
ASAE rated lift 420kgf 926lbs
Relief 2000 psi
Raise to full height 3 sec
Lowering time (Float down) 1.8 sec
Roll-back time 2.6 sec
Dumping time 1.7 secs
Flow through priority valve approx 7.1 GPM (US)

Backhoe
Boom extend 4.1, retract 3.4
Dipper extend 3.6, retract 2.8
Bucket extend 2.6, retract 1.9

If you have something solid you can get your bucket under you can try to lift and see if you can get the relief to operate.

Silver Wings · Jun 20, 2018

100 td said:
Hopefully you've just gotten used to it and it still lifts a bucket of dirt!

When I said "feel" I was referring to the 40-50% loss, the guesstimate was on the percentage. I'm 100% certain it does not have the capacity it once did. I thank you for the help. I'll get a set of gauges and see where it's at and go from there. Can anyone help out with a link to doing a test on the B21? I'm really an amateur when it comes to hydraulics

North Idaho Wolfman · Jun 20, 2018

Silver Wings said:
When I said "feel" I was referring to the 40-50% loss, the guesstimate was on the percentage. I'm 100% certain it does not have the capacity it once did. I thank you for the help. I'll get a set of gauges and see where it's at and go from there. Can anyone help out with a link to doing a test on the B21? I'm really an amateur when it comes to hydraulics

Does that model have quick disconnects on the loader on the line that feed the cylinders?
If it does it's just a matter of disconnecting one installing a gauge with a quick disconnect on it and test the pressure.

Silver Wings · Jun 20, 2018

North Idaho Wolfman said:
Does that model have quick disconnects on the loader on the line that feed the cylinders?
If it does it's just a matter of disconnecting one installing a gauge with a quick disconnect on it and test the pressure.

Like I said...I'm an amateur here, so bear with me on terminology and questions.

From the FEL control block there are 4 lines, no QCs. I'm sure I can figure out how to adapt in a gauge. My questions are:
Should the gauge be T'd into the line so as not to block flow?
Which Line? Hoist cylinder or tilt cylinders?
What about flow?
If I find PSI within spec, but don't have capacity I would assume restricted flow. How and where do I test for that?

North Idaho Wolfman · Jun 20, 2018

Silver Wings said:
Like I said...I'm an amateur here, so bear with me on terminology and questions.

From the FEL control block there are 4 lines, no QCs. I'm sure I can figure out how to adapt in a gauge. My questions are:
Should the gauge be T'd into the line so as not to block flow?
Which Line? Hoist cylinder or tilt cylinders?
What about flow?
If I find PSI within spec, but don't have capacity I would assume restricted flow. How and where do I test for that?

Yes you could tee into it, it doesn't really matter, you'll just have to run the cylinder to the end to get a total reading.

Any of the 4 lines will work, but the bucket lines are easier, you won't have to lift the loader all the way up to get a reading.

Flow is a whole other test and there is no cheap way to test that.
Flow is only going to effect implement speed, not power.

100 td · Jun 20, 2018

Sent you a PM

Silver Wings · Jun 27, 2018

Update: New suction hose and O ring arrived late yesterday. I then put the fork attachment on the front and loaded it with logs to the point that it would just lift the load. At 2600 rpm it would only lift that load 14" in 12 seconds. After replacing the suction hose and O ring this morning it lifted the same load to max height in 9 seconds! I think we got it! Although I did not pressure test the pump and I'm unsure of the exact weight used in my test, I do feel confident that we are back in the ball park and that the pump is good. You've gotta love a cheap and easy fix!

Many thanks to 100td and North Idaho Wolfman for the help, it is very much appreciated!

North Idaho Wolfman · Jun 27, 2018

Excellent to hear!

B21 loosing hydraulic performance

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