B3000 loader boom not raising

[bandit67]

Ok, I'm stumped. Last weekend, after running my flail mower for a couple hours, my loader boom stopped being able to raise after I finished mowing. All other functions are working fine - loader boom lower under power, bucket curl & dump. When mowing, I do have to raise & lower the loader often to get around trees, etc, and all was fine while mowing. Initially, the loader boom raise issues were a bit sporadic, but I could not duplicate exactly how to fix the issue. It started out that if I dropped the loader all the way to the ground in float mode to remove any line pressure, I could then raise the boom back up, but that "trick" doesn't seem to be working on a regular basis. Hydraulic fluid did not seem to be too hot, as I've noticed in the past (odor) while running the backhoe for a few hours on a hot summer day.

I can get the loader boom to raise only occasionally, but there seems to be no rhyme or reason behind what works to "reset" and what doesn't. I checked hydraulic fluid level, and it was fine. Hydraulic fluid is still about as clear as when it was last changed at 100 hours. Machine has 175 on it now, and is not due for fluid or filter change quite yet.

When the issue occurs, the loader valve seems to go into bypass mode, like you hear when the boom is raised all the way to the top before releasing the joystick. The boom will raise about a half inch up the hydraulic ram, then stop and go into bypass mode. No change removing 3pt implement (wondered if the load and the 3pt valve may have been affecting things).

While messing with it this morning, I did get a leak at both boom ram fittings at the same spot on each of the hydraulic lines at one point, and thinking that was the problem, I wiped the fittings off to determine exactly where the leak was, and then no more leak. That one instance today was the only time I have found any hydraulic leaks over the last 2 weekends worth of messing around with it.

I unplugged the hydraulic fitting at the loader valve just in case there was something going on there, but that didn't appear to be the problem. Also checked the rear fitting at the back where I hook up the backhoe. Backhoe has been off since last fall. Loader has only been off the machine once a few years ago after I got it, just so I could say I've taken it off at least once.

Any suggestions?

I've included a couple pics of the one-time fitting leak that I so far have not been able to duplicate. The leaks (onto the tires) happened after lowering the boom to raise the front tires off the ground and then was able to raise the boom. Subsequent sporadic rasing (when I can manage to get it to go up) and lowering of the boom has not duplicated the leak.

Was going to try to make an adjustment to the loader boom cable going from the cab joystick to where it enters the loader valve, as that's the only adjustment on that one, but since I can actually get the loader function to work properly every so often, I'm not sure that adjustment would help.

 

[KennyV]

AT the Quick Connects, switch the hoses from the boom to the curl and the curl to the boom circuit... see if the problem switches. KennyV

 

[bandit67]

OK, so switching boom raise and boom lower QC's at the loader valve, switches the "issue" to boom lower. So it guess it's either a cable adjustment or the loader valve internals. I guess the cable may have stretched enough to cause this issue, but with the sporadic nature of it, not sure, but worth investigating further before looking at the loader valve itself.

I have a B3000 Workshop Manual, but there is nothing on the loader control valve. LA403 Assembly Manual does not have valve breakdown in it. Not sure if I can get instructions on breakdown/repair of the loader control valve, or if I'll end up needing to purchase a whole new valve if that ends up being the problem.

 

[aczlan]

OK, so switching boom raise and boom lower QC's at the loader valve, switches the "issue" to boom lower. So it guess it's either a cable adjustment or the loader valve internals. I guess the cable may have stretched enough to cause this issue, but with the sporadic nature of it, not sure, but worth investigating further before looking at the loader valve itself.

Save yourself some time and replace the quick connects on the tractor side of the boom circuit. Probably one or both of them is not opening properly and is acting like a check valve rather than a quick disconnect.
Much cheaper and faster than tearing into the loader valve and it's probably where your problem is.
There is also a possibility that it could be the loader side quick connects, if you switch the boom raise and lower hoses to the bucket curl and dump quick connects on the tractor side, that will let you rule the loader side quick connects out in a couple minutes.
Aaron Z

 

[bandit67]

OK, thanks for the heads-up on the fitting testing. I'll look into that and report back.

 

[aczlan]

OK, thanks for the heads-up on the fitting testing. I'll look into that and report back.

I point this out because I had a male fitting go bad on the baler (we borrow the one of the plow cylinders off of the BX2660 to angle the kicker chute) and it wouldn't let me angle the chute.
Took me almost 2 hours to get it figured out...

Aaron Z

 

[bandit67]

So it looks like the male fitting on the loader valve may be the problem. The poppet does not return straight after it is pushed in, it twists a bit so does not seat properly, so I have to assume, and hope, that is the issue, instead of a problem with the loader valve itself. Frustrating, as I only have removed the loader once, so it appears that the fitting failure is simply a result of loader use.

I'm considering replacing the fittings with skid steer style fittings, hoping even at that small size, they are more durable than the ISO 7241 B fittings.

 

[aczlan]

So it looks like the male fitting on the loader valve may be the problem. The poppet does not return straight after it is pushed in, it twists a bit so does not seat properly, so I have to assume, and hope, that is the issue, instead of a problem with the loader valve itself. Frustrating, as I only have removed the loader once, so it appears that the fitting failure is simply a result of loader use.

I'm considering replacing the fittings with skid steer style fittings, hoping even at that small size, they are more durable than the ISO 7241 B fittings.

I would just replace the bad one. Our B7500 is 14 years old with 1200ish hours and we haven't replaced one yet. We had one from the BX2660 go bad, but the other three have been fine.

Aaron Z

 

[bandit67]

Replaced the the male fitting with the problematic poppet at the loader control valve. Unfortunately, that did not fix the issue. Will replace the female fitting and see what happens.

I'm afraid the issue may end up being the loader control valve, though.

 

[aczlan]

Pull both male fittings​, stick a hose in each side and see if fluid flows out of both sides.

Aaron Z

 

[bandit67]

FINALLY!!!!!!

I finally figured out the issue with my FEL boom not raising properly. I realized what was going on a week ago when I removed the FEL just to see how the machine handled mowing chores with the flail. I always figured the weight of the FEL would help balance the tractor a little better (it does) so the FEL has always been on for mowing duties. When I was finished mowing, I brought the machine down to the garage to blow all the dust off, and found hydraulic fluid had been dripping from one or more of the factory male QC poppets at the loader valve. The poppets were not seating properly, and were allowing hydraulic fluid to continue to flow through the QC's, regardless of FEL joystick position, thus creating a constant "bypass" situation at the valve.
I replaced all 4 complete factory QC assemblies today, and now I can't get the boom raise function to "fail", so I think the problem has finally been resolved for good.

Interesting part is that prior to these issues starting, the FEL had only been removed from the tractor once back when I first got it, just to do it. I would have figured repeated QC disconnects and reconnects would be harder on the poppets & springs than normal FEL operation, but I guess not. I just did the 200 hour service a couple weeks ago. This loader issue started about a year ago, closer to the 150 hour mark. I just never had time, or remembered, to look into it when the weather was good, since the majority of FEL use the last couple years has been for snow removal. Failed poppets so soon sure seems a bit odd compared to previous machines I've owned.