Have a problem with the hydraulics

[lzicc]

I have noticed lately that when using the BH, (BX22) the outriggers start to let up and I have to push them down again. It happens quite often. Also, when the bh is all pulled in, the bh and bucket and boom will start to droop as I am using the tractor. This happens allot and I have to pull in back up. I have also noticed the honking noise that the hydraulics make when you extended or retrack an implement too far also happens when digging when it is scooping up a load of dirt that is heavy. I have never noticed this honking noise to be that loud before. The honking gets allot louder after running it for awhile. It happens whether I am using the fel or the bh. This doesn't happen when the tractor is cold, only when it has been running for awhile.

It also seems like the tractor gets hot after using the hydraulics for while. I feel allot of heat coming from it. The temp gauge for the engine is ok and the tractor motor runs great. When driving the tractor, it runs fine, it's just the hyrdraulics that I have an issue with.

I changed the UDT fluid the other day along with the filter, changed the engine oil, filter and the air filter just to see if that would help. I also checked to make sure the plastic trans cooling fan was intact and it is. When digging for about an hour yesterday, the tractor seemed hot and the hydraulics seem to be running in slow motion, both the bh and the fel. If the fel would be up in the air with no load, it seemed to lower allot slower than normal after running the tractor for awhile. As I am lowering it, it almost seems like it is resisting and you can hear a slight buzz/honk noise as it is lowering. It is the same honk noise you hear while digging with it after it heats up, just very slight.

Not sure what to look for here. Like I said, when the tractor is cool, it runs great, it is only when the tractor runs for awhile that it does this. It seems like the hydraulic oil is getting to hot, but I don't know this for sure.

Any help would be appreciated.

 

[BrierPatch]

Are the hydraulics weaker the hotter or slower it gets ? Does your steering seem to be affected by it? What about the hydraulic screens/strainers. Doesn't seem likely, but you might want to check them/clean them.

 

[radioman]

I am not sure, but i think the releif valves needs shimming. Either that or the valves in manifold are leaking. Does your FEL still have issue with drooping when the power beyond is disconnected from BH and looped back in? knowing this answer will help you to look at the valve manifold on BH or start looking on the tractor.

 

[lzicc]

It does seem like the hydraulics are a bit weaker. It can be hard to tell since it seems to be moving slower. When I changes the trans fluid/filter, I did clean the strainer. There wasn't much on it. The steering doesn't seem to be affected. The dump on the fel seems fine, just the down seems slow and now that I think of it, it seems to raise slower.

I didn't try the loopback for the bh. I can test that.

 

[leonz]

You are sucking air into the hydraulic system.



The outrigger spools are bypassing and as the cylinders do not have pilot operated
valves they will droop over time and faster when loaded with the weight of the backhoe and tractor when it is elevated.

The oil for the backhoe is supposed get hot as the true "hydraulic oils"are designed to work at a hotter temperature.

A quick fix is to install a 2 way needle valves on the base fitting of the out rigger cylinder(s) barrel(s) to seal the oil path from returning to the spool(s) and just open them back up when you want to lower the tractor and move it.

These valves do not have pilot operated check valves as an integral part of the valve assembly so they all leak.

(1)it is entirely possible that the gear in that section of the pump may be
worn also affecting its performance and creating cavitation(air bubbles).
a. the pressure side of the valve bank may have a problem with inner hose partially blocking the oil path or it may be pinched.

(2) the relief valve may or may not have debris stuck in it

(3) the spring in the relief valve could be weak enough that it allows low
system pressure(the use of the back hoe at work) to return to tank.

(4) testing the system pressure at the "hot" operating temperature with a flow rater is the best way to find the problem.


The industry standard for testing pumps for flow and capacity is 1200 rpm
and 100 PSI as a base line measurement to determine the maximum flow rating and pressure that is tolerated beyond the pump.


If the oil flow sounds as if it is screaming/whining while working the back hoe the relief valve is bypassing to tank.

this will not solve the issue with the out riggers though and the needle valves will- unless the piston packings are very worn(dependent entirely on useage and packing quality)

 

[lzicc]

I called the dealer and they told me that they can do the test, but they would have it for a week. ?? I am thinking about buying a pressure gauge that I can at least test the pressure with.

Now today, it was a hot day and I ran the tractor digging with the fel pretty good and it ran fine. I ran it for a good hour or two and no problems. Even the honking wasn't there. Maybe a slight honk, (normal) but very unnoticeable compared to what I am used to. So it seems like when I use the bh, it's like the tractor is sitting still and not cooling off enough. When I was using the bh yesterday for a good hour or so with the tractor pretty much sitting still, that is when the issue started and both the bh and the fel would make that noise after the fact. Now today, it's fine. I know that doesn't mean anything about the out rigger issue, but the fel worked fine. When I first started the tractor up today, I made note of the out rigger position, and it hasn't really moved from last night.

It seems like to me, when I am using the bh for a while and the tractor is just sitting there running, it's like the trans oil is getting to hot. I don't get it.

 

[Lynxs1981]

Do you throttle up while using the BH?

 

[leonz]

A week *&^%^&*()_)(*&^%$%^&*()_!!!!!!!!!


Find a local hydraulics repair shop WITH A TEST BENCH AND A "SCHROEDER BROTHERS" OR "OTC" FLOW RATER and see about having it hauled there and ask them to flow rate the pumps 2 sections, and test the out rigger cylinders
for bypass on the test bench.

They should spend about 3-4 hours on it as long as its at thier shop, then you will know how screwed up it is. The less expensive quick disconnect fittings are always suspect because of the O ring seats.


Oh and by the way if they tell you it has to stay for a week find another dealer.



Please dont do anything with it, I dont want you to get your head blown off as the pressure gauge will only be proof enough for one function at a time.

 

[lzicc]

Yes, the throttle is up, I made sure of that.

Leon, that's a good idea seeing a hydraulics shop. They may be more willing to work for me at a better price.

 

[oldnslo]

If the loader is working fine it sounds like it may be in the BH controls. Did you by chance disconnect the power beyond hoses and reconnect them like Radioman suggested. If so one of them may not have been seated fully which could cause a restriction which would increase the heat load and reduce performance of all your functions.

Roy