B 26 backhoe running slower and slower

[westcliffe01]

Just to comment on a similar problem I had with my Superstav (badge engineered and called a Bobcat B200)

When I bought the unit it had been a rental, has 1300 hours on it. The backhoe specifically had been used most, some of the pins were worn and some of the bucket teeth were loose, the hoses leaked and the renters had torn up the 1/8" thick guards over the stabilizer cylinders using the bucket teeth....

Anyway, I started doing maintenance on it a bit at a time (bought in 2009 and I have put 200 hours on it since, so it is not in use every day). Last year I replaced all the hoses on the backhoe and lost a lot of fluid in the process and decided I needed to replace all the hydraulic fluid and the pickup screen and filters in the tank. I did not have a spec on the oil and got general purpose hydrostatic fluid at TSC.

When operating the machine without actually "working" everything appeared normal. But the first time I had to do any serious digging with the hoe I was struck with how feeble it was. As summer wore on I did a lot of work with the loader and I noticed that as the machine heated up, the loader became increasingly feeble too.

After a lot of digging and checking I finally concluded that the biggest common factor was the 15 gal of new oil I put in it. Checking into that oil, I discovered that the generic hydrostatic fluid is SAE10 viscosity. I read through every page of the factory manual for the machine and finally right at the back discovered that the oil used in the system was a multigrade 15-40 or 20-50 in other words basically engine oil. Holy moley..

So after that lesson, I drained the tank again (an expensive flush) and gave the fresh oil to the farmer for one of his ag tractors from the 1940's.. Then filled it with 15-40 multigrade. Obviously some of the lighter oil was still held in the various cylinders on the machine, but the performance improved immediately.

The hydraulic system on my machine happens to be laid out for 5000psi working pressure, not like some ag systems. So this system really needs heavier oil or else the internal leakage in the pumps is excessive. I will probably have to do another partial drain this year when I work on replacing some of the balance of the hydraulic hoses that seem to be at the end of their useful life (it seems working at 5000 psi if not conducive to long life) so that should help get rid of a bit more of the lighter oil that was left in the system.

This may not be your issue, but it had me really concerned for quite a while. After correcting things, both the hoe and loader are capable of lifting the machine clear off the ground, so it was not a hardware issue.

 

[J_J]

westcliffe01 ,

Can you possibly take a relief valve reading. Just curious if the hyd system can sustain pressure over 3000 psi.

What is the pressure rating on the hoses on your machine?

 

[Gary Fowler]

westcliffe01 ,

Can you possibly take a relief valve reading. Just curious if the hyd system can sustain pressure over 3000 psi.

What is the pressure rating on the hoses on your machine?

I haven't checked for pressure gauges other than local shops and no one carries them, even the Kubota dealer didn't carry any. I suppose I could go to the BXpanded website and pay triple for them.
A quick question on the relief valve, If I get a gauge and a flowmeter to do the work myself, does anyone have a set of instructions on 1) how to remove and set the PRV for the right pressure, everything is screwed in upside down and I don't know what all is going to fall out when I unscrew the valve (2 How to set up the flow meter with pressure gauge to see the GPM output.
If you take off the PRV will the hydraulic lines loose pressure or do the valves hold everything. One of the reasons I am hesitant to work on it is that I don't have any thing to block up the tractor with and it would have to be up pretty high to be able to get underneath it to get to the PRV. I have some HF jack stands but I don't know if I would trust my live to them to hold.

 

[Gary Fowler]

If I were you I'd pay close attention to what J J said about how the controls may be tied to a certain hose orientation from the factory. And until you commit to having someone test the flow and relief settings you'll never solve this problem. If you're possibly doing damage to your pump now by running the hoe at high fluid temps and possibly restricted flow, (clogged screen?), you may end up killing the pump and incurring big expenses in the long run.
Forget the first dealer- they ignored what you asked for and billed you to smash rocks on their lot for an hour?! AND they re-oriented your lines to how they were supposed to be from the factory- which now may make sense based on what J J said.
If it were mine I'd find a dealer or local hydraulic shop equipped and knowledgeable about tractor hoes and pay them to do the tests, NOW, not later, and figure out what is wrong. Short $ now- or long $ later.
This problem will not solve itself. Your hoe is trying to tell you something- you need to listen to it and fix it:thumbsup::2cents:

First off, it has been set this way (excavator style for levers) since new and it worked fine for first 200 hours or so. I don't really see how swapping the hoses from SAE setup to ISO set up would damage anything as one runs the boom and other the dipper so not much difference in pressures and flow requirements, certainly shouldn't be any restrictors in those lines, perhaps it should have some in the swing as it moves a tad too fast for my needs.
I will look to take the machine to the other Kubota dealer in HOPE Ark. soon. I just don't relish the idea of loading and hauling it in windy, rainy, snowy conditions and when we have had a few good warm sunny days, I always seem to find other things to do that are more important. March here usually has some nice spring days so I will see what comes. I will of course let everyone know when I get it worked on what the outcome is.

 

[J_J]

A short hose, this 3000 psi hyd gage, and a QD to match your tractor, or a gage screwed into the QD.. About $30.

Surplus Center - 3000 PSI 2.5" LF LM GAUGE

 

[EE_Bota]

I haven't checked for pressure gauges other than local shops and no one carries them, even the Kubota dealer didn't carry any. I suppose I could go to the BXpanded website and pay triple for them.
A quick question on the relief valve, If I get a gauge and a flowmeter to do the work myself, does anyone have a set of instructions on 1) how to remove and set the PRV for the right pressure, everything is screwed in upside down and I don't know what all is going to fall out when I unscrew the valve (2 How to set up the flow meter with pressure gauge to see the GPM output.
If you take off the PRV will the hydraulic lines loose pressure or do the valves hold everything. One of the reasons I am hesitant to work on it is that I don't have any thing to block up the tractor with and it would have to be up pretty high to be able to get underneath it to get to the PRV. I have some HF jack stands but I don't know if I would trust my live to them to hold.

I like my BXPANDED gage. Costs come in all forms.
No one cares where you get a gage, only that you begin to report pressures to the resident experts so that they can help.

 

[Gary Fowler]

Well I ordered the gauge and maybe it will be here in a week or less. Will see how that goes and if I need to do a flow test.
I just used the TLB to dig a hole to bury a calf and it worked ok for that. I think it is just getting weak when the oil gets hot or maybe the oil gets hot because it is by-passing. I will check it when I get the gauge ($16.95 for the gauge and $12.95 to ship)

 

[Jaylegger]

Perhaps this has no bearing on backhoe operations for this particular tractor but is there a chance the 3-point hitch lever is partially engaged?

 

[westcliffe01]

All the hoses and fittings on my machine are 5000psi "working" pressure rated. I had a heck of a time finding the DKOL crimp fittings (and the proper hose for them) but eventually I found a supplier in California that had it and a chart for the crimp diameters for all the different size fittings and were very reasonably priced.

There are many things about these european machines which are not the same as the equipment we are familiar with, and the oil just happened to be one of them.

westcliffe01 ,

Can you possibly take a relief valve reading. Just curious if the hyd system can sustain pressure over 3000 psi.

What is the pressure rating on the hoses on your machine?

 

[Coyote machine]

First off, it has been set this way (excavator style for levers) since new and it worked fine for first 200 hours or so. I don't really see how swapping the hoses from SAE setup to ISO set up would damage anything as one runs the boom and other the dipper so not much difference in pressures and flow requirements, certainly shouldn't be any restrictors in those lines, perhaps it should have some in the swing as it moves a tad too fast for my needs.
I will look to take the machine to the other Kubota dealer in HOPE Ark. soon. I just don't relish the idea of loading and hauling it in windy, rainy, snowy conditions and when we have had a few good warm sunny days, I always seem to find other things to do that are more important. March here usually has some nice spring days so I will see what comes. I will of course let everyone know when I get it worked on what the outcome is.

I'm not looking to argue with you or p@#s you off; merely seeking to light the fire that gets you to take it over to the other dealer and get it checked out. You state that it worked fine for 200 hours- so what happened then? Did something change?
Does the possibility that the hoses were installed other than factory design for your hoe present any credibility to you regarding the possibility that this could have caused the current problem over the 200+ hour timeframe?
If it were me, I'd certainly want to check this line of thinking out with your next dealer, at least to finally rule it out as a possible cause. You don't really have anything else, other than a possible flow restriction/over/under/pressure setting to consider do you?