YW-6 Backhoe Problem

[erj]

TruChaos,
I want to be sure that I understand. We have now moved from a dropping bucket when not in use on 10/6 to a backhoe not operating properly?
When was the last time that the backhoe worked properly (aside from the boom drop when not in use) and have you done anything to the tractor since that time?
RonJ

 

[TruChaos]

It was working fine other than the drooping boom when I made the first post for this thread. Now the entire backhoe has no power.

Just for a moment to see if it made a difference, I switched the PTO to 1000 to see if there was a change in power and there was no affect. This was less than 10 seconds.

I wanted to drain the fluid and check the screen today but ended up doing other jobs.

If the screen is clear and the pump is ok, where is the relief valve you mentioned? Also is there a screen at the main connection point on the control mechanism? In other words the point there the pressure line from the pump connects to the control?

 

[Bob Rooks]

My guess is that pieces of your boom cylinder seal have found their way to the relief valve. There are no internal screens or filters on this machine other than the in-tank suction strainer unless you have installed them yourself.
Sitting in the seat, with the top of the console removed, the relief valve will be on the left side of the valve stack or, trace the hose from the discharge side of the pump to the valve stack. That's where the relief valve is.

 

[TruChaos]

My guess is that pieces of your boom cylinder seal have found their way to the relief valve. There are no internal screens or filters on this machine other than the in-tank suction strainer unless you have installed them yourself.
Sitting in the seat, with the top of the console removed, the relief valve will be on the left side of the valve stack or, trace the hose from the discharge side of the pump to the valve stack. That's where the relief valve is.

Got it. Thanks!

 

[erj]

If you are interested, send me your Email address in a PM. I can send you a PDF file showing the disassembly, etc of the relief valve on the JW03. I suspect that it is the same as yours.
RonJ

 

[TruChaos]

If you are interested, send me your Email address in a PM. I can send you a PDF file showing the disassembly, etc of the relief valve on the JW03. I suspect that it is the same as yours.
RonJ

I sent you a PM with my email address.

Thanks!

 

[TruChaos]

Today I drained the hydraulic fluid and cleaned the tank screen. The fluid looked good and the screen was clean with a few round pieces of grit (normal). There wasn't any bits of rubber or anything that looked like it may have been a part of any failing component. I replaced the fluid with AW46 but didn't have the time to test it tonight. I'll check it tomorrow and begin disassembling the relief valve. It sure sounds like that is the problem.

Does anyone sell Chinese Tractor Viagra (relief valve rebuild kid) to solve the limp boom problem?

Also I have a spin on suction screen assembly does anyone make a hose kit for these or do I have to go down the street and get robbed by the worlds most expensive custom made hydraulic line shop? It looks like the existing hose might be a bit short.

It would be nice to be able to change/check the filter without draining the oil tank every time.

 

[RonMar]

Does anyone sell Chinese Tractor Viagra (relief valve rebuild kid) to solve the limp boom problem?.

Short of something being broke, it only has "O" rings inside... IT may be out of adjustment, but youwill have to fit a pressure gauge to confirm or reset it...

Also I have a spin on suction screen assembly does anyone make a hose kit for these or do I have to go down the street and get robbed by the worlds most expensive custom made hydraulic line shop? It looks like the existing hose might be a bit short.

It would be nice to be able to change/check the filter without draining the oil tank every time.

If I were going to the trouble of fitting a spin-on filter, it would be on the return line to the reservoir. OH, wait, that is just what I did Hydraulic pumps push better than they pull. because of that they typically require a larger mesh filter, usually about 150 micron, that won't impede that weak suction force. A filter on the return side to the reservoir with oil being pushed thru it, is typically down to the 10 Micron range. If you think about it, if you are carefull with what you dump into the tank, and put an air filter on the tank air vent, there should be nothing in the tank to do any harm. That leaves any potential debris comming from the plumbing/system itself. If you put a fine return line filter on the line right before the tank, it will catch any debris from a failing system component, and keep the tank clean...

I Installed a 11GPM buyers spin on boss and internally relieved filter. It is installed after the valve on the way back to the reservoir, so no high pressure fittings or special lines required. 2 hose barb fittings, the screw on filter boss, cut the return line where you want the filter, plug the thing together with hose clamps and "Bobs your uncle"

Just curious, why AW46 and not AW32?

 

[traktorz]

Just curious, why AW46 and not AW32?

According to the information from the Agrol oil vendor:
There is a general rule of thumb, that it's always better with using a higher viscosity than too low dito.

Table of temp range versus viscosity for hydraulic oil

 SH 15  -29 C - +50 C 
SHS 32  -25 C - +75 C 
SHS 46  -15 C - +90 C 
 SH 68   -5 C - +90 C

You can also see that the ISO VG 46 resists high temperature much better than the ISO VG 32. That's the prime reason of choosing the higher viscosity oil here.

The only reason to use ISO VG 32 is when below freezing point, below 0 Centigrades. Backhoes are seldom used when the soil is frozen, so ISO VG 46 is therefore the better choice.

Actually never seen any recommendation of using ISO VG 32 for a backhoe, rather common STOU (Super Tractor Oil Universal) oil sometimes are recommended.

 

[Bob Rooks]

According to the information from the Agrol oil vendor:
There is a general rule of thumb, that it's always better with using a higher viscosity than too low dito.

In all of my years of dealing with lubrication issues, I've never heard of such a thing. I went to Agrol's website and found I had to be bi-lingual. I personally know lubrication engineers and that has never come up.