m7040 busted hydraulic hose

m7040 · Oct 22, 2006

yesterday wile digging ot an old gas tank on the farm I busted a hydraulic hose for the FEL curl function. Lots of oil spray before I could shut it off.
Is that one of the hazards that needs to be cautioned against?
Think that slamming into the dirt with the bucket tilted caused too much pressure in the line and ruptured the hose.

MadReferee · Oct 22, 2006

Quite possibly. When you replace the hose make sure the new one is at least a 2-wire hose rated for 4000 psi or greater.

wushaw · Oct 22, 2006

It won't be your last, wear saftey glasses unless you have a cab.
I got sprayed three times with my previous tractor and all three times I had to wipe hydraulic oil off my saftey glasses.

N80 · Oct 22, 2006

I understand that pushing with the bucket in the down position puts tremendous pressure on the hydraulic system. I'm wondering (since I only have a cursory knowledge of hydraulics) why the pressure release valve didn't prevent this?

MadReferee · Oct 23, 2006

N80 said:
I understand that pushing with the bucket in the down position puts tremendous pressure on the hydraulic system. I'm wondering (since I only have a cursory knowledge of hydraulics) why the pressure release valve didn't prevent this?

Because there is no pressure relief on the work ports. When the spool is in the neutral position you have a mini-circuit between the spool's two work ports and the cylinder. Since fluid is blocked from exhausting when in neutral, something has to give. It's usually the hose but sometimes the valve actually cracks or splits open. A rather dangerous situation.

On most heavy equipment there is a relief on each work port, or at least those that have the potential for problems like the bucket curl. My dozer has reliefs on the bucket curl work port, the clam open and the clam close. But then again the breakout force on most dozers is pretty high, mine is 18,500 lbs.

m7040 · Oct 23, 2006

Thanks for the advice. I have a cab so it was safe but lots of oil all over. Dealer replaced the hose this morning on warranty so I am ready to install it. Think one needs to be careful with the curl function and keep it fairly level when applying force with 4 wheel drive. Seems it will break the hose if not. On my two wheel drive MF 203 loader it has not been a problem because I think the traction is more limited.

SkyPup · Oct 23, 2006

Using four wheel drive to push the bucket into the ground below a level angle will certainly result in blown hydraulic lines or a messed up FEL linkage. Often the rigid metal hydraulic pipes burst before the flexible rubber hoses go too. If you want to try to prevent or lessen the chance of this happening, use only two wheel drive.

I installed a hydraulic pressure gauge (0-5,000 psi) onto my L-3130 LA723 FEL control linkage adjacent to the dashboard so that I can see the hydraulic pressure all the time with a quick glance.

wushaw · Oct 23, 2006

m7040 said:
Thanks for the advice. I have a cab so it was safe but lots of oil all over. Dealer replaced the hose this morning on warranty so I am ready to install it. Think one needs to be careful with the curl function and keep it fairly level when applying force with 4 wheel drive. Seems it will break the hose if not. On my two wheel drive MF 203 loader it has not been a problem because I think the traction is more limited.

You must have a real good relationship with your dealer since hoses are not covered under warranty

m7040 · Oct 23, 2006

I did not know that hoses are not covered.

rdsaustintx · Oct 24, 2006

wushaw said:
You must have a real good relationship with your dealer since hoses are not covered under warranty

Mine was. Broke one on the FEL and dealer fixed it on-site.

Russell in Texas

m7040 · Oct 24, 2006

skypup, could explain how you connected the pressure gauge and what gauge and lines you used?

SkyPup · Oct 24, 2006

I took a standard Pioneer Quick Disconnect and tapped it for a Glycerin Filled Hydraulic Pressure Guage and then installed it inline with the high pressure line coming out of the joystick FEL controller.

I do not have a photo handy with me right now, but basically it is installed inline with the hose delivering the high pressure hydraulic fluid to the FEL lift cylinder.

Here is a photo of another person's setup for checking hydraulic operational pressure.

My setup looks just like this except that my gauge is inline with the high pressure hose going to the FEL, ie the high pressure hose exits the top of the guage.

This way, I always know what the pressure reading is at all times and can tell if something is amiss.

MadReferee · Oct 24, 2006

That gauge setup will do nothing when the spools are in neutral and you are pushing on something. If you really want to measure pressure on the lift or curl circuit you must have the gauge connected to the work port that you want to measure. Remember that each spool has 2 work ports and you should connect the gauge to the one that will have pressure against it.

SkyPup · Oct 24, 2006

I have mine measuring the lift circuit.

jrepp · Oct 24, 2006

M7040, at how many hours did your hose bust? I busted a FEL hose on my 5030 at about 20 hrs. Dealer replaced it under warranty. I now have over 1200 hrs of extremly heavy FEL work and have not had any more hose problems. I am just quessing my problem may have been a manufacturing defect?

m7040 · Oct 24, 2006

I had 90 hours on it when the hose burst. Truth be know it was my own fault for driving into the dirt with the bucket too much curled and this caused the pressure to build up in the line up to the spool valve and busted the hose that connected from the spool valve to the hard line on the loader. This is the one with the quick discennect on it. So lesson learned be careful when you have lots of traction with a curled bucket

N80 · Oct 24, 2006

Curled? I thought the problem occurred when the bucket was too far in the dump position? If the bucket is fully cureld it shouldn't put any pressure on the curl circuit (says the guy who knows nothing about hydraulics).