9540 Burst Hydraulic Line

[jdavis7399]

I was running a grapple on my M9540 using the loader third function. At about 1200 RPM when the grapple reached its maximum open position I heard a pop and found that I had burst a metal hydraulic line located near the pump under the right rear of the tractor. I was surprised because I thought the tractor and most tractors had a high pressure relief valve to bleed off pressure after about 2700 PSI.

Hydraulics are not my strong point. Should this have happened? Is it operator error or a defect? Has it happened to anyone else?

 

[leonz]

I was running a grapple on my M9540 using the loader third function. At about 1200 RPM when the grapple reached its maximum open position I heard a pop and found that I had burst a metal hydraulic line located near the pump under the right rear of the tractor. I was surprised because I thought the tractor and most tractors had a high pressure relief valve to bleed off pressure after about 2700 PSI.

Hydraulics are not my strong point. Should this have happened? Is it operator error or a defect? Has it happened to anyone else?

The relief is located on the valve body in most instances and pumps have no immediate relief valves exiting the pressure side of the pump, Whoopsie!!!!!

The pressures generated at the implement eventually back up the valve and relief but you should not have a blown pressure line at the pump unless the relief stuck shut or:

Also if the valve spool was able to totally block the fluid flow (which it should not have) you have a bad control valve or a relief thats improperly set.

 

[jdavis7399]

Thanks, the dealer indicated there may be a design problem with the line since the replacement part has been redesigned. It also looks like the repair will be covered by warranty.

 

[rjkobbeman]

I was running a grapple on my M9540 using the loader third function. At about 1200 RPM when the grapple reached its maximum open position I heard a pop and found that I had burst a metal hydraulic line located near the pump under the right rear of the tractor. I was surprised because I thought the tractor and most tractors had a high pressure relief valve to bleed off pressure after about 2700 PSI.

Hydraulics are not my strong point. Should this have happened? Is it operator error or a defect? Has it happened to anyone else?

Has not happend to me, however I did install my own 3rd function. One thing I noticed was one of the metal lines, in the location you described, were hard to install. It was a "perfect fit" and required a little flexing (not bending) in order to "pop" it into place. (Remember, the metal fittings have a curve/bell end on them.) The fittings that this metal line attached, on both ends, were fixed in place -- they were metal as well and not flexible hose. Anyway, I can see if someone was not carefull during the install they could damage the line.

Maybe your blow out is the result of a bad installation? The "redesign" might make the install easier and less likely to get damaged during installation. I'm just guessing here... I have no proof of anything I am saying.

 

[crazyal]

My guess it was just bad or weakened when installed like rjkobbeman said. I've my fair share of lines burst but it's always been from one thing, they were weakened. Sometimes just from old age but more likely from rubbing on something. I've had fittings pop when something hit them and did some damage. If the relief valve didn't kick in I'm thinking the tractor would stall being at such a low RPM before bursting a pipe.