I have a Komatsu D37P-5A and the angle cylinder no longer works. When I try to angle the blade right or left, the blade makes a very short jerking motion (an inch or less )in that direction, but will not move as it should. If I put the blade against a tree and push, I can get it to angle. The tilt and lift cylinders work as they are supposed to. Any help is greatly appreciated.
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Angle cylinder doesn't work
- Thread starter Tommy
- Start date
325 n counting
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- Mar 23, 2014
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- Heavy equipment operator,do some pipe fitting as w
possibly blown cylinder packing ?
g_man
Senior Member
I am not a mechanic but this is what I would do.There is probably an easier way but this works. All you need is some plugs and a pressure guage.
You need to figure out if it is the valve or a cylinder. I would remove the four hoses from the angle cylinders and plug 3 of the hose ends with a proper plug fitting ( like a JIC-8 male maybe ). I would put a pressure guage on the 4th hose end. Operate your valve to angle the blade in the direction that would put pressure on the gauge. If you see pressure ( like 2000 psi ) on the guage and you here the pressure relief go off then your valve in that direction is good. Switch the guage to the other hose on that side and check the valve in the other direction.
If the valve is good then then it must be a cylinder. But which one ?
Connect up the hoses to one cylinder. The one on the other side from the guage. Leave the guage where it is. Operate the valve to angle the blade. If that cylinder and the valve are good the blade will angle in both directions and the pressure relief should go off when you hit the stops. You should see the 2000 psi or so when you hit the stop in the direction that puts pressure on the guage. Note: oil will shoot out of the open cylinder ports if it has not already drained out when you took the hoses off. Switch everything to the oter side to check the other cylinder by itself. You should now know where your problem is assuming nothing is bent and fluid can return to the tank because you can angle the blade by pushing on a tree.
Good luck.
You need to figure out if it is the valve or a cylinder. I would remove the four hoses from the angle cylinders and plug 3 of the hose ends with a proper plug fitting ( like a JIC-8 male maybe ). I would put a pressure guage on the 4th hose end. Operate your valve to angle the blade in the direction that would put pressure on the gauge. If you see pressure ( like 2000 psi ) on the guage and you here the pressure relief go off then your valve in that direction is good. Switch the guage to the other hose on that side and check the valve in the other direction.
If the valve is good then then it must be a cylinder. But which one ?
Connect up the hoses to one cylinder. The one on the other side from the guage. Leave the guage where it is. Operate the valve to angle the blade. If that cylinder and the valve are good the blade will angle in both directions and the pressure relief should go off when you hit the stops. You should see the 2000 psi or so when you hit the stop in the direction that puts pressure on the guage. Note: oil will shoot out of the open cylinder ports if it has not already drained out when you took the hoses off. Switch everything to the oter side to check the other cylinder by itself. You should now know where your problem is assuming nothing is bent and fluid can return to the tank because you can angle the blade by pushing on a tree.
Good luck.
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Without troubleshooting it I would guess either a broken cylinder rod or the nut came off that holds the piston to the rod. This can happen due to a severe shock load while the blade is partially angled.
Since the damage is internal when this happens, there is no telltale leak.
Since the damage is internal when this happens, there is no telltale leak.
Nige
Senior Member
When you try to move the angle cylinder does it appear as though the hoses are being pressurized..? You may need help to check this if the hoses are not visible from the cab. I guess there will be 2 hoses feeding the angle cylinder. Try moving the cylinder one way and observe what happens to the hoses. One of the 2 hoses should jump/vibrate/go more rigid as a sign that the control valve is sending pressure to the cylinder. If you try to move the cylinder in the opposite direction the other hose should exhibit the same symptoms. This would pretty much confirm that you have hydraulic pressure to the cylinder and whatever problem you have is inside the cylinder itself.
However if the hoses don't show signs of pressure in the test above my suspicion is that the problem does not lie in the cylinder.
However if the hoses don't show signs of pressure in the test above my suspicion is that the problem does not lie in the cylinder.
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old-iron-habit
Senior Member
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- Nov 22, 2012
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- Moose Lake, MN
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- Retired Cons't. Supt./Hospitals
If you have oil flow and suspect that the oil seal on the inner piston is leaking, an easy test is to have the cylinders partially retracted so the postons are in the middle of there travel. Then with the blade against a tree power the cylinder with the control for a minute or so. The cylinder will quickly warm up from the bypassing oil at the leaky piston position telling you what cylinder has the blown seals.