My 555 boom pedal is seized up. The spacer on the hydraulic pump split and have bought replacement. The boom pedal seems to be seized inside the control valve. The rest of the hydraulic controls are moving freely. Any ideas/suggestions what it could be and remedies?
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Does yours have the electrical lockout solenoids on the control valve? If so check for power at all of them , if they all have power remove the boom one and put a plug in the hole temporarily. I would guess you can bench test it with 12v power to see if it moves or is stuck. If not the solenoid and it gets power I have no idea. With the solenoid out the valve should move but don't run it that way because of the safety issue of people lifting the boom , stepping out of the cab and accidently hitting the pedal. Bad things would happpen very quick.
Prior to this the boom pedal would operate in reverse manner.Does yours have the electrical lockout solenoids on the control valve? If so check for power at all of them , if they all have power remove the boom one and put a plug in the hole temporarily. I would guess you can bench test it with 12v power to see if it moves or is stuck. If not the solenoid and it gets power I have no idea. With the solenoid out the valve should move but don't run it that way because of the safety issue of people lifting the boom , stepping out of the cab and accidently hitting the pedal. Bad things would happpen very quick.
Almost sounds like a linkage problem and maybe the detent for the float position went haywire. If the valve is down between your feet take the cover off and have a look. On mine the linkage at that point is set up in kind of a flimsy arrangement in my opinion anyhow. Does the boom pedal seem to be locked in neutral?Prior to this the boom pedal would operate in reverse manner.
The machine hasn't been used for 3 yrs. I checked the linkages and they appear fine, whatever it is seems to be inside the control valve. I don't think it could be the safety solenoids because there is no hydraulic pump on it and system is dry. My next step is to take the control valve off and see what it looks like on the inside. Was hoping it wouldn't resort to this. Prior to this I had checked for restrictions in cooler, replaced filters and fluid. After that I tried out controls and spacer in pump split when I tried to lift bucket, I drained system. Was injured at work and am just now able to get to work on it again.Almost sounds like a linkage problem and maybe the detent for the float position went haywire. If the valve is down between your feet take the cover off and have a look. On mine the linkage at that point is set up in kind of a flimsy arrangement in my opinion anyhow. Does the boom pedal seem to be locked in neutral?
I'm hoping that someone may know if this is a possibility. I had read in another thread that the L555s can become air locked from losing fluid and not bleeding air out of strainer cap when refilling. I lost the boom cylinder seals and had them replaced, replaced my filters and changed fluid prior to the pump splitting and the controls acting up. Could this possibly been my problem? A massive air lock?The machine hasn't been used for 3 yrs. I checked the linkages and they appear fine, whatever it is seems to be inside the control valve. I don't think it could be the safety solenoids because there is no hydraulic pump on it and system is dry. My next step is to take the control valve off and see what it looks like on the inside. Was hoping it wouldn't resort to this. Prior to this I had checked for restrictions in cooler, replaced filters and fluid. After that I tried out controls and spacer in pump split when I tried to lift bucket, I drained system. Was injured at work and am just now able to get to work on it again.
No. If I understand your post correctly, the center section of the hydraulic pump split. Generally when a pump splits it is because the relief valve is not functioning properly. It is possible a piece of metal migrated to the control valve and is wedged in the lift spool. The only way to know for sure is to remove the valve and disassemble it You could probably remove the spool without removing the control valve, but you still will need to remove the fuel tank. If the unit had been sitting awhile I would suggest spraying the exposed spool with penetrating oil and lightly tapping it into the valve body. The spools have a tendency to stick on the oring seal after setting a long time. Since yours was working I don't think I would try that.I'm hoping that someone may know if this is a possibility. I had read in another thread that the L555s can become air locked from losing fluid and not bleeding air out of strainer cap when refilling. I lost the boom cylinder seals and had them replaced, replaced my filters and changed fluid prior to the pump splitting and the controls acting up. Could this possibly been my problem? A massive air lock?
Thanks for the reply, I was hoping not to have to remove control valve but it looks inevitable. Will report back with what i find.No. If I understand your post correctly, the center section of the hydraulic pump split. Generally when a pump splits it is because the relief valve is not functioning properly. It is possible a piece of metal migrated to the control valve and is wedged in the lift spool. The only way to know for sure is to remove the valve and disassemble it You could probably remove the spool without removing the control valve, but you still will need to remove the fuel tank. If the unit had been sitting awhile I would suggest spraying the exposed spool with penetrating oil and lightly tapping it into the valve body. The spools have a tendency to stick on the oring seal after setting a long time. Since yours was working I don't think I would try that.
I was finally able to get the machine moved from the field to my shop, was really lucky that the wheels rolled so made things a lot easier. What I have found to this point is when I open the aux. valve, the boom or the bucket tilt, all that comes out is water, no hydraulic fluid. I opened up the chain case and there wasn't any water just fluid, fluid was clear. The water came out the line that goes to the hydraulic pump which I had off because of gear housing cracking.Thanks for the reply, I was hoping not to have to remove control valve but it looks inevitable. Will report back with what i find.
