L555 deluxe hydraulics

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jawollbrink

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Joined
Nov 10, 2010
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Hi guys, new to the forum.. I recently bought a cheap L555 deluxe that had been parked for a couple of years. Supposed to have run fine when they parked it. I ended up rebuilding the injection pump on the v1902 kubota and got the engine to run like a top, then I had to add 7 gallon hydro fluid and it drive around good, but my boom isn't working right. The bucket tilt cylinder moved out about 8 inches but wont go in, and the boom goes in a couple inches(can't go anymore cause I have it pinned up in the air) but wont go up. I can hear the pump struggling when I operate it and all of them move about an inch but thats it. Also when I divert to the auxilery I have pressure. I cleaned the suction screen which was a little dirty.... ? What do I look for? I'm not an expert on hydraulics but I have to get this fixed so any ideas are appreciated. Also anyone have pictures on schematics? I can't find much on these machines online, I already bought a 75 dollar manual for the motor and dont want to buy another for the machine.
 

Tazza

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Dec 7, 2004
Messages
16,829
Sounds like a safety device. Check your seat, seat bar and seatbelt switches. If they don't detect you are in the seat, they will lock the hydraulics out. The system stops all fluid flowing to the lift and tilt by essentially blocking its path, thats why you hear the engine bog down.
 

irvi00

Well-known member
Joined
May 30, 2010
Messages
76
All right, I have a standard L555 with a perkins engine, and I assume the hydraulics are the same as your machine. First, the safety switch is under the seat, it's just a simple pressure switch that recognizes weight in the seat. Check it out, but I don't think thats your problem. Second, change out the hydraulic filters in the engine compartment, one big one and one small one mounted up on the firewall. Third, you have already checked and cleaned the suction strainer. Fourth culprit will be the control valve, located behind the shroud at your left foot. A rebuild is cheap, removing and replacing the valve is a booger. Finally will be the gear pump. From the engine there are three pumps in a series, first two are the drive pumps, on the front is a small gear pump bout the size of your fist. This pump delivers fluid for the boom and tilt. The only cure for it is replacement. You say you can hear the pump "struggling", that is probably starving for fluid, which means clogged filters or low pressure delivered from control valve. Mine once had the problem you describe, it was the relief valve in the control valve body. If you have to remove the valve might as well rebuild the whole thing anyway, not a hard job and a kit is cheap. I understand your concern with cost of a manual, but a service manual is GOLD.
 
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jawollbrink

Member
Joined
Nov 10, 2010
Messages
8
All right, I have a standard L555 with a perkins engine, and I assume the hydraulics are the same as your machine. First, the safety switch is under the seat, it's just a simple pressure switch that recognizes weight in the seat. Check it out, but I don't think thats your problem. Second, change out the hydraulic filters in the engine compartment, one big one and one small one mounted up on the firewall. Third, you have already checked and cleaned the suction strainer. Fourth culprit will be the control valve, located behind the shroud at your left foot. A rebuild is cheap, removing and replacing the valve is a booger. Finally will be the gear pump. From the engine there are three pumps in a series, first two are the drive pumps, on the front is a small gear pump bout the size of your fist. This pump delivers fluid for the boom and tilt. The only cure for it is replacement. You say you can hear the pump "struggling", that is probably starving for fluid, which means clogged filters or low pressure delivered from control valve. Mine once had the problem you describe, it was the relief valve in the control valve body. If you have to remove the valve might as well rebuild the whole thing anyway, not a hard job and a kit is cheap. I understand your concern with cost of a manual, but a service manual is GOLD.
I don't think its the seatbelt switch because the light goes out when I sit/ comes on when I stand. Also If I switch to aux hydraulics i have pressure (I know this because I have a small leak in the aux line that shoots fluid out if I switch it over). The cylinders do move some, it just sounds to me at least like the pump is working, just that something is blocked/ plugged. I am leaning toward the control valve, but I think I will try changing the fliters first. Does the valve have to be removed from belong by taking the bottom plate out? Also where can I get this cheap rebuild kit? I'm all about cheap, and rebuilding! Thanks for the help!
 

irvi00

Well-known member
Joined
May 30, 2010
Messages
76
I don't think its the seatbelt switch because the light goes out when I sit/ comes on when I stand. Also If I switch to aux hydraulics i have pressure (I know this because I have a small leak in the aux line that shoots fluid out if I switch it over). The cylinders do move some, it just sounds to me at least like the pump is working, just that something is blocked/ plugged. I am leaning toward the control valve, but I think I will try changing the fliters first. Does the valve have to be removed from belong by taking the bottom plate out? Also where can I get this cheap rebuild kit? I'm all about cheap, and rebuilding! Thanks for the help!
Try those filters first, easy and relatively cheap. If you determine it to be the control valve, good luck! It is a booger of a job. Had mine off three times. You will have to pull the skid pans off and remove the fuel tank. It's easier if you can get the machine elevated like on a grease rack. Then you gotta get all those hoses off, I suggest marking each hose to its place on the vavle to help replacement. If I remember correctly, some of these hoses will require a crowfoot wrench and some foul language. The rebuild kit should be available from any New Holland dealer. I suggest calling Messicks, (www.messicks.com), these guys know their stuff on these machines. There were two types of valves used on these machines, victor and cessna. You will have to determine which valve you have in order to get the right kit. As far as rebuilding the valve, I took my valve and kit to a local hydraulic shop and they did it for me. But it does not look like a hard job. It's just some o-rings and a few gaskets. Because it's such a job to get out, I suggest you make near 100 percent sure it's the valve body causing your problem. Hope this helps!
 
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jawollbrink

Member
Joined
Nov 10, 2010
Messages
8
Try those filters first, easy and relatively cheap. If you determine it to be the control valve, good luck! It is a booger of a job. Had mine off three times. You will have to pull the skid pans off and remove the fuel tank. It's easier if you can get the machine elevated like on a grease rack. Then you gotta get all those hoses off, I suggest marking each hose to its place on the vavle to help replacement. If I remember correctly, some of these hoses will require a crowfoot wrench and some foul language. The rebuild kit should be available from any New Holland dealer. I suggest calling Messicks, (www.messicks.com), these guys know their stuff on these machines. There were two types of valves used on these machines, victor and cessna. You will have to determine which valve you have in order to get the right kit. As far as rebuilding the valve, I took my valve and kit to a local hydraulic shop and they did it for me. But it does not look like a hard job. It's just some o-rings and a few gaskets. Because it's such a job to get out, I suggest you make near 100 percent sure it's the valve body causing your problem. Hope this helps!
alright, thanks for the advice. I am gonna try changing the filters and cleaning the suction again. If that doesn't work then I will rebuild the control valve. Thanks again, jason
 
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jawollbrink

Member
Joined
Nov 10, 2010
Messages
8
alright, thanks for the advice. I am gonna try changing the filters and cleaning the suction again. If that doesn't work then I will rebuild the control valve. Thanks again, jason
just an update, it had nothing to do with the hydraulic control valve, luckily I hadn't tore into it yet... I found it was a problem with the seatbelt logic board. The seat switch was working fine, 12 volts coming out of it when contact was made, but the two solenoids that control the boom and bucket where only getting 2 volts and not opening.. My solution: run a fused wire from battery into one side of seat switch, and back out to solenoids. No it runs just fine as long as you sit on the seat. Thanks for the help.
 

irvi00

Well-known member
Joined
May 30, 2010
Messages
76
just an update, it had nothing to do with the hydraulic control valve, luckily I hadn't tore into it yet... I found it was a problem with the seatbelt logic board. The seat switch was working fine, 12 volts coming out of it when contact was made, but the two solenoids that control the boom and bucket where only getting 2 volts and not opening.. My solution: run a fused wire from battery into one side of seat switch, and back out to solenoids. No it runs just fine as long as you sit on the seat. Thanks for the help.
Good news! Glad to hear you resolved your problem that easy. Even on these older machines a little electrical gremlin can still shut you down. Why on earth the manufacturers continue to pile the electonics into them is beyond me. Luckily my LS170 has not had any problems yet, I dread the day it does. I'm glad you hadn't gotten into that valve, trust me, you don't want to go down that road until absolutely necessary. By looking at past threads on this site, it seems that a lot of problems are caused by the safety stuff. I know that these things protect us, but the manufactures need to beef up and make this stuff "bullet proof". It's tough when a simple little safety switch shuts down a job for several days.
 
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