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Hydraulic oil drain- now pilot controls won't work??
- Thread starter jav
- Start date
Well good news finally! The machine is fixed and I did it myself because the Pro just couldn't make time for me.
First- Yup- I screwed up marking the hoses AND the Komatsu manual is wrong in the same way that I marked the hoses wrong. I now know what I did but it wasn't apparent AND it wasn't the only problem... just 1 of 3.
The second problem was an aluminum block that houses the stop, 2 speed and servo enable solenoids , rotted away on the bottom. What I thought were broken screws and solenoid leaks were not. The entire lower aluminum block literally disintegrated away and was very likely the source of all my leaks. I had to machine the block and weld in a new section to fix the leaks and drill and tap new fastening holes to properly secure the solenoids .
Lastly- the brake solenoid connector, which is a europulg style, had a broken wire inside the rubber waterproof shield. depending on how you held the connector, it would or would not make contact... which explains why the coil was heating up , showed voltage when probed but didn't always work when plugged onto the solnoid.
Because the brakes were intermittently not releasing, it caused me to believe my hose b/d swap test made things worse when in actuality, it should have shown that it fixed my pivot issue but -was pivoting in the wrong direction... the problem was actually a hose a/c swap- which is on the right side of the machine. The reason i marked those wrong is because I had removed hoses b & d one at a time and marked each one as i took it off. On the right side of the machine -that wasn't possible because there were 4 other hoses in the way that had to be removed before i could get hoses a/c off. In roving those hoses I had a mess going with oil everywhere and I'm pretty sure i removed both a & c hoses, put them down and then reconnected the other 4 hoses to minimize oil loss. I changed gloves to put on the labels so they wouldn't get oily and fall off. I must have screwed up sticking the labels on after both hoses were removed and on the floor The fact that the Komatsu manuals showed the exact same error as my marking error made me trust my mistake even more.
In the end- at least on my machine- each pump needs to feed 1 motor and there should NOT be a cross over as shown in the manual . I'm glad this is over and I learned a lot! Thanks to all who chimed in and helped and put up with my frustrations... I really appreciate the education.
First- Yup- I screwed up marking the hoses AND the Komatsu manual is wrong in the same way that I marked the hoses wrong. I now know what I did but it wasn't apparent AND it wasn't the only problem... just 1 of 3.
The second problem was an aluminum block that houses the stop, 2 speed and servo enable solenoids , rotted away on the bottom. What I thought were broken screws and solenoid leaks were not. The entire lower aluminum block literally disintegrated away and was very likely the source of all my leaks. I had to machine the block and weld in a new section to fix the leaks and drill and tap new fastening holes to properly secure the solenoids .
Lastly- the brake solenoid connector, which is a europulg style, had a broken wire inside the rubber waterproof shield. depending on how you held the connector, it would or would not make contact... which explains why the coil was heating up , showed voltage when probed but didn't always work when plugged onto the solnoid.
Because the brakes were intermittently not releasing, it caused me to believe my hose b/d swap test made things worse when in actuality, it should have shown that it fixed my pivot issue but -was pivoting in the wrong direction... the problem was actually a hose a/c swap- which is on the right side of the machine. The reason i marked those wrong is because I had removed hoses b & d one at a time and marked each one as i took it off. On the right side of the machine -that wasn't possible because there were 4 other hoses in the way that had to be removed before i could get hoses a/c off. In roving those hoses I had a mess going with oil everywhere and I'm pretty sure i removed both a & c hoses, put them down and then reconnected the other 4 hoses to minimize oil loss. I changed gloves to put on the labels so they wouldn't get oily and fall off. I must have screwed up sticking the labels on after both hoses were removed and on the floor The fact that the Komatsu manuals showed the exact same error as my marking error made me trust my mistake even more.
In the end- at least on my machine- each pump needs to feed 1 motor and there should NOT be a cross over as shown in the manual . I'm glad this is over and I learned a lot! Thanks to all who chimed in and helped and put up with my frustrations... I really appreciate the education.
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Solid aluminum... and the machine is a 2010. My best guess, the machine was used near the ocean and for snow removal. My guess is salt got into the dirt and debris that was caked in the belly of the machine. The bottom of that block was sitting in that brine and just corroded. Heres a couple of pics
I'm just glad to have fixed it... this thing was kicking my butt!! Also- that block is no longer available from Komatsu. Luckily I have a machine shop in my garage and can weld aluminum. I checked this morning and so far- no leaks and everything works up on blocks. I'll lower the machine tonite, re-install the floor and see how she runs on the ground.
Welder Dave
Senior Member
Did Komatsu change the material or something that it's no longer available? I wonder if being wet like that somehow contributed to extreme galvanic corrosion between different metals. If they use lots of salt in the winter would certainly accelerate it. I know on aluminum body F150, you have to insulate the body from contact with steel even for simple things like installing mud flaps.
Put the machine on the ground last night. Works like a champ... even better than before since it seems the hydraulic system makes less noise? Perhaps the leaks were allowing air in? Sounds really good now. Also- got up this morning, and everything is dry. All is right in the world.