going to be rebuilding the center joint in my hitachi ex230lc-5 have a couple questions. when removing the unit from the machine is there any tricks to not get an oil bath when removing the hoses from underneath? I'm going to be draining and cleaning out the hydraulic tank as well because im getting 3 cylinders rebuilt and am starting over fresh. when i take the top hoses off of the center joint will they continue to puke oil out unless they are capped? Been wanting to do this for while but it wont stop raining, and when it does i have to go seeding so hopefully next time it dries up i can make it quick.
I will be doing this with a 120 in the next couple of weeks. I would suggest getting a bunch of caps and plugs, and do them on top of the swivel first, then go down and repeat. I cap everything I don't want to add any dirt to the system.
Everyone I've done I just pulled the center out in the machine and left the outer part bolted in the track frame may not always be possible tho
Put a vacuum on the hydraulic tank to minimize the amount of oil ending on the ground. I put a drain pan under the machine to catch what I do lose. When you take the upper hoses loose tie them up above the level of the tank and tie off some rags over the open ends if you don't have caps and plugs. The lower hoses are best capped and plugged and you will lose a bit of oil. You are going to get dirty and have oil down your sleeves. I have stuffed rags inside my sleeves and tied them off with some cord or zip ties especially on small machines where there is no room to work.
I like the vac on the tank idea. Thanks John.
The last Hitachi swivel the I did, I had to drop the entire swivel out the bottom of the machine.
that is what I figure on doing. I'd hate to damage the lines by leaving it in dangling somehow.
Good day Attached a couple of bits of information that maybe of help.Be aware that the main valves are open to tank, (vent the tank before you begin) meaning fluid will run from all those connections. Be sure to prepare with suitable plugs before you begin (Many hose suppliers have plastic plugs ideal for the purpose), disconnect the top first and drain the lower connections to a catch. That will minimize the mess. Kind regards Uffex
Thank you for that, uffex. This will all come in handy, the vacuum trick John had and these PDF's. I will buy all the hard caps and plugs I need. We have an account at a place about 20 minutes away and I can get a count going and just stock up. Having done it the hard way I prefer the right way. I also pre-cleaned the top swivel/main valve bay and pre-loosened all the lines and bolts while it was easy.
Thank you Uffex, I was trying to find that information on the centre joint. I also figured that the lines would drain. I am going to drain the tank completely and clean the tank out prior to removing the centre joint. Try and empty as much oil out of the system as I can. The oil is very poor. Dirty, and is quite a weird mixture of random oils by the looks of it. I took all the belly pans off my machine and I didn’t see a valve or plug to drain the hydraulic tank from. Just the main suction line on the bottom, and that would make quite the mess taking it off.
there is a plug on our 120 located on that same lower plate. Look again and one of those bolts might be a drain instead.
so the only thing I seen that looked like it might be a drain plug on that elbow is a small Allen key plug. About the size of your pinkie maybe smaller. Is that what you were talking about? Will take a while to drain out that thing lol but I got the machine orientated to drain the tank and try prevent as much oil spill as I can. Also taking the bucket and two boom cylinders off to rebuild them.
Yes that allen plug in the elbow is what I used
It was finally calm enough to try and drain the hydraulic fluid. Been around 50mph winds for the last few days. Today it was only 20mph but i still managed to make a mess from the wind blowing the oil when it gusted. I drained the tank empty, removed the return filter, removed the pilot filter, cleaned out both housings where the filters go. There was some nasty sludge at the bottom of the return filter. Then removed the whole elbow at the bottom of the tank drained everything out of it and the pump. cleaned the bottom of the hydraulic tank out. But the intake screen is not really a screen anymore. It only has the tube frame with the holes on it, all of the screen material is gone off of it and it wasn't in the tank. So i gotta buy a new intake screen now. Would it be a bad thing to crack the oil lines at the drive motors to drain the oil from the centre joint? That way i dont spill any oil all over myself? Also, the pilot filter was collapsed. Only things that i could think that would cause this is the relief being plugged, or the filter being completely plugged up...
I'm going to use the bucket and boom to lift the front half off the carbody. Are you going to hoist the whole thing somehow? You could cap off the lines coming out of the main valve and drop the swivel, and then re-fill the tank and fix all the other problems so you can get an assist from it.
Good day I would suggest that if you are new to the machine that a previous owner removed that suction screen, if the pumps swallowed that without serious damage would be unlikely. Be sure to bleed the pumps before you commission the machine. Attached is a tank illustration I'm not sure if it is the same for your side of the water. Kind regards Uffex
I did some reading and seems like you are correct uffex, it must have been removed by the previous owner. It makes sense not to have a need for such a fine mesh filter post the return filter. There should not be any kind of contaminates getting into the tank after the filter. Only during servicing. So I’m not going to replace the pre filter. It still has the steel frame of it with all the holes. That will be enough in my opinion. I will go through the pre screen and try and clean up and pieces I see of the mesh that might come off. I do not want anything going through the pump. I’m going to be dropping the entire rotary valve out the bottom, I believe it weighs 70 pounds so it’s not too heavy. But at the same time the valve itself will probably easily pull out and then I can suck the oil out of the valve body. I’m just trying to not make a huge mess of oil. I hate dropping oil on the ground especially where I have to work.
I welded a hook to one of the caps and lowered it with a come a long from another machine.
Case drains from the swing and travel motors do not return through the filter. The dump directly back into the tank. The screen is all there because of people putting contaminated oil in the tank from re-used 5 gallon buckets.
Finally got around to doing the centre joint. Bought the seals before taking it apart tried to be ready so it didn’t have the hydraulic system open to contaminates. hydraulic tank pre drained, started by loosening the hoses from underneath and with a drain pan I let the lines drain whatever fluid could come out. Everything is nasty oily underneath even after pressure washing. Didn’t understand how one could get the centre joint out without splitting it so pulled the inside out. Then went underneath and dropped the housing. Boy that was awkward balancing that greasy oily thing one handed. Must’ve been original seals everything was completely flat. And hard as a rock. Removed the seals and then put all the new seals in. And sure enough got one wrong seal. The very top dust seal. The very last one I was going to install. Dealer didn’t have any of the right ones either. So had to order it for first thing today. Took the rubber grommet off the frame cleaned it up too. Then put the grommet back on. The lower case. Took some effort to push the centre section back in. But it’s so much tighter then it was before. the job was not hard or complicated. Just dirty, and awkward positioning. Would’ve been a heck of a lot easier if I was a foot shorter and had smaller hands. Took my two boom cylinders and the bucket cylinder in to get rebuilt. Then when I get those back on and together I can refill the hydraulic system. Does anyone have the procedure for bleeding the pump and hydraulic system? There isn’t much oil left in the machine. Maybe the stick cylinder and the drive motors. That’s about it.
Although the screen is expensive it's cheaper than a pump. When the oil is cold it will bypass the return filter. When the filter is full the oil will bypass. I usually replace the screen when I replace a pump. Bob
Good day Method to bleed & prime dry components, fill the tank leave the delivery & drain line of the pumps- crank the engine with the stop control at stop until fluid is evident, after a short period fluid should also flow from the drain line. Motors leave the drain line open until you see fluid. Initial starting run a low revolutions for 15>20 minutes no pressure, that should flush any unwanted back to the filters. Cylinders fully stroke the bucket & arm 3 or 4 times to avoid bottoming those out. Boom you can only raise & lower from ground level again 3>4 occasions.. Attached a little late I guess. Kind regards Uffex
I won't start an engine on any piston pump until I have oil coming out the case drain. I'll even put some low air pressure in the tank with the case drain hoses removed until I get oil through those fittings. When I do start the engine, it is at low idle and then I'll crack threaded fittings on the pump until I get fluid through them. You don't have to bleed motors because they won't move unless there is oil going through them. For cylinders, I'll leave the hydraulic tank cab loose or sometime off while going through the bleed process. I'll move the cylinder maybe six inches each way and gradually increase the stroke until I'm certain the cylinder is full. I'll also keep checking the hydraulic level as it will go down rapidly while filling the cylinder. I'll keep putting oil in the tank as the cylinders fill. Once the cylinders are full, I'll put the cap back on the tank and cycle all the cylinders to build pressure in the hydraulic tank.
I bought a new suction strainer to throw on before I fill up the hydraulics. Just waiting for my cylinders to come back
Got back from a vacation. Got my cylinders back from rebuild. Got the bucket cylinder ready to go on the machine. But the boom cylinders are not hooked up to the boom yet. I left them off the boom so I can cycle them without any pressure. And plus extend them out to the proper length to put back on the boom. Just need to fill up the hydraulic tank and bleed the pump now before I can do that
Haven't gotten around to working on my machine since my last post, my back is toast and couldn't even lift a wrench. I added oil in the tank, but these wasn't an obvious hose on the top of the pump to bleed the air from. There is two large hex bolts with a threaded hole in each though. I'm assuming those are the two places to bleed the pump from as they're at the highest location? There is also two hoses that come down off the outputs, that go to a literal piece of iron and are threaded on. It does not go anywhere. Do I also crack those lines and let them bleed or what are those hoses for? Also, what measurement for deflection on the tracks when setting track tension? I need to loosen the tracks some, they're way too tight right now.
I'm with you there. It really sucks having a sore back!