Just got an old PC400-5 with around 4000 hrs on it. First excavator purchase. Mostly going to be used on the ranch for putting in some new roads, laying some irrigation pipe and digging some ponds. Need some various parts like replacing a couple of the grease lines (they apparently broke and were bypassed with direct zerks but now very inconvenient to reach the zerks). Can I use some sort of generic grease tubes, or do I have to pay big dealer prices, or are there good sites to buy new/used/aftermarked Komatsu parts? Found one website online that looks to be about 25% cheaper than dealer, but dont know if they are reputable and not sure if its ok to post the name here to ask. Also need some other parts: 2 windows replaced (maybe an auto glass place would be cheaper than dealer... ) Not all the lights on the monitor are working (can this be repaired?) Inside door handle missing Safety lock lever broken off have new set of teeth, but vert pin tooth adapters are worn down to the point that I dont think we can even weld on the new teeth because there isnt enough shank left to fill the teeth enough to prevent the leverage from immediately breaking them off. Is it possible to weld up material onto the shanks, and if so what is the recommended approach? How difficult and costly is it to replace the shanks in comparison? Also, cant quite believe the manual says to wait 100 hrs between greasing the pins - seems way to long to me. Anybody know how I look up if this has the Komatsu or the Cummins engine? Any ideas for the best places to go for parts, and what to watch out for with this model would be much appreciated.
If you search kom pc400-5 injection pump you'll get some pictures of the pumps for different engines.. and just compare to yours..
A hydraulic shop should be able to make up your grease hoses, or you can order them online easy enough with the length and type of fitting at each end. The grease tubes I've taken off (for the same reason, they popped where they flexed) were a light plastic that you'd never guess was rated for 6,000 psi or something like that. A regular glass shop is the place to call for the windows, they know how to cut laminated safety glass and install it, and if they don't, call another glass shop. For the shanks, how handy are you with a torch and welder? It sounds like you need new shanks, but building them up and grinding to fit can work too. A bigger machine like that assumes a better grade of operator. Has better seals and keeps the joints higher out of the dirt. That's my guess as to why they get away with a hundred hours.
Komatsu uses jis metric tread fittings and hoses if you go to a hose shop tell them it's for a komatsu. Find someone local to make hoses and they can do grease lines. Greas machine every day after a few days you'll see how many pumps each pin needs over greasing just makes a mess. Fuel machine at end of day keeps condensation out of take. Drain bottom of fuel take few times a year. Change finAL drive oil and swing drive oil don't need to be changed often but it will worth your money starting with fresh. And change pump drive oil yearly also drain water from house bearing pan and add few fresh tubes of grease
Excellent points. If it hasn't been in regular use up till you bought it, then check the tank drain every day until there's no dirt or water coming out. Then in a week, then in a month, etc till you know how clean the tank is.
I've worked on a few of those machines and believe they are the best there was for that time frame. The grease hoses that have pipe fittings are British Standard Pipe or BSP. The secret to them is that they are nearly the same as an 1/8 inch NPT and what you will likely find is that the fittings installed now are just NPT. IF not you can start a NPT tap in the hole if it is too tight to get a standard fitting into. For the lines you can use standard old brake line you get from an auto parts store. Door handles you can fab something up or check out a salvage place for parts. The cabs on the Komatsu excavators of that time frame were all the same. The door from a PC120-5 will fit a PC400-5 and all the parts in the cab shell are the same. Auto glass works just fine for the cab and you might have to get some of the window gasket or beading. You can buy that stuff by the role from the glass people or from a catalog hours like Granger. The lock lever is just a piece of bar stock with a piece of tube on one end drilled for a role pin. You can make it or check out the wrecking yards again. The manual did say 100 hours between changes but they also liked to sell pins, bushings and seals as well. Basically grease a minimum of every eight hours except for the slewing ring bearing. Do that when you change engine oil and then only one or two pumps in each fitting and then rotate the house a couple of times. The only engine I've seen in a 400-5 is the S6D125 Komatsu engine. You can tell by counting the valve covers. The Komatsu engine has one head for each cylinder so six valve covers. If it has the Cummins engine it will be a M11 with the big fiber glass valve cover that always leaks. I have a video on YouTube showing maintenance on PC120 and PC150-5 machines that will show you most of what you need to know to keep the machine running. All the stuff is the same but will be in different places. Here is the link. https://youtu.be/papdAwY5wxo Good Luck
Thanks for all the replies! Teeth - I can do basic welding, my brother is certified. Just trying to figure out where to start or whats recommended. Just weld on lots of material? Add some sort of stock? What shape and grade stock? Thinking we weld on, then check how it fits the tooth, maybe hammer on the tooth a bit to make marks on the shank showing where needs more/less material and continue with welder and grinder... any pointers? Need to use torch to heat it up first? Changing the shanks looks like a pretty huge project and guessing they cost a pretty penny. Maybe making a simple cast of the inside of the tooth would help so we can see what shape we are aiming for with the welding on the shanks... Grease lines - so these lines have multiple bends. Not sure how to have a local shop replicate them since I dont have the originals, but you say maybe there are good flexible plastic versions? Or are you saying the plastic kind is bad? Ill start calling local shops - thanks for the info on jis metric tread fittings. Changed all the filters and the fluids - hydraulic, engine oil, final drive, damper, swing, final drives... what is pump drive oil? Replaced the antifreeze cartridge and topped it off, didnt do a flush. Thanks for the info on the fuel tank drain - Ill try draining the bottom of the fuel tank - sounds like just a bit out to get any debris, and do it regularly. Ive just got some 55 gal drums and rotary hand pump in the pickup to fuel it up, so not sure I can realistically top off the fuel every day. I guess I should keep a closer eye on the fuel/water separator. Ill call some glass shops. We are way out in the boonies, prob and hr away from any city with glass shops, not sure how to get the exact size/shape to the glass shop... maybe a cardboard stencil to bring in to them? rmllarue91 - "drain water from house bearing pan and add few fresh tubes of grease" - how do you do that? Speaking of grease, any old grease ok? Does it need to have some sort of designation? Anybody know anyplace cheaper than the dealer to get komatsu parts?
Sorry, I assumed you were talking about flexible grease lines. You can order copper/nickle brake line if you want to go that way, it's easy to bend by hand and flares easier than steel lines also. You really want to keep the tank full to keep water out. Except run the tank low occasionally to use up all the old fuel. Yes, just as much as needed to get the junk out, and as often as you have to until there's no junk. EP grease with moly is what you want for pins and bushings.
Thanks for the info and youtube link, that was helpful. So using standard brake line, I can just just regular steel brake line and flare fittings instead of the komatsu setup? I think the fittings are metric... And I assume I can just bend the brake line where I want it - is there a special way to do this to avoid kinking it, or just go for it? Dealer wanted over $150 per line... so this sounds a LOT better.
They make a little tool to bend the brake lines without collapsing them. Auto parts store you get the lines at should have a couple different versions of them. I'd bet the threads are like John C. said. Nothing you couldn't re-tap if needed. Who knows what's even left at either end of things. Junkyard
marie cottage EP grease with moly, OK. What should I be paying for that? Recommendations on the cheaper places to get that in the US? Something different for the track tensioners and swing, or you just saying get the higher end EP moly grease for the pins and bushings and use it on everything. Ok, Im off to get copper/nickle brake line tomorrow then, thats a big help. Hmm, Ill have to work on how to keep it fueld up at the end of each day. Just how bad would it be not to? Dont exactly have a dedicated service truck for it...
The problem with not keeping the fuel tank full is condensation of moisture inside the tank, which will cause the exposed steel inside the tank to rust, which will add more dregs to the bottom of the tank over time. Also, this condensation eventually goes to the bottom of the tank creating a layer of water between the bottom of the tank and the diesel fuel in the tank. Again, that will cause rapid rusting of the bottom of the tank, that's the reason every one is recommending keeping the tank full, controlling water in the tank. Like John C stated, all the fittings on that machine are metric JIS "Komatsu" style fittings, and all the pipe thread joints would be either British Standard Pipe Taper or British Standard Pipe Parallel.
Ok, I got extra fluids, extra keys and 5% moly ep grease around $2/tube from the dealer and from a local wholesale fuel and oil supplier. Tomorrow we have a high of 20 degrees and then -8 overnight, so Ill get to the brake lines for the grease in a couple days when it warms up. Ill let you know how it goes. Looking to pick up a couple more 55gal drums for fueling to try to keep it fueled up.
I would weld new shanks on. Worn shanks won't hold teeth and I'm not sure they would be worth building up. They may still drop teeth after you spend hours and hours working on them. Aftermarket shanks are cheap, mine cost less than the teeth. Welding them on isn't too big a deal, certainly not worse than building up and grinding old shanks. The bugger is getting the old ones off. I've cut lots of them off with a torch, but an air-arc is the best tool.
Where did you go for aftermarket shanks? We have a torch and plasma cutter to work on the old ones...
Several places I spoke with said that they dont sell individual parts like a door handle assemby, only the entire cab. Anyone have recommendations for used parts places I could contact that would sell individual parts or components?
I got the shanks at HeavyQuip. A torch is less than ideal, but very doable. I would go easy on the plasma cutter getting the old ones off. They are pretty indiscriminate about what they cut. You may cut the heck out of the frog.
Ok, thanks. Ill check out HeavyQuip. Sorry for my ignorance, whats the frog? So, you mean careful to only cut between the shanks and the front edge of the bucket, and attempt not to cut into the front edge of the bucket? Front edge of the bucket between the teeth is pretty worn, large curves worn back between each shank. Should we be welding on some sort of hardened steel to repair or replace the front edge of the bucket before welding on the new shanks? Ill try to post pics soon...
Yes it's the front lip of the bucket. It is solid. The shanks are split and weld to each side.
We ended up cutting off all the teeth adapters with a torch and welding new ones on. They are the ESCO twist lock style. LOTS of welding rod. Will post pics. Still need to replace some grease lines, a couple were broken and we just put in zerks at the end of the broken lines, but its a pain crawling up onto the end of the boom to grease. Anyone replaced komatsu grease lines? Apparently the flare fittings at the end are a special british standard pipe thread and the lines themselves dont appear to be the same diameter as automotive brake line. Any tips?
Regarding your fueling situation is it possible to get a empty 1000lt shuttle (cube) and use that? You could possibly place it on a high mound of dirt so it will just gravity fill the digger.