Hello to all! I noticed a problem about a week ago that is getting worse over time. After the machine warms up for about 3 to 5 minutes everything sounds normal. When you first start to move forward or backwards the machine sounds and moves great for about 4 to 5 feet then slows down to about half its normal speed and creeps along, it sounds like the pump is struggling to move the machine at all. If I then stop moving ,the pump seems to catch up and everything sounds normal again. The machine doesn't react well when multitasking, ie boom up and stick out or swing and boom up or anything. It give the same noise and sometimes will almost come to a complete stop. Traveling up hills produces the same effect, it will move, but very very slow. I want to say it could be the hydraulic oil and filter needs to be replaced or the screen in the bottom of the hydraulic tank could be clogged. I don't know if it could be the fuel filters. I hope its not the pump going bad, I thought the pump either works or it doesn't work, no in between. Looks like I'm going to have to spend some money to troubleshoot the problem. Thanks in advance for any advice. ointhead
grubber... Does it sound as though the engine is under load or off load when the problem occurs?
Yeah. It sounds like that. Its hard to say though because komatsu machines make a whinning noise normally anyway.
How many hours? How many hours since last MAJOR service? (I.E. major service including 1000 hr hydraulic fluid flush) I have no Idea if this relates, however, we have a brand new T250 Bobcat that experienced the same problem. Worked super until it reached operating temp, then puked out. We found two pinched fuel lines, a worn through hydraulic hose and a severely plugged fuel and hydraulic filter. Mind you that this machine has 700 hrs on it
service I purchased the machine from a dealer and they did the inspection and service before I purchase it. Had 3446 hours when I bought it and it has 3900 now. I don't know if they changed the hyd. filter or if they flushed. I guess I need to change the fluid and filter and see if that works.
We got the same problem with one of our 210-7 that had been parked for 6 months before we got it back from Afghanistan. The mekanics changed the fuel filter and all that before we got it back, but it worked for 2 days. Then it just lost power, multitasking was impossible, the engine "worked" as hell, but no black smoke. If u got black smoke it gets enough fuel, then u can look for problems with the hydraulics. If u got no smoke from the engine, it dosen't get enough fuel. I bet its diesel animals blokking your filter or fuel-lines. There is additives to put into the fuel to kill the animals.
The usual problem is not enough fuel supply. When the engine does not get enough fuel the computer senses the drop in RPM and destrokes the pump. The result is the machine slows down but you don't hear the engine slowing down. The fuel transfer pump has a strainer in the banjo bolt that connects that tank hose to the pump. The bolt is on the bottom of the pump and if your machine has air conditioning it is very difficult to get at and get out. Once you get the bolt out look at the end of it and you should see the white plastic with a screw driver slot in it. Unscrew the strainer from the bolt and blow it and the hollow in the bolt out with air pressure. There are two seals for the fitting and most people loose the one that goes next to the pump. You can get copper fuel line washers from the local auto parts supplier to work if you loose the originals. If your machine does not have the hand transfer pump, then you have the inline strainer that looks just like an automotive filter. Those can be blown out with air pressure and put back in. The original strainer has a brass basket on the inside instead of paper. They can only be sourced through a dealer. Do not install an inline filter from a parts house. Automotive filters are made from cellulose and swell up when water hits them choking off the fuel supply. You did not indicate that the monitor panel showed any fault codes of alarms so I would not think there are any electronic problems. Good Luck!
Engine speed? It sounds like what? Engine under load (engine speed drops, lugs down maybe close to stalling) or off-load (engine speed or sound doesn't change much). Also does it make any abnormal smoke? Try putting the stick over relief and watching the engine speed on the monitor, it shouldn't drop below rated speed. Compare the speed attained with HFI.
engines under load. Thanks for all the responses so far. What is a banjo bolt? I looked on the parts book and I didn't see anything that referenced banjo. is there another word for it?
Welcome to HEF grubber! :drinkup
Banjo bolt and fitting. There is a small plastic strainer that fits into the end of the bolt, they can become blocked easily if you have crud in your fuel tank. Had a 120 hitachi that i had to clean the strainer out every week or so, because of the same problems you describe. Boss told me to just toss the strainer cause i was wasting time having to clean it out so often ointhead
As most have said... the most common cause of lack of performance is the fuel system and you should ensure that there are no restrictions in the tank, suction lines and from the feed pump. Also make sure that you have the right fuel cap to ensure the tank is vented. On the hydraulic side it is best to follow Komatsu maintenance intervals for oil and tank filter replacement and use of the correct oil is very important. If your hyd pumps have the high pressure strainers on the pump outlets (they look like small cylinders) don't overlook these. It has been known for these to become restricted - they may look OK visually but the extra fine mesh can become blocked almost like glazing, maybe from some oil additive or chemical reaction. This will restrict the pump output upsetting the operation of the load sensing system. You can run the machine for testing with them out just to eliminate them from the equation.
The Problem has been neutralized Thanks to everyone that posted. I resolved the problem this morning at about 7 oclock. I got on the machine and it would not respond to any joystick movements. I had a couple of fuel filters on hand, so I started there. Low and behold it was the dam fuel filters. I couldn't believe it, I've never seen filters cause so much of a problem. Thanks to all the post, I didn't know it was a fuel starvation problem. I guess the dealer didn't change the filters before they sold it to me, although they said they did. Have a good one everybody.
Hi Grubber, it's great to hear you got it going. I just need to remind you that the fuel filters are down stream of the strainer I spoke of in the earlier post. If the fuel filters are plugged then so is that strainer. You will probably see it on a long travel up a hill. Good Luck!
Thanks I think your spot on bud. I did notice a slowdown this afternoon traversing a a big hill. I didn't check the strainer yesterday. I'll take a look in the morning. Thanks for all the help. Would you know where the strainer is in relation to the fuel filters? Would it be on the same side of the engine as the filters?
I dont know about komatsu, but I usually see then right on a banjo fitting that feeds into the fuel filter.
If your Komatsu has a hand priming pump underneath the fuel injection pump, the banjo bolt is on there. You will see a hose going to the bottom of the pump and the banjo bolt connects that hose to the pump. If you don't have the hand pump then there is an inline filter back by the rear motor mount on the same side as the fuel injection pump. Good Luck!
Checked it I checked the banjo bolt on the side of the pump. It wasn't that hard to get to and I do have air conditioning on the machine. I didn't see a a strainer when I took the bolt out. The bolt wasn't clogged with anything. Any more ideas?
Hi Grubber, The bolt on the side of the pump is the discharge to the filter. The one you want is on the bottom of the pump. Good Luck!
Banjo Blues Have seen that banjo screen clog up problem numerous times and have people really scrathing the heads , it's on the supply hose coming into the hand /lift pump , usually on the bottom with the hex head facing up , it's used by alot of manufactuers and a very easy fix that is often over looked , as stated if your filters were bad that screen is most probally too , and changing filters seem to make the problem go away for a while but will return if not cleaned out , also have seen clogs in the supply fitting off the bottom of the tank -----another thing to mention is when you have really dirty filters it is a good idea to drain off the bottom of the tank after the machine has set still for a long period of time , like over night , as new filters are quickly clogged up from trash in your tank
Banjo bolt with strainer question. John C you wrote in 07 that the Komatsu engine on an excavator had a strainer in the "lower" inlet side of the lift pump. I have been having the same fuel starving, stalling issues with my little D20. When I took the big hex cap on the side of the lift pump off I got a glob of grit out along with the spring. Also the handpump seemed not to be getting very much supply even though the fuel was free flowing from the main fuel line. If there is a strainer which clogs regularly, has anyone done one better and put in an inline sediment bowl and got rid of there strainer? The problem there is space and accessability. Is there a rebuild kit available for the lift pump and hand primer? Old
In line automotive style filters are made of paper and when water hits them they swell up and shut off the fuel. They don't work in equipment at all. Dresser used to have one that was brass on the inside instead of paper. You might check with a Komatsu dealer. Your D20 should have the strainer in the banjo that connects the suction hose fitting to the transfer pump. Good Luck!
PC150-5 stalls in high only Having a similar problem with a PC150-5. It runs fine in every mode except high, which the boss likes to run all the time if possible. Machine is not showing any codes, otherwise operates fine. Soon as you switch into high mode, the rpm goes up, then it acts like someone cut off the switch, it doesn't stumble or lug, it's like the engine completely shuts off, the rpm drops considerably, then surges up to high rpm again. Almost like an electronic speed governor is shutting the machine down, or some rpm sensor is freaking out at the high speed. Works fine in every other mode. Good power, no smoke, clean exhaust, normal operation. Except high mode. Any ideas? William from Georgia.
Your description sounds like the throttle motor linkage is out of adjustment and pushing the lever on the governor too hard against the stop. The computer senses the amperage going up, because the motor is increasing power to reach high idle, and the black box cuts the movement back. Turn the machine key on but do not start the engine. Have someone turn the throttle dial up in high mode while you watch the motor and governor. If it hits the stop and pulls back you know you have to adjust the linkage rods. Good Luck!
Tried the fix today, shortened the throttle linkage about 3-4 threads. Now the machine runs fine in high. Not sure what happened to make this problem start though. Jam nut was tight and didn't see any mechanical damage. Either way it worked like a charm. Thank you so much for your advice, William
There might be a problem in the motor gear box. They use nylon gears in there and I've seen them jump a tooth. As I remember all the gears are keyed so you can't just take the box apart and time the gear so you are past the bad spot. You should be fine for quite awhile though as the overload function usually keeps the gear from being totally destroyed. Glad to hear you fixed it.
Thanks again, will have to give the boss a heads up on the plastic gear. These forums are such a great help - I take care of every piece of equipment we have, and its nearly impossible for one guy to have documentation and experience on 15 different brands/mfg of equipment both domestic and foreign. I can't imagine what the cost would have been to have the machine picked up and hauled to a dealer for repairs, when one simple adjustment someone here already knew how to do - put the machine back in service. We are having a very difficult time even staying in business (I'm a mechanic, so if the equipment gets sold or repo'd, I'm out of a job for sure) and the ability to do repairs like this without giving up and sending it to the dealer - is sometimes the difference in having a job and being unemployed. Thank you again for sharing your time and knowledge, William
hello john i have a problem similar to the one discribed here in this post ...its a komatsu pc200lc-6 ...starts and run fantastic ..after 5 or 10 min unit slow down and stops but the engine still runnig ok ..no respond on the joysticks but engine still ok and revup when joystick are applied ..do you think maybe its a fuel delivery problem ?? ..no black smoke at all when is running .,... please i need help i have the unit in the garage like 2 months and nothing ..i do everything possible with no positive results ...best regards joe gonzalez ..colombia south ameriica
i could use a little more information on what is going on. Are you saying the hydraulics quit working but the engine still runs properly? Did this start right away after you got it out or was it doing it before you put it in storage? Do you know if you have any fault codes on the monitor?
ok heres the situation ..i check monitor no faulty codes , check all the filters and lines , check the little filter in the banjo bolt in the tranfer pump , i changed the self pressure reducing valve and pump merge divider for a new one , i change the cylinders seals , i check the control valve for debris . i polished the spools , i check the pilot selenoids for debris , i check the selenoids bank of 6 switches , dissasemble , clean , and change the accumulator , and nothing ..unit still working as is ...you start the engine , work for about 5 or 10 minutes then joystic stop to respond ..oh i forgot ..i check the switch for the ppc valve lock ..lines etc ..heeelpp
one more thing ...maybe i did not explain very well ...im working in my garage this unit for two months ago to try to fix this problem ...im working in the unit ...since that
heres the order when starts to fail ..first operation to satrt failing is the boom raise ..then arm in and out ..start to move slowly ..then bucket and swing very slow ...undercarriage is the last to fail and then no movm,ent at all ..but you can feel a slight movment in the boom and arm very slight ...
Ok , Its a very old thread but I have the same problem .PC200-6 . mrjoe72 did you work out what was the cause ?