I just bought this 300-7 and the first job I put it on it fails miserably on me.... Here's the deal, This machine is an '04 has 6500 hrs, After about 20 min of running it slows down to the slowest old dinosaur you have ever seen, it looses 80% of the track power and takes about 30sec to raise boom high enough to load a truck (all functions are affected) The boom/stick still seems to have all of its power but looses speed..... The tracks are weak in my opinion all the time but really gets noticble when warm, The fluid is only about 170* pump does NOT squal or howl or growl in anyway until after about 45min of running and then the pump picks up a minute noise and at that time it looses almost 100% of its speed For what it's worth, I bought a pair of machines from the same dealer at the same time and both are a long ways from what they was supposed to be so I doubt the fact that it was a perfect machine before it was loaded to come to me Any ideas other than replacing the pump ? PJ
On a side note, what is the difference in the A E B L work modes work modes? There is also a button with the writing rubbed off of it on the top row of the control panel, I am guessing it gets used a lot but I don't know what it is supposed to be. Btw, I'm a CaT guy by heart but thought I would try komatsu again.......so far I'm not too happy lol. Pj
#1 is to check rpm's and then check track speeds in med. Settings.
The A= Active mode is for heavy digging, E = Economy mode for normal digging and best fuel ecconomy, B= Breaker mode for using a breaker, L= Lifting mode for lifting, in the L mode it cuts your revs down, slows hyd speed but gives more control and increases power by about 7% from memory. If its in the L mode it will be slow for normal digging work and have seen operators complain that their machine wont perform and dosnt have enough revs and all thats happened is they have put it in the L mode. Would be handy for u to get an operators manual cause that will explain all the modes and buttons etc, hope its a simple fix. Cheers RDG.
I'm afraid it's not as simple as a button, yesterday the machine surged a couple of times and then has not moved since, hydraulic level is fine, I'm thinking we have a weak pilot pump does anyone have a schematic they can post up real quick ?
After a few hours of tinkering finally figured out it had a plugged pilot return line.....why it was plugged is beyond me, I'm afraid I have some hoses deteriorating on me, the machine is 10yrs old so it's bound to happen sooner or later,.......I'm still not totally convinced the pilot pump isn't getting weak as well, can anyone send me test procedure ?
What was it clogged with is the bigger question! it could be a very bad sign of things to come, i would have oil samples done if i was you.
Start troubleshooting from the cheapest possibility to the more expensive. Air and fuel filters are the first item affecting power and speed. After that you need to check for fault codes on your computer. Once all the easy stuff is exhausted is when you start pulling hard parts. Do you have a real Komatsu engine or a Cummins copy?
Trevor that is my thoughts as well. John, it looks like an 8.3 cummins but its a komatsu. Pj
I haven't seen a Dash 7 that wasn't a Cummins clone. The Komatsu engine would be a SA6D108 I believe. Komatsu makes Cummins engines in Asia under license so it could be a Cummins clone. The reason I ask is because the Cummins engines have an in line fuel strainer instead of the banjo bolt strainer in the priming pumps of the Komatsu engines. Frequently people think they have a problem and go down to the Napa store and buy an in line filter and install it instead of the strainer. The original strainer is just a brass screen inside and can be cleaned. The automotive filters are paper and when any water hits the paper the cells in the fabric swell and close off the flow. The computer is set up to drop the flow of the pumps in order to keep the speed of the engine up. The operator complaint is that the engine sounds the same but the machine gets slow and weak. You can clean the strainer with a little air pressure in the reverse direction. The filters are throw away items. Just a thought of something to check before you spend lots of money. Good Luck!
just realized i never posted a resolution to this and it irritates me when ppl dont reply with a fix, it was the main pumps that took a **** on it. and ran trash through the entire system, smoked the swing motor, the lolipop tree was totally plugged, got into the track motors and it even ran through the pilot controls...... extremely costly fix! pj