I have a Komatsu D75S-3 and am having problems getting fuel to the filter. Strainers clean at bottom of tank. I've had the float tank off and cleaned it. Not sure why I can't get fuel to filter? Machine has a Cummins 220. Can I get a new float tank from Cummins? It would be cheaper than Komatsu. Any ideas guys?
Yair . . . Joe-Loader. The float tank apparently is to prevent the possibility of fuel getting into a cylinder through the injectors from the head pressure in the main tank. In my ignorance I bypassed one on a 65 dozer and apparently copped a good serve from a Cummins trained tech. who fitted a new one some years later. . . . we had no issues though and, for all those years the engine ran fine. Again in my ignorance I have fitted a Cummins in a trawler and we provided the standard gravity day tank and the boat ran for many years until it burnt after a gas mishap in the galley. I think you will find the tank and fittings are Komatsu parts and I believe the Komatsu engines do have slight differences to the fair dinkum Cummins. Cheers.
Scrub pulled- any ideas why I wouldn't be able to get fuel to the filter? I have enough fuel in the tank. I'm kind of baffled! Thanks for the help!
Joe, the "float tank" operates very much like the tank on the back of most bathroom toilets. Simply a "float" that is connected to a valve. When fuel level drops float moves down and opens the valve. When float raises up with the fuel it shuts off the flow of fuel. Not exactly rocket science! If you have flow of fuel from the fuel tank going to the inlet of the float tank but no fuel in tank that simply means there is something plugging the valve the float is connected to so no fuel get in the tank. Could be something binding the linkage but should be easy to scope out if you open the tank. Just as a quick test take the fuel line that goes from the float tank off at the tank and stick it in a bucket of fuel and after priming the fuel filter(s) try starting the engine. If it picks up the fuel and runs right then pull that float tank off and open it up and have a look-see!
Thanks ks hansen I primed filter housing buttoned it back up got engine running hoping it would pull fuel. No such luck! Once fuel ran down she shut down. Tried this twice! Thanks for the help appreciate it!
Well that's a good sign, engine and injection pump are working. Just need to get fuel from tank to suction line for inlet to primary fuel filter. Start at the fuel tank and see if fuel come out of the tank with line disconnected. Then check to see if fuel is getting from the tank to the inlet to the "float tank". If it is getting that far pull that little tank and take it apart and see what the problem really is, probably some dead bug in the float valve!
Make certain the fuel control isn't shut off. I was at an auction several years where they couldn't get a Komatsu track loader started that was running the day before. They were boosting it and pouring ether to it and finally someone said to double check the fuel shut off wasn't the problem. It had some kind of odd system but after they played with it the machine started right up. I'd guess it sold for a lot less after seeing them #$%^&@ with it for over an hour!
Getting fuel to float tank I know this. I've drained the fuel out of the float tank and it was clean. Machine sat for over a year, so I was very glad how easy it started. Thanks for the help appreciate it.
Where is this located? Would machine start after I primed it if this was off? Machine sat for a year and that seems to be the biggest part of my problem! Thanks for the help!
had trouble with mine for over a year. it had a small piece of an o ring in the seat that would restrict it just enough under heavy load that it would quit. found it by accident now it has more power in sec gear than it ever had in low since i owned it. 3 different techs tried to find it even me? 160 dollar manual did not have it in it.
I don't know where it is but I think the loader was a D75S as well but an older one. It's up by the dash somewhere and you have to turn or pull it or something and it has to go all the way.
mine is located on the left side of machine down under the transmission and hydraulic filters fastened to the frame basically on the frame BELOW the fuel tank. 4 bolts i think held the top on. have to look at that old man and his memory.
I don't think mine has one. I have only ever shut off fuel under the tank. Getting fuel to float tank, but not filter.
Time to open float tank and figure what is blocking outlet.
Yair . . . Over the years of playing with a couple of different 65 dozers both had problems with rust in tank which would tend to restrict/block the rather elaborate fuel shut off valve. Cheers.
what he said
Agreed! No other options.
I want to thank all you guys for your input I really appreciate the help!
When you do pull this and open it up try to get some pictures so others will understand what this looks like and how it works.
This a photo of the tank
This a picture of the Float valve
I had to clean the tank there was a lot crap in there and it was hard to get clean. Fuel still wasn't gravity feeding to Filter even after I put another 15 gallons of fuel in just to be sure I had enough fuel in the tank. Which ended up being 3/4 of the way full. I primed the filter buttoned it back up started the machine and she kept running. Now I have a weak reverse, so going to search and see what I can find on that, so I might be starting a new thread. I can't buy a break anymore.
Well the fuel should NOT gravity feed to the filter, that is what the float tank is designed to stop. I noticed that just to the right of the 90º fitting on the bottom of the tank in the first picture there appears to be a drain plug. If it was me I would take this plug out and drain some fuel out of the tank at every oil change at the minimum. And as you found crap in the tank just now I would be doing it at least a couple time a week till it keeps clean. The other thing I would look into is how bad the main fuel tank is, it may need cleaning also.
Those are good ideas! Yeah I agree the tank is probably a mess too. Thanks for the help! You know anything about power shift transmissions? Mines weak going into reverse!