140G problems

[Linkbelt HC]

Our fleet's 140G has developed a stalling habit of late. My partner and I have chased down the usual suspects, fuel, filters and air draws to no avail. The machine will run fine and even at full rpm, working until suddenly the engine dies. We will then have to wait 5-10 mins before restarting and everything is fine again. Should I look to the lift pump next? Any help would be appreciated.

 

[stray cat.Inc]

A couple of things I've come across, are a plugged fuel cap vent, something in the fuel tank. The fuel cap problem, when the engine dies, loosen the fuel cap, you should hear air rushing past the threads. A slight swooshing sound. Usually with a piece of plastic in the tank, the machine won't have to sit long before it will start. As far as your question about the fuel transfer pump, or lift pump as you called it. It's a little gear pump in an aluminum housing on the very front of the fuel injection pump housing, there is a little pin that engages the gear on the pump shaft, they are very tinny and can wear thin enough to shear off. But to check that potential problem, you need to remove the fuel injection pump. Keep in touch so I know how you make out. Good luck

 

[smoothoperator]

If problem comes late in the day, when fuel level in tank gets low, it could be the transfer (lift) pump. Remans are reasonable, but pump can be kitted cheaply by replacing the three one-way check valves within the pump housing. Crack loose lines, then remove pump mounting bolts, move pump away from injector pump housing, then finish removing fuel lines. This will keep you from getting a shot of fuel in the face when pushrod jumps. (from experience) If machine falls flat on face after a high demand fuel situation, long hard uphill, or just extended heavy load, check for restriction in your fuel tank/ lines leading to your first filter or water separator. I had a sludge/slime buildup in the bottom of my tank near the fuel shutoff. Popped the line, opened the valve, and the fuel just dribbled out. After cleaning, I think it would freeflow over a quart per minute. Another place to look would be fuel cap venting. Could be one of these, may not be any of these, but they may be things you haven't tried but might want to.

smoothoperator...free advice is worth every penny

 

[smoothoperator]

I thought your transfer pump might be run off of a cam lobe on the side of the injection pump. I guess it might be different than the ones on our machines. Sometimes you can have good power until your filters are sucked dry. Machine dies, filters slowly fill again, and you have good power until process is repeated.
Good luck, I'm sure you will get lots of help with this one.

smoothoperator

 

[rare ss]

If its not the fuel cap (I'd be pulling it apart an cleaning out the vent first) as smoothoperator mentioned, try blowing some compressed air back into the tank from the fuel filter, should hear it going into the tank and look inside for any snot in the diesel getting stired up, but I'd be thinking it's the lift pump, if you have access to a gauge there should be around 32psi at the fuel pump, there should be a plug around the delivery lines in the fuel chamber on the injection pump, another thing I've found once is some people replace the fitting on the return line back to tank on the fuel pump without relising that its an orifice fitting to get the correct pressure from the lift pump, if a regular fitting in its place you loose too much flow back to the tank hence don't have enough pressure, graders and dozers seem to run fine without much help from the lift pump as the fuel is gravity feed into the injection pump, other machines with the fuel tank mounted lower won't run at all once the fuel drops abit

 

[stray cat.Inc]

140g

The "G" Series Motor Graders have Sleeve Metering Injection pumps. Easy to recognize, the side of the pump has a flat plate bolted to the housing.

 

[smoothoperator]

I remember searching for what system I had on my '84 140G, and I thought it was called a "new" scroll system in our service manual. I think all of our G series (72V) after 1984 had a similar system. There were other systems shown in the manual, so I guess they were used, but we didn't have them. My 143H 3306 had the transfer pump on the side, too. Probably should identify your system by looking in a service or parts book that covers your serial number and series(72V etc.) and your engine model (08Z etc.,I think) Lots of good ideas coming in. I think you will find your bug.

smoothoperator...yes, I have no idea.

 

[Bluetop Man]

Sounds exactly like a 450C Deere dozer I had once. There was an electric solenoid on the fuel return line that would shut the injection pump down if return pressure dropped enough. Usually a plugged return line. Don't know if CAT has the same thing on graders. I've never had one to shut down like that before.

 

[Linkbelt HC]

Good Morning;
Thanks for all the quick advice. I will have the machine hopefully pulled in the shop this week so we can begin troubleshooting it. I will certainly start with the fuel cap and work from there. Part of the initial problem was between the time of the trouble call on the radio and the time it takes for me to get to the operator the machine is already restarted. My machine serial number prefix is 81V1xxx and I will check my parts book for the pumps location. I will certainly report back on the problems we find.

 

[Bluetop Man]

Also look for a problem or sensor malfunction in the emergency shutdown system if the machine is so equipped. Good luck.

 

[250c]

The advice on the plugged return line is right on the mark for a engine acting like this. I had a crane that gave me fits until I found a plastic cup that would occasionly work its way over the fuel pickup in the tank.

 

[carrier762]

This is a fuel cap problem I have worked at cat for 10 years and now work for a company that is almost all graders and the fuel cap is always the problem cat sells a kit to rebuild the caps

 

[Queenslander]

cat sells a kit to rebuild the caps

This is always included in the 500 Hr service kits we buy from our CAT dealer.
Cheers, Greg