Broken Crank, What to do?

[Hooked_on_HP]

My guess would be that the pump is air locked. Do you know if the dealer tried to bleed the pressure line at the pump.I have even had to fill the suction line up with oil to get the pump primed.
Bill

 

[uofa314]

I hope you are right. They told me it should prime itself. They changed the hydraulic oil and filter and cleaned the pickup screen. The pump being air locked is the only thing that makes sense to me. It seems like there would be air in the lines since they were disconnected. I don't see how the pump could have gone bad in just a few weeks time of sitting there. We are picking the tractor up tomorrow and will try to bleed the lines this weekend. We'll try filling the suction line with oil like you suggested. Thanks, for the tip.

 

[uofa314]

Well, I've been working late this week, so my dad went to pick up the tractor. He says it is running good, except that it surges while it is idling. He says it is a gradual surge. It slowly revs up and then slowly back down and then back up again. At higher RPMs or under a load, it levels out and doesn't surge. I'm thinking its something with the governor. I'll look in the service manual this weekend when I go down to their house to work on the hydraulics, but in the mean time, I thought I would ask on here. Is there a way to adjust the governor? I thought we put it back on the way we took it off. It's basically just a disc that puts tension on a spring that is attached to the injector pump. There must be some way to adjust the tension on that spring? What do ya'll think?

 

[ericher69]

Could it be an air leak in one of the intake gaskets?

Also have you done the basics; fresh fuel, power service type additive, new fuel/air filters?

 

[uofa314]

Went down to work on the hydraulics today. We started it up, and decided to hold one of the levers down to raise the front in loader to see if that would do anything. After about a minute, it started working. I guess it finally got the air worked out of it. The loader and lift on the back are working fine now. The engine is still surging. It runs good at higher RPM's and doesn't surge, but it will not idle at lower RPM's. It slowly revs up and then back down. I'm thinking we didn't get something right with the governor when we put it back together. We may just use it like it is for a while. It runs fine at RPM's where we would use it. Before the rebuild, it smoked a lot more, didn't have good oil pressure, and ran warmer than it does now. Now, it doesn't smoke much at all. I assume that's a good thing?

 

[Hooked_on_HP]

Your injection timing could also be off. Or you could be sucking air. Did you have the injection pump apart or just take it off. Taking it off should not afect the govenor. If your injection timing is off you could damage the motor. If you are sucking air you are also sucking dirt into the engine. Find the problem and fix it.
Bill

 

[uofa314]

Sorry that I don't have much experience with diesel engines, but how can an intake leak cause this? I understand in gas engines that it would affect fuel air mixture, but diesels don't work like that. Also, the air would leak out if anything since this is a turbo engine. We only removed the injection pump, but I could see how that could be off. If the injector timing is causing this, should we add or remove shims? Adding shims will delay the injection and removing them will advance it. Thanks in advance.

 

[SSdoxie]

The spring that connects to the fuel rack has to have slight tension on it even at idle to keep rack in the same position. This spring pulls on a lever in the govoernor that then pushes up against the disc on the governor weights. If you accidentally stretched that spring removing or installing the injection pump it would allow the RPM fluctuation.
Another possiblity is the idle set too low. If the idle stop is set below engine specs, it is pulling the rack back closer than the designed length of the spring. Try turning the idle stop up a little a see where it stops fluctuating then check that RPM versus recommended idle in the manual.
If all the timing gears were lined up correctly and same shims used to reinstall the injection pump, it shouldn't require re-timing but won't hurt to double check.

 

[uofa314]

SSdoxie, after reading your post and going from memory, I'm thinking that we likely stretched that spring. Not knowing any better at the time, we tried to remove the timing gear cover before unhooking that spring. We didn't pull on it that hard, but it probably didn't take much to stretch it. The tractor is at my parents house an hour away, so I can't take a picture. But, I will attach the parts diagrams. Is it possible to replace that spring without removing the timing gear cover? Removing the timing gear cover would require removing the radiator and all sorts of stuff to get to it. I'm hoping it will be possible to replace by removing cover 18 above the injection pump and cover 8 on the timing gear cover. What do ya'll think?