Problems starting a B7100 after a bit of a rebuild

[chetcromer]

Hey all,

First off, I know SOOO much more about my B7100 than I did a couple months ago when I bought it! My mechanic friend and I split my tractor to basically do an overhaul on the clutch and wound up replacing and/or machining just about everything from the flywheel and pilot bearing to the joint tied into the transmission. We finally got everything put back together over the past two days.

Topped off all my fluids, reconnected all the electrical components, and went to start her up. Turned right over and started, but started to sputter and die about 15 seconds later. Won't restart now, and there's a squeak that seems to go along with the cranking while the starter spins.

Immediate thought is a fuel flow problem, probably air in the lines (drained the tank and replaced the fuel filter during the overhaul). Following Vic's directions here on OTT (http://www.orangetractortalks.com/2008/11/how-to-bleed-kubota-fuelinjector-lines/), I opened up the 10mm bleeder bolt at the filter and have fuel flowing clean there. I can't get to the bleeder bolt on the pump itself because of the shroud (which I can remove with enough work, I'm sure), so instead went up to the injectors and opened up the nuts and pulled up the tubes enough to let air out.

When I crank it that way, I get just a little bit of fuel out of one of the injectors (the first one in the line), but nothing that I can see out of the other two. I cranked for about 30 seconds with that result. Occasionally (maybe twice) I get a small puff of smoke from the injector port, and there is a LITTLE black smoke coming from the exhaust, but it doesn't really smell like diesel.

Here's a quick video with the squeaking sound I get when starting.

http://www.youtube.com/watch?v=K5AUxgv1p34

In the video I state that the sound seems to be coming from the transmission, but that was incorrect (heard it better once I got on the other side of the tractor, and seems to be coming from near the fuel pump, but I'm not sure). I DO have too much fluid in the tranny right now (manual said 12 qt, but it overflowed at about 10, so I'll siphon that out soon enough).

Thoughts? Here are a few pics from my recent adventure. Can't wait to get this thing going, and appreciate your ideas or questions.

 

[MagKarl]

You need to follow the bleeding process and get fuel to the cylinders. Skipping the pump plug likely means no fuel to the pump yet. No fuel in means no fuel out. Maybe pull the fuel line at the pump if the plug is too hard to get to?

 

[chetcromer]

I wondered if that might be the case. In the article it stated:

"There are two methods to bleed this system, one using the bleed valve and cylinder head decompression, and the other involves loosening the injector lines from the injectors. Either method is a straightforward procedure."

I wasn't sure to read this as an "either/or" or a "maybe both" statement. To get to the pump, I need to remove a few more pieces of metal that support the air cleaner, so I'll dig into that tomorrow.

A farmer neighbor also recommended pushing a little bit of compressed air into the fuel tank to help push the fuel down the line. He runs larger tractors so I'm curious if this is a no-no with a smaller tractor.

 

[chetcromer]

Whoops... missed this part of bleeding the injectors:

"Once you’ve unseated all the injector lines, open the fuel bleed valve on the side of the injector pump (as discussed above), pull on the decompression knob to relieve the cylinder head of any compression, and then turn the key and crank over the engine."

Just like you said, gotta bleed the injector pump as part of bleeding the injector lines running to the engine.

 

[Stumpy]

The lack of starting is sounds like an air lock at the pump as everyone else has said. Bleed the pump then the two dry injectors and work your way up from there.

That noise sounds a bit odd to me. It's got oil pressure after a second or two of cranking? It could just be gear noise from the starter ring. The teeth all looked good when you had it apart? I'd try turning the engine by hand and see if it still makes the noise. Remove the glow plugs before you do, it'll prevent it from firing and make it easier to turn. If it still makes a squealing sound track it down before you put it back in service.

 

[chetcromer]

I bled a fuel system!

http://www.youtube.com/watch?v=tXAJIqVJFC8

Took some effort to get the shroud off with the loader on (lesson learned - get tractor running before you reassemble entire loader), but once I did it was simple to get to the bleeder bolt for the pump. Definitely had some air pass through there... got that clear, which then started getting flow to the injectors, which then... ignition! (is that what you call it in a diesel?)

My squeak is still there; seems to be timed to the engine. The more I listen, I think it may really be coming from the tranny area, even with the clutch fully disengaged. My tranny fluid is too full, so the next job is to drain that down a bit - is there something in there that would be running with the clutch disengaged? I'm thinking it uses that same fluid for the rear lifting arms?

Also, I mistakenly broke lose the entire injector when loosening the top nut. I got some air bubbles out of that so tightened it down and I think they're gone - is there a seal or anything in there that once broke needs replaced?

 

[skeets]

Could the noise be coming from the pump, maybe the lift valve bypassing

 

[chetcromer]

Noise was coming from the rear hydraulic lift. Not sure if it had air in the line or what, but once I raised and lowered it a couple times, the noise was gone. Engine all back together, clutch works like a charm, time to take it for a test drive.

UGH! Three laps around my property and my steering just went out. Completely. The wheel just spins. I was able to turn left but not right for a bit, but now they're both gone. I can turn the tires to the left, but turning to the right is VERY stiff (just shoving on the tire). No power steering here.

 

[kubotasam]

Noise was coming from the rear hydraulic lift. Not sure if it had air in the line or what, but once I raised and lowered it a couple times, the noise was gone. Engine all back together, clutch works like a charm, time to take it for a test drive.

UGH! Three laps around my property and my steering just went out. Completely. The wheel just spins. I was able to turn left but not right for a bit, but now they're both gone. I can turn the tires to the left, but turning to the right is VERY stiff (just shoving on the tire). No power steering here.

Don't force the steering box. The ball nut must have come apart. You can ruin very expensive parts if the ball bearings get jammed between the gears. Get that steering box off the tractor and rebuild it.

 

[alchemysa]

If the engine has not been run for a long time its sometimes useful to remove and completely drain the fuel filter. Otherwise you'll just be 'bleeding' a pint of very poor fuel into the pump, injectors etc.