M8200 injector bleed

[shootboss]

I have an 18 year old M8200 which I think has air in the injector lines. I cleaned the bowl and foolishly didn't refill the bowl with diesel. I've looked at a lot of videos on bleeding the lines but my tractor doesn't look like any of the ones featured in the videos. They're all smaller models. Mine has a primer pump on top of the fuel filter. There are 4 injector lines in a row on the right side of the engine but I suspect this is the injector pump if I'm not mistaken. I loosened the two on the end I could get off and fuel come up. What is the process for correctly bleeding the injectors?

Thanks in advance.

Ben

 

[North Idaho Wolfman]

First open the jet start valve on the front of the injection pump crank for a min or so, close valve.

The Crack the lines at the injectors to bleed the air out, crack the lines and crank till you get good fuel with no bubbles.

Tighten lines

 

[Bulldog]

Actually you should never fill the bowl with fuel. When you do that the fuel isn't filtered and can stop up your pump or injectors.

It's really easy to prime your system though. Loosen the banjo bolt where the line goes into the injector pump. Then use your primer button on top of the primary filter. When fuel comes out of the banjo bolt tighten it down and start the engine. This is how I do my M9000 and works every time. I've never had to open any injector line to get mine to crank.

 

[North Idaho Wolfman]

Actually you should never fill the bowl with fuel. When you do that the fuel isn't filtered and can stop up your pump or injectors.

It's really easy to prime your system though. Loosen the banjo bolt where the line goes into the injector pump. Then use your primer button on top of the primary filter. When fuel comes out of the banjo bolt tighten it down and start the engine. This is how I do my M9000 and works every time. I've never had to open any injector line to get mine to crank.

110% agree with not prefilling the filter, good catch.

Couldn't you get the same results opening the jet start valve which bleeds all the incoming lines out to the vent?
And as long as it wasn't cranked then air would not be in the injection lines, but I'm running on the assumption (maybe a wrong one) they already tried to start it and got air in those lines.

 

[sheepfarmer]

Where did the notion of prefilling the fuel filter, or the water separator if there is one, come from? I had heard it too, but I don't remember where. When is it a good idea? Techs and my owner's manual for L 3560 said it wasn't necessary, and after seeing the flow chart for the fuel it is real clear why it is a bad idea. Keeping in mind that I jumped from a Ford 8n to this common rail tractor....

 

[D2Cat]

Sheepfarmer, who knows where it came from? I think it came from folks being in a hurry, not ever considering what could possibly get into the injection pump, not having a problem then telling how it worked!

So folks hear it, and repeat it...and life goes on! Only when a problem arises is there a consideration of WHY put unfiltered fuel in an engine? Is it really bad? It was clean when I put it in there! (but it wasn't)

My 1966 Case 730 (diesel) has a primary, secondary and a final fuel filter. Some engineers thought clean fuel was important way back then!

 

[North Idaho Wolfman]

Another member on the forum did that, it's NEVER a good idea to do it because the fuel that you prefill it with is not filtered.
And same with any other filter.
Most if not all the newer Kubota tractors have the ability built into the system to burp the air our automatically without having to much of anything.
It's only in the event that something wasn't done per instructions, like cranking the engine with air in the filter housing, that it becomes an issue.

 

[Bulldog]

110% agree with not prefilling the filter, good catch.

Couldn't you get the same results opening the jet start valve which bleeds all the incoming lines out to the vent?
And as long as it wasn't cranked then air would not be in the injection lines, but I'm running on the assumption (maybe a wrong one) they already tried to start it and got air in those lines.

Wolfman, I'm wanting to look into this jet start valve. I had never even heard of it until it was brought up the other day on here.

Is that what the little knob it called by the injector pump?
My L3000 and my trackhoe both have the knob but my M9000 doesn't.

 

[007kubotaguy]

Bulldog
Your M9000 should have a bleed screw on it. It is on to front of the injection pump and not on the side like your L3000. A little hard to see but it is there.
Lance

 

[Tx Jim]

I've prefilled fuel filters with diesel fuel for yrs & never had a problem. I utilized "filtered diesel" drawn straight from my overhead storage tank that has a filter on the outlet. Once fuel is poured in vehicle filter won't the largest majority of the fuel in the filter get filtered before it leaves the filter to go to IP?

Back in the 70'-80's when I drove a 18 wheeler I utilized auto trans oil to fill fuel filters when changing them. I never experienced any problems doing that either BUT I wouldn't recommend utilizing trans oil on newer common rail fuel systems.

 

[North Idaho Wolfman]

Wolfman, I'm wanting to look into this jet start valve. I had never even heard of it until it was brought up the other day on here.

Is that what the little knob it called by the injector pump?
My L3000 and my trackhoe both have the knob but my M9000 doesn't.

The purpose for the jet start valve is to add a low resistance path that vents air and fuel back to the tank to "burp" the system, while still providing fuel for the injection pump to use.
If you open that valve anytime you open the system before the injection pump it will automatically cause any air in the lines / filters / water separators, to burp back to the tank and not be forced into the injector lines.

Like 007kubotaguy said the Jet Start valve is on the front of the injection pump on the M9000.

 

[Bulldog]

I'll be looking for that for sure. I love that on my little tractor so if the big one has it things will be much easier in the future.

This is just another reason OTT is the best site on the net, brothers helping brothers.