Bleeding Fuel Systems

[Ozarker]

There has been some discussion about bleeding fuel systems after running out of fuel but I have seen no mention of the number one most important tool for that purpose....a tubing wrench.

For those who have never done it before, the tubing wrench is designed specifically for the nuts on the ends of fuel and brake lines. It is designed to make maximum contact with the flats of the nut to prevent rounding off that thin walled nut. An open end wrench doesn't make good enough contact with the flats of the nut and will round them off. Then you'll end up using vise-grips to get them off.

Get one the correct size for the nuts on your fuel lines and throw it in the tractor mounted tool box. That is where you will need it to be when you run out of fuel in the field.

 

[cstocks]

Thanks for the good tip, Ozarker. I didn't know that.

 

[hazmat]

Also known as a flare nut wrench.

Link at <A target="_blank" HREF=http://www.sears.com/sr/product/summary/productsummary.jsp?BV_SessionID=@@@@1221778795.1028576108@@@@&BV_EngineID=ccieadcflgiedmgcehgcemgdffmdfin.0&vertical=SEARS&bidsite=&pid=00942013000> Sears </A>

 

[RoyJackson]

I don't know about your tractors, but the Deere manuals are pretty specific about not bleeding the system. The injection pump is self bleeding.

I've bleed diesel systems when I replaced fuel filters on the old GM 6.2 liter truck engines, but there was a procedure for that.

Self bleeding systems shouldn't be touched, IMHO.

 

[Ozarker]

You're absolutely correct. If your manual says not to bleed out to the injectors then you shouldn't do so. My Yanmar manual says to bleed to the injectors if it is run dry.

 

[normde2001]

Yanmars are not that sophisticated and have to be bled. They also have a procedure for it.

 

[cowboydoc]

They certainly are self-bleeding Norm. Some of the older ones may not be, heck none of them used to be, but the newer ones on all the lawnmowers and tractors are self bleeding.

Also I've never used one of the special wrenches for bleeding and have never stripped the head off. I'm not saying it's not a good idea by any means. It surely is. If there's a tool for it then if you want to buy it that is the best way to go. I'm just saying if you don't have it just be careful and don't twist so hard that you strip it off.

 

[DavidInNH]

I'm planning on changing the fuel filter on my L48 this weekend as part of the 400 hour service. Am I going to need to bleed the system.

 

[RoyJackson]

"I'm planning on changing the fuel filter on my L48 this weekend as part of the 400 hour service. Am I going to need to bleed the system."

What does your Operator Manual say?

 

[karmakanic]

Hi David

Not if your L48 is like my L35. I just did the same thing (400 hr service) this weekend. The fuel filter was in a small clear plastic cannister. There is a shut off valve above, but I found that some fuel flowed out of the housing even with the valve turned to the off position. I just hurried and switched out the paper filter element while the fuel dribbled. Made a mess, but after finishing the service, the tractor started first hit of the key.

HTH
Dave Perry aka karmakanic

 

[Bird]

<font color=blue>Am I going to need to bleed the system.</font color=blue>

Probably not, but as has been stated, your Operator's Manual should tell you. It was not required on by '99 B2710 and since the L48 is a newer model, I doubt it's required on that either. However, my '95 B7100 manual did have instructions for bleeding it, and I had to do it twice in the time I had it. The first time was here in the shop building at the house when I got water in the fuel, and like Cowboydoc, I didn't have a tubing wrench (which is without a doubt the best wrench for the job), but I did have open end metric wrenches that fit. The second time was in a hayfield nearly 10 miles from home when it ran out of fuel (no fuel gauge and a neighbor was using it to pull a hayrake while I was doing the baling with his bigger tractor), and all I had was an adjustable (Crescent) wrench. It still didn't take 10 minutes and didn't damage anything.

 

[DavidInNH]

What - read the manual?

Good idea, I'll take a look tonight.

 

[DavidInNH]

Thanks - now that you mention it, another thread mentioned using a "full body condom" for changing the filter. Maybe they didn't have a shut-off valve (or didn't see it).

-david

 

[DavidInNH]

Hmm - when I was shopping for tractors, the JD salesman made a big deal about them being direct-injected vs the Kubota system. According to him, there were all sorts of wonderful benefits - you didn't have to bleed the system after running out of fuel and they started easier than K's did in the cold. I haven't had any problem with cold starts on my machine nor have I seen any discussion of either of these issues here. I wonder if his information was just way out of date.

-david

 

[Bird]

David, to change the fuel filter on either of my Kubotas, the shut-off valve at the filter worked, and I didn't have to bleed lines; just had to loosen one 10mm bolt to let the fuel filter refill on the B7100 and not even that on the B2710. And as far as direct injection vs. indirect injection, that has been discussed at some length in the past on the forum and quite frankly, I don't know enough to even have an opinion as to which is best. Of course, I never used my tractors in subfreezing weather, and I never had any starting problem as long as I had fuel in the tank (without water)./w3tcompact/icons/laugh.gif

 

[ns_in_tex]

Does anyone know if this is good or bad? Some years ago I ran my larger tractor out of fuel while I was closer to the dealer than home. Had never bled the fuel system on this tractor. Added fuel & it would not start. Dealer sent a tech over, he pulled a little plug in the intake manifold, squirted in some WD40 & told me to crank. It started & he kept squirting until it ran on its on. Never had occasion to try it since. It seemed awful simple.

 

[RoyJackson]

"Does anyone know if this is good or bad?"

Is that tractor still running? Then it must not have been bad.

I don't know the composition of WD-40, but it is a petroleum distillate (as is diesel fuel). Since it sprays in (therefore is atomized), it probably got the engine started enough to pull the fuel into the combustion chamber. Not an optimal way to do this, but for a road fix, seems like it worked pretty good!

I guess you could do this with ether too, but ether is a big No-No!!!

 

[Turfman]

Last time I checked the propellent on WD 40 was propane. I have used it to start mowers, but I'll be darned if I'd use it to start my expensive diesel tractor. I fear that using propane as a temporary fuel might do it in.

Turfman

 

[Ozarker]

It's bad......................... I would immediately start kicking a "techs" a$$ if he pulled that shade tree crap on my equipment because he was too lazy to bleed it correctly.

He used the wd40 as fuel until the fuel lines self bled. But he ran the risk of doing serious damage to your engine. A diesel engine is compression fired and the fuel is injected into the cylinder at a precise time in the compression stroke. By spraying WD 40 in he was introducing a fuel/air mixture at the beginning of the compression stroke that was probably igniting too soon. I suspect the engine was running very rough and knocking while he was spraying.

 

[bgott]

The hot rod diesel boys are using propane injection as a performance enhancer. I hear what you're saying about pre-ignition, I'm kind of curious on how they are doing it and not grenading the engine. I've been known to use WD40 to start engines. I figure it's a little easier on the engine than ether. When I was younger every diesel powered vehicle you came in contact with had three or four empty ether cans in 'em. They never had a full one when you needed it.