tricks to getting the fuel system bled?

[escavader]

I dont mean to ask in two different places,but i wanted more ideas .I changed the two inline filters on my little kubota,and now i got alot of air,ive bled and bled it runs ok for the first 1/2 hout then flutters and gets worse and worse.Mt book says simply turn on the key.... dont work,my neighbor who is a diesal mechanic,and i have been cracking the injector lines to get it out.He explained sometimes a system can be a pain,and takes alot of trys.He sprayed either around the filters and checked them out he said he thought they were fine.It is improving i guess,but what a pain.He even has told me a story about pressurizing a fuel tank to force the fuel out,on a dozer.So any body got a trick up their sleeve?I bet ive cracked them lines 20 times now.If this is what maintanance is gonna get me ,ill run it til it puke
whats your advice?
ALAN

 

[Dirthog]

If it runs for the first 1/2 hour then the system is bled out already. You have a leak someplace and it is sucking air or the supply line is sucking shut.

 

[caddelma]

If it runs for the first 1/2 hour then the system is bled out already. You have a leak someplace and it is sucking air or the supply line is sucking shut.

Had the same exact problem on my Lenar. Ran for a little while then lost power. It was either a blockage or air leak (leaning toward air leak). In my case the shutoff valve under the tank was very loose (finger loose), but not loose enough to leak fuel. Tightened it all up and been running fine.

 

[Soundguy]

I also think that if it runs for 1/2 hour, it is 100% bleed. You may have an air leak at a fuel filter.. perhaps bad oring.. Or your fuel tank is not vented and is creating a vacume.. or fuel line blockage.. / valve blockage.. etc.

Soundguy

 

[escavader]

I think you guys are right.Im gonna put different clamps on the fuel filters,i dont like them wire ones.THANKS
ALAN

 

[kevincook]

Does it run normally for the 1/2 hour or is it still running rough. The fuel lines can be a real pain sometimes. If it runs normally at all rpm's for 1/2 hour then you probably have a leaking line.

Kevin

 

[DieselPower]

If all else fails and you suspect a air suction problem in your fuel system take a trip to your local Caterpillar truck dealer. Ask to buy a special service tool that is called a fuel sight glass. It is basically a fitting with a clear sight glass in the middle of it. It hooks in line with the fuel supply line to the injection pump. If you see bubbles in the glass you have a air suction problem either at the fuel pump or before. If your engine has a primer pump that is also a suspect item. I have replaced alot of fuel primer pumps over the years that were fine one minute and started sucking air the next, then were fine again. Air being sucked into your fuel system can be a nightmare to troubleshoot if you don't plan out your troubleshooting plan in a systematic plan. Good luck.

 

[escavader]

Just an up date ,I changed the clamps,seems alot better,doesnt seem to be any air now.The tractor doesnt seem to sound the same on all cylinders,of course i know how it always did sound.Its been about 20 hours on the meter,since i last posted.Every now and then i can smell raw fuel coming through the exhaust.Whats going on? I got 3 months on the warrenty.Can you give me an answer or should i truck it to the dealer.Faulty injector pump? bad valve?I really need this tractor,to finish up projects before ground freezes[any time now]
ALAN

 

[Soundguy]

If i were coming to an end of warranty coverage, and i had -ANY- questions as to operational correctness.. then it most deffinately would get trucked to the dealer.. even if, in the end, it was just a day of driving and a clean bill of health.

Soundguy

 

[Dirthog]

If you can smell raw fuel comeing out the exhaust you have a cylinder that is not fireing properly either you have low compression in one cyl or more likely a bad injector.