bleeding air from fuel system

dpalombaro · Post by **dpalombaro** » Sun Jul 25, 2010 1:30 pm

i am giving some much needed care to a 63 super dexta which was inherited. not sure when the last time it was serviced but anyways, i changed fuel filter, valve cover gasket , oil ..... i am having trouble getting started. i get fuel through the filter to the injector pump but not up and out of the injector lines. could i have air trapped in injector pump? whats the best way to fix this? it did run before i started to fix it up.

GERRY · Post by **GERRY** » Sun Jul 25, 2010 3:45 pm

Hi if it did run before you changed the fuel filter then it is most likely to do with bleeding the system , there are two bleeding screws on the injector pump have you bleld these, if not then open them one at at time and pump the lift pump untill the diesel runs clear without any air bubbles,tighten them up an then give it atry. gerry

dexta61 · Post by **dexta61** » Mon Jul 26, 2010 2:37 pm

I had the same problem when I ran out of fule on my 61 dexta.

Now I have read the first answer and it may be that a dexta is different from a super dexta I do not know.
But I had two bleeding screws on the fuel filter and one on the fuel pump.
Procedure was to open the lowest bleeding screw on the filter first and pump with hand pump all the air out of it. Next is the highest bleeding screw and pump the last air out of the filter.
now I kept on pumping with the handpump and above it on the injection pump below the first line to the injector (counted from the front of the tractor) there is a screw open slightly, because in my case teh diesel gushed out. When the air was gone in the injection pump, it was start as usual. just a 10 min job.

dpalombaro · Post by **dpalombaro** » Mon Jul 26, 2010 9:50 pm

i am still getting air at pump. it seems when i push down on primer pump that it may be sucking air through bleed screw then releasing it with pumped fuel. maybe i am just seeing things, i will keep pumping until no bubbles. would the air trapped in the pump keep me from getting anything through the ijector lines? it seems like nothing at all is coming out when i crank after tightening the bleed screws

dexta roadless · Post by **dexta roadless** » Mon Jul 26, 2010 10:55 pm

Then you probably have a leak in one of the valves in the primer pump. it will work suffiently when tractor is started, but when bleeding it will suck air. Just take off the top of the primer pump and blow carefully out any dirt from the valves and check that they seal. Remember that the diesel trough there is not filtered. It is a 10 min job.

terry274 · Post by **terry274** » Mon Jul 26, 2010 10:58 pm

Sounds like you may have fittings that are allowing air to enter. I had the same trouble. I replaced some of my copper line and used new ferrules (olives or compression fittings). Once I did that I have not had any fuel supply problems.
Terry

Post by **Brian** » Tue Jul 27, 2010 7:59 am

Have you checked that fuel is getting to the lift pump? Check that there is a good flow from the tank to the pump.

GERRY · Post by **GERRY** » Tue Jul 27, 2010 9:05 am

The dexta isnt as a rule very hard to bleed if you have done alll as has been said of the previous posts then you might have to try something eles, was it a hard starter before, did it need heat to start or did it fire up right away when cold. mybe if you could get someone to give you a tow, just to get her going, keeping safety in mind as always when doing this , Gerry

dpalombaro · Post by **dpalombaro** » Fri Jul 30, 2010 10:09 pm

Brian wrote:Have you checked that fuel is getting to the lift pump? Check that there is a good flow from the tank to the pump.

No its not. the pump isn't shooting any fuel out with the line un hooked. I got a new fuel pump and it seems to bottom out internaly before getting tight against the housing. I dont have a parts manual, the new pump is S.60443 to replace 957e9350b from yesterdays tractor.com. are there different pumps? are there any tricks as far as positioning?

dpalombaro · Post by **dpalombaro** » Sat Jul 31, 2010 5:11 pm

dpalombaro wrote:
Brian wrote:Have you checked that fuel is getting to the lift pump? Check that there is a good flow from the tank to the pump.
No its not. the pump isn't shooting any fuel out with the line un hooked. I got a new fuel pump and it seems to bottom out internaly before getting tight against the housing. I dont have a parts manual, the new pump is S.60443 to replace 957e9350b from yesterdays tractor.com. are there different pumps? are there any tricks as far as positioning?

ok its in. i was not pushing hard enough at first. i am now getting a little fuel out the injector lines not a steady stream just spits of fuel is that normal, but still wont start. can i give a little shot of starting fluid? any other ideas?

Bensdexta · Post by **Bensdexta** » Sat Jul 31, 2010 5:28 pm

dpalombaro wrote:I dont have a parts manual, the new pump is S.60443 to replace 957e9350b from yesterdays tractor.com. are there different pumps?

Parts List is downloadable from www.fordson-dexta.de
All the best

GERRY · Post by **GERRY** » Sat Jul 31, 2010 6:18 pm

If it is spitting diesel in spurts from injector lines it is working correctly, , mybe a little sray of starting fluid might get you going , but do not over do it a spray inthe air inlet and thats it as this stuff is leathal to dexta engines . but if it was starting easy before and did not need s/fluid it should not need in now, if possible it would be better to tow ,a car would do for this , GERRY

Post by **Brian** » Sat Jul 31, 2010 6:26 pm

The fuel should flow from the pipe coming from the tank, under its own pressure. If it is not flowing freely you have a blocked filter in the tank and no matter how you pump or use starting fluid you will not get her running.

if you have a good flow then diesel should pour out of the bleed screws and squirt about 5", when you operate the hand primer. It will not come out of the injector lines until you are cranking her over.

If you are cranking her over and getting clouds of white smoke from the exhaust, a shot of starting fluid may be used sparingly to get her to fire up, but only if she is pouring white smoke out of the exhaust.

dpalombaro · Post by **dpalombaro** » Sat Jul 31, 2010 8:22 pm

Brian wrote:The fuel should flow from the pipe coming from the tank, under its own pressure. If it is not flowing freely you have a blocked filter in the tank and no matter how you pump or use starting fluid you will not get her running.

if you have a good flow then diesel should pour out of the bleed screws and squirt about 5", when you operate the hand primer. It will not come out of the injector lines until you are cranking her over.

If you are cranking her over and getting clouds of white smoke from the exhaust, a shot of starting fluid may be used sparingly to get her to fire up, but only if she is pouring white smoke out of the exhaust.

fuel flows freely from tank. sometimes the primer does not do anything or feels that way. if i loosen the line from the pump to filter and crank it shoots out same loosening line to the injector pump seems to be adequate

barely spits out injector line but at least i am getting it up there now since replacing pump.
it does not pour smoke but puffs on every crank.

thank to all for the help i will keep trying ,something

Post by **Brian** » Sun Aug 01, 2010 12:04 pm

There are times when the primer will not work. That is because it has stopped on the top of the drive cam and cannot move any further. Just turning the engine a little will bring it back into operation.

Diesel will only spill out of the injection pipes. There is only a small amount metered to each pipe, even when the engine is flat out.

Think 2 gallons an hour through all three pipes, then break it down to the time you are turning the engine over and that will give you an idea of how much to expect. It will not be under any pressure as it needs the spring in the injector to build that up.

A small amount of starting fluid or a flame in the intake manifold should get you going again.