Fuel pipe from primer to inlet manifold?

Dextrous · Post by **Dextrous** » Tue Aug 11, 2009 5:42 pm

Hi

I'm just dismantling my 1964 Super Dexta and I have a pipe missing. However when I come to replace it I'm a bit confused where it goes, I've looked in the parts manual and its a bit vague.

The primer tap underneath the tank had been butchered, probably because the primer bulb leaked. Its not a tap or a primer anymore - I've splashed out an bought a replacement. There is a pipe from here feeding the injector pump, and there is the return pipe from the injector pump direct to the tank.

There is no pipe from the inlet manifold for priming on my tractor, however when I come to replace it, I'm not sure where the other end goes as the tap/primer underneath the tank has only one outlet and this is used to feed the injection pump. Am I being dense or is something missing?

Regards
Andy

Post by **Brian** » Tue Aug 11, 2009 10:57 pm

There should not be a return to tank from the pump. The injector leakoff returns to tank and the pump return should go to the fuel filter.

The primer line goes out from the fuel tap/primer at right angles from the main fuel line to the filter.

So your lines from the tap should be: 1 to Filter, 1 to Manifold, from the filter you should have two pipes both going to the injection pump and from the inectors 1 line going to tank.

RossM · Post by **RossM** » Wed Aug 12, 2009 7:31 am

Dextrous, your post is of interest as I recently saw a Super Dexta at a show that had no pipe from the primer to the manifold. Mine has the Pipe and primer pump (and have just bought a new primer) but when talking to the owner of the one at the show he said it was not needed as the super dextas had the excess fuel buttons on the fuel pump.

Interesting.

Dextrous · Post by **Dextrous** » Wed Aug 12, 2009 8:01 am

Many thanks for your replies.

I did omit the filter - the feed pipe does go the pump via the filter and I did mean the injector leak-off returns to the tank - not very well explained by me - I'll try and be more exact next time!

I'm working away for a couple of days so I haven't got the primer tap in front of me however from here's a picture from Stefan's site http://www.fordson-dexta.de/images/hahn29.jpg.

It has two connections - one that fits into the base of the fuel tank and one outlet. How do I connect the pipe to the fuel filter and the pipe from the inlet manifold to this single outlet?

A picture of your set up Ross would be useful if it shows how this is done. Maybe mine never had the pipe?

Andy

Post by **Brian** » Wed Aug 12, 2009 9:12 am

That is the problem when people do restorations and don't know their subject.

ALL Super Dextas came with primers, the excess fuel device on the pump does not help fire the diesel, it just puts more fuel in. Works well with a direct injection engine but not with an indirect like the Dexta. You need the fire in the manifold being drawn into the cylinders.

If you have a primer tap, you must have a third outlet although I have not seen your tap.

Is it possible that your primer in your tap just pressurises the main fuel line and it does not operate like a Dexta should?

RossM · Post by **RossM** » Wed Aug 12, 2009 9:57 am

Unfortunately Dextrous I don't have my tractor at home at the moment to take a picture. Your primer pump should have the inlet on top from the tank, outlet to the left going to the fuel filter and then an outlet out of the back to go to the mainfold. The pipe from the primer to the manifold should run under the tank and then up the right hand side of the engine into the tap on the Air Inlet Manifold above the heater plug.

Dextrous · Post by **Dextrous** » Wed Aug 12, 2009 10:39 am

That should do it - I now know where the pipe should route.

I'll take another look at the tap when I get home on Thursday as it is similar to Stefan's as it does show a third orifice at the bottom of this picture of his tap - it's bolted to his work stand via the outlet to the filter.

.

So either I've had a senior moment and missed it or my tap is wrong. I obtained the tap a couple of years ago when I was under the illusion that I could work on the tractor outside in the Pennines so it may be expensive junk.

Regards
Andy

Post by **Brian** » Thu Aug 13, 2009 8:02 am

That does not look like a standard Dexta fuel tap. It is possible different countries used different parts.

Dextrous · Post by **Dextrous** » Fri Aug 14, 2009 8:21 am

The new tap is OK - there is a third hole - phew! The hole on the old tap had been filled in with some kind of sealer and the layer of dirt had hidden it.

At least I know that the manifold pipe should be there and where it is routed.

Thanks
Andy

Bensdexta · Post by **Bensdexta** » Fri Aug 21, 2009 12:35 pm

Brian wrote:That does not look like a standard Dexta fuel tap. It is possible different countries used different parts.

The pic is of Stefan's modified tap/primer. The main casting is original (actually it is marked 'bpc ' - is that Bepco?), but he has bolted on a new primer body with a Stihl primer bulb to replace the original primer button/plunger. The Stihl bulb, nipples & hose cost <£10. The bulb has built-in valves, which does away with the original rubber flap valves, which on mine have perished.
It's an ingenious solution - has anyone else besides Stefan made one?

What are people's experience with the after market primers from the likes of Sparex, Agriline etc? Do they leak?
All the best,
Ben

The Fordson Tractor Pages Forum

Fuel pipe from primer to inlet manifold?

Fuel pipe from primer to inlet manifold?

Stefan's fuel primer mod