The Fordson Tractor Pages Forum

Hello,

Can I exchange a SPE4A70 pump, used on the early type Majors by a SPE4A75 one, used on the later type Super Majors?
According to the I&T manual not, but I don’t see way not.
I have a spare one and want to test it on the major.
I know there’s a topic about this but cant find it.

You must give the full SPE number.

You do not have an early Major Henk, there were two pump changes before your version.

There will be no problems with fitting the pump, it will be settings that may be slightly out. In service we interchanged pumps without problems as long as it was on the later tractors. The pump should be inclined not the verticle one or the one with only four bolts on the cover plate.

Thanks,

The differents is the size of the plunger. The old one is 7 mm and the later version 7.5 mm.

I have installed the rebuild pump last week and it runs well. The strange behave of the rev was a bit less.
Whit my pump, Idle 550 to 600. Going up to 1100 rev, than going down to 850 and than going up to full.
I am now repositioning the forks on the fuel rod.
It should start 4 mm from the square front. Mine starts 2.5 mm and the rebuild pump on 3 mm.
I have measured the distance between the forks and start it on 4 mm. Than put the pump on the tractor and see what is does.

Henk,
Where did you get the 4mm specification? Why are you setting different from your rebuilt pump?

After you move those forks, each plunger will be pumping a different amount of fuel instead of all of them pumping the same amount, like they should. It will probably be OK to put it on your Major to see if it runs, but don't do any work with it (including driving it) until you have it calibrated by a fuel injection shop.

Hi Henk
It sounds to me like the damping in the pneumatic govenor is messing around to give the surge problem and that needs looking at.

Like JC said the calibration to the pump is now out of line. if you scribed marks on the shaft before you started moving things or have exact measurements you may be able to get the calibration back. if not you will have problems with un even fuel delivery to each cylinder and risk snapping the crank on what ever motor this pump gets fitted to.

this would be due to the un even fuel burn in each cylinder giving more power to certain cylinders and things not being even.

The other thing could be she will burn pistons with to much fuel in the cylinder.
I have just looked at a 2100 Leyland Tractor that ran with the excess fuel jammed on for a year or 2 .
she has burnt right down the side of the piston and you can see down from the top and see the top ring in its groove without taking the pistons out .

I hope you can get the thing back ok as this is a kind of expensive mistake having to get the pump re calibrated. Most pump guys want pure gold for there shop time these days .
Having said that it is also not cheap to destroy a motor with a bad pump so it may be worth getting it re set properly anyway .
good luck
Regards Robert

JC,

The 4 mm is the setting according to the I&T shop service book.

I have mark the forks and measured the distance accurate in different ways, so I must be able to place them back in the new as the old position.
I just want to see what it does.
I bought this extra pump cheap to use it as a learning object.

Robert,

You could be right, but I have tried different positions with the damping valve, and no result. I’m using the pump to see whether its the pump or the vacuum.
I have changed nothing on my pump on the major.

My plan is to make a testing machine myself to calibrate the opening point and the calibration of the fuel gift. But that’s for the future.

Thank you for all the input you give, its welcome and I’m learning from it.

This is why I had to remove the fuel rod.

Hi Henk
I have the I&T manual no FO 21(not the new one that covers major and ford tw ) I seem to be lost on the 4mm that you talk about where are you finding it. as my book says basically apart from govenor settings and swapping old and new style damping cones and pipes to stop sergeing. it' s leave the rest alone its diesel shop only .
Regards Robert

I&T are worse than useless.

There is no way to set the pump other than with a Hartridge or similar test unit. There is a time factor and revs for setting, fuel delivery from each plunger is critical. It is not just spill timing or amount. It is delivery at a range of rev settings too.

If there was a way around using such equipment then most shops would be saving the cost of having the job done at diesel shops.

Wrong settings can be very expensive on engines too.

Robbert,

My I&T is FO12. page 29.
Cold you scan and mail the page about the damping valve?
Cause that could be an item on the both two pumps.

Brian,
I know it has also to do with the amount of fuel at a number of rev.

The second hand pump has to be set, and need some new parts. Than it would be useful. So in the mean time I can do some experience with it.
As I say before, I wont change anything on my one pump.

Thank you all for the warning and concern.

Made a new repair page (5) on my site about the pump rebuild.
http://people.zeelandnet.nl/hmdetroije/

Eureka,

I found out what causes the strange behaviour from the throttle.
Last Saturday I visited a part seller who lives about an halve hour diving from me with Pascal. The parts Pascal needed came from an engine just like mine. It had two large diameter vacuum pipes on it. I have bought them and put them on the Major yesterday.
The problem was gone. Seems that a previous restores has made some pipes himself but did not do a good job.

Now only the minimum rev at idling is to low. I had to adjust it with the butterfly in the inlet. Is this all right or should it run about 550 to 600 rev with the butterfly nearly closed?

Sometimes it is the simple and obvious things that get over looked in a job. I can see where the tube diameter would make a difference. Sometimes it is difficult to trace someones shoddy workmanship from the past. Bravo on finding the problem! Dandy Dave!

Hello Henk,

Glad you found the problem.

Regards

Emiel