The Fordson Tractor Pages Forum

on my SM theres a small dipstick beside the gearstick can anyone tell me what this is for?

Rear transmission.

The front transmission or gearbox is in front of that dipstick. It is a big flanged nut with oil level marks inside

Cheers i was wondering so how do you top up the back end?

Got it topped up but the back arms go down very quick then sitting they used to stay up over night now they go down after a hour or so

Non of the hydraulic systems on Fordson tractors are meant to hold up for long periods. This has been a bone of contention between Ford and Fergusson over many years. A plough on the back of a Fergusson hits the ground before you leave the seat and that is OK, its a safety feature (??) but if a Fordson tractor drops the same plough in a week, then there is a hydraulics problem.

The most likely cause is a piston seal but just carry out this check, when loaded, raise the weight on the arms to the top and pull out the auxiliary service knob. Then with the engine stopped see how long it takes to drop.

If it still drops your problem is piston seal, scored cylinder or ram cylinder safety valve. Could also be "O" rings on the aux. service chest or ram cylinder.

If it stays up your problem is control valve leaking or unload valve plug leaking or possibly check valve.

But do not expect the lift to hold for long periods without dropping.

Brian wrote:Non of the hydraulic systems on Fordson tractors are meant to hold up for long periods. This has been a bone of contention between Ford and Fergusson over many years. A plough on the back of a Fergusson hits the ground before you leave the seat and that is OK, its a safety feature (??) but if a Fordson tractor drops the same plough in a week, then there is a hydraulics problem.

The most likely cause is a piston seal but just carry out this check, when loaded, raise the weight on the arms to the top and pull out the auxiliary service knob. Then with the engine stopped see how long it takes to drop.

If it still drops your problem is piston seal, scored cylinder or ram cylinder safety valve. Could also be "O" rings on the aux. service chest or ram cylinder.

If it stays up your problem is control valve leaking or unload valve plug leaking or possibly check valve.

But do not expect the lift to hold for long periods without dropping.

Hi Brian Nice to see ya back after your Travels . Unless hes Changed the hydraulic top on the Tractor for the correct one It had the old style power major top Fitted. He doesn`t have the external services knob .
Regards Robert

Hi thanks for the reply what or where is the auxiliary service knob ?

From what Robert says you do not have a Super Major hydraulic system. It would be a good idea to tell us this when asking a question.

With the old Power Major system you can still have a faulty piston seal or a faulty "O" ring on the cylinder or even score marks down the cylinder which can give you problems, Also the unload valve can leak. This is really the safety valve of the lift and will blow off the seat if a heavy load is lifted. You can hear it leave the seat with a loud "click" and the lift stops lifting.

This valve was the weak part of the lift design and was the subject of three changes in the design of the valve. Unfortunately they are not really interchangeable without changing the whole valve chest for a later model.

Over the years, use will cause wear on the seat and the valve and this will cause the lift to drop. The latest design used a ball on the seat instead of the needle like original design.

My first area to check would be the piston seal, this is an odd size, when I changed mine, the local seal company had it made specially and it cost me £11.00, They made it of a nylon type material that they said would last another 50 years.