I recently bought a Massey 550 and noticed while sitting on the seat a lever to the left towards the floor with the words ext 1 and ext 2 on it.
The lever is in
between these to settings. Could you please shine any light on what this lever is for?
Also would it be hard to add a second spool valve to the tractor so i could tip the trailer without the hydraulics going up or down.
The lever is a 3 way valve. When it is in the middle position the rear linkage will work using the square and round levers.
Both the 1 and 2 positions are for external hydraulic services. One of the services has a single outlet and the other has a double outlet. One of the external
outlets is independent of the lift, so if you put the 3 way valve to one of the positions it will lock the arms where they are and only works the external hydraulics (eg. a tipping trailer), to operate the trailer you would use the constant pumping and down positions on the square lever (with the round lever in the fully up position). The other external service always lifts the linkage arms to the top and holds them there before lifting the external service (for example front end loader), on lowering the loader the rear linkage arms will remain in the raised position – this is extremely useful for using a counterbalance weight on the back of the tractor when using a front loader.
You say a second spool valve, does this mean that you already have one spool valve? On a 550 there isn’t normally a second hydraulic pump to power the spool valves, therefore it is necessary to shift the ext lever to the correct position and then put the square lever to constant pumping so that the spool valve is supplied with oil. If the tractor has the original type (Kontack) spool valve then it is possible to simply add another valve slice
using longer bolts.
Hope that helps,