Tuff Torq K71 Gearbox Oil Fill Level Problem?

[WestyFan]

Hi everyone,

I have a British made Countax diesel D18/50 fitted with a hydrostatic Tuff Torq K71 transmission. It also has power steering which runs from the gearbox. I have changed the oil however I haven't put the amount in which is suggested in the manual. It states it should have 4.0 litres of 10w40 oil however I have only managed to put 3 litres in. The oil was overflowing out of the filler cap so I started the engine and got the oil circulating through the power steering. I have rechecked the oil and it has gone down a small amount. There is no oil in the reservoir which sits above the transmission so I am unsure of what to do because surely if I put more oil in the resevoir it will overflow out the lower filler cap? I really don't want to over fill it and blow a seal. Please can someone shed some light on this situation as I have been left scratching my head. Also just for arguments sake I did fully empty the original oil from the unit, it was totally empty before I filled it up with new oil.

Thanks in advance,
George.

Here is the manual I was using http://static.fatsoma.com/gts-pdfs/service-bulletins/gearbox-oils-and-bleeding.pdf

 

[mechanic mark]

https://www.tufftorqservices.com/EnvEEdefault/FlatHTML/TechInfo/docs/Manuals.htm

 

[pugaltitude]

K71 has 2 fill points.
One is through the yellow fill plug where the diff is.
The 2nd is through the reservoir.
Remove the reservoir by undoing the 12mm bolt on top of the transmission which is in front of the reservoir.
The 12mm is connected to a pipe which goes in the gearbox.
remove and with a pipe fill up the level until it is topped up.
Then fit the reservoir and fill up. While filling oil engage hand brake and turn white fan on gearbox.
Fill up diff side.
Now you need to purge air.
Jack rear wheels. Add weight to seat switch. Start engine at low idle with dump valve pulled out. Disengage handbrake to allow gearbox pulley to turn. Push and pull forward pedal then push dump valve
In and push pull forward pedal and keep repeating until wheels move.
Increase rpm and that should be it.
Turn steering couple times for power steering.
Use a 5 or 10/50 fully synthetic oil for long life instead of a 10w40.