D4 6u Hyd control unit

The original spec was motor oil same as the engine. Today I think I would use a tractor hydraulic fluid like hytran or "303" fluid. Should offer better performance and is usually cheaper to boot.

The pump in the unit is a vane type, first thing is to change fluid and filter. There war two different filters used depending on model and serial number. One is the same as a fuel filter and readily available, but the other more common one is a cartridge that is usually only available from CAT and is quite expensive.

Thecserial number of the unit is almost always on the rear face of the tank (next to radiator) just below the filler spout. Usually have to scrape away the accumulated asphalt-like accumulation of dust and oil to see it. With a serial number someone can give you more information specific to your unit.

Thanks I'll have a look for that number

Hi the number is v7536 that I can see

Ordered some of those filters today. The parts guy mentioned that the number had changed from 2A-5886 which is the individual filter vs the parts book number listing a set for each tractor's fuel system. . Until they show up tomorrow i won't know what the most recent number is. The CAT parts order system will sub up to the most recent number automatically. The filters were about $15 each.

So I changed the filter it does work faster that it did but now it is not lifting the blade at all and sounds like a relief value is possible open can I'd be fixed