DB 780 Selectatic Trans Oil Filter Problem

[DrWazzock]

Tractor is in a Standen solo beet and in annual use harvesting the fodder beet here.

Every year the filter suction warning light comes on and every year I have to change the transmission oil and the filter and clean the bypass strainer gauze.

I replaced the gear lever boots to stop water getting in a few years ago and each time I change the oil there appears to be less and less water contamination but even so, having to change the filter when only doing maybe 50 hours a year seems a bit excessive. The machine is never left out in the rain.

I am using 15w 30 universal tractor oil. It's a vapormatic paper element filter. Am I doing something wrong?

 

[Exfarmer]

Is this the yellow light on the dash.
If so seem to think it was normal for this to show for at least 15 minutes after startup. Confused many people and I am not sure why DB ever included it.
May be totally wrong , but if there is no water in the transmission i would think nothing is wrong.
May be worth posting on the DBTC forum or perhaps @John 1594 would likke to comment

 

[John 1594]

Yellow light can take up to 30 mins to go off in cold weather, especially if the tractor is being used at high revs with the oil flow in constant pump

What does the element look like when its removed? Is it all slimy and gunged up from contamination or is it always clean?

The light was really meant to indicate when the bypass valve in the filter was open and the oil was flowing round without going through the filter. Be aware that the orange hyd light is linked by a diode to the charging lamp, so any faults with the charging system which put the charging light on will also put the hydraulic light on!!!

It could be a faulty vaccum switch, they do fail over time. New ones are adjustable, so you can set them up to suit the tractor. Basically you fit a new filter and new oil, get the tractor up to working temperature, then run at full engine rpm whilst adjusting the cut off point of the vaccum switch, so the light will just stay out. When oil is cold and high revs it will come on occasionally until the oil is warm, which is how it was meant to work

If there is shite left in the gearbox from old oil, drain oil again, leave old filter in, put 5 gallons of diesel in the gearbox and let the tractor idle for a few minutes to swill it round...its suprising what extra rubbish comes out

 

[DrWazzock]

Thanks for the comprehensive advice.

Old filter was partially collapsed and bottom suction bypass mesh was clogged with fine dirt and gunge. Cleaned the mesh with petrol. Left gearbox to drain a good while when it was hot and looks clean and emulsion free inside now.

I have installed a new filter and refilled with clean oil. Light not on now.

Getting the filter to fit was difficult. Should be a push fit I think up into the suction inlet of the pump, but the O ring kept on rolling out of its groove rather than compressing into its groove. Seemed like the tube on the filter was slightly smaller and the o ring slightly bigger than the old one which didn't help. Work of the devil. Eventually wound some insulating tape round the filter tube next to O ring to provide some backing for the o ring to stop it rolling out of its groove. Seemed to do the trick. Even if the tape comes off it shouldn't go anywhere.

Will see how long it goes before it needs another, but the oil does look drier and cleaner every time it's changed so maybe it will last longer now before clogging filter. As usual a legacy from previous owners neglect.