I have a 1967 4020. It has a JD dealer rebuilt engine with 700 hours on it. it has always registered low oil pressure. I decided to buy an oil test gauge to determine if it was actually low pressure or a gauge issue. After connecting the oil pressure test gauge, started the engine and it registered at 30 PSI. I then operated the tractor for about 20 minutes to bring the engine to operating temperature and as the engine was warming up at 1900 RPMs, it gradually dropped from 30 PSI to 18 PSI - and would drop to about 10 psi at 500 idle RPMs. The shop manual says that at 1900 RPMs, the pressure should be at 30 PSI. If it isn't, the manual suggests adjusting the pressure valve/screw.
I tried to adjust the pressure by screwing both in and out the adjustment screw that sits just behind the oil fill cap on the right side of the tractor - pressure did not change at all - just remained the same whether screwing in or our.
Someone told me that the pressure drop might be coming from bad oil pipe O-rings - maybe even bad oil pipes.
So, I thought I would check to see if anyone might know specifically the issue. if this is it, I've got a little work ahead of me to replace the O-rings/tubes, but if not, I've got some more searching to do.
Any help would be appreciated.
Rick
I tried to adjust the pressure by screwing both in and out the adjustment screw that sits just behind the oil fill cap on the right side of the tractor - pressure did not change at all - just remained the same whether screwing in or our.
Someone told me that the pressure drop might be coming from bad oil pipe O-rings - maybe even bad oil pipes.
So, I thought I would check to see if anyone might know specifically the issue. if this is it, I've got a little work ahead of me to replace the O-rings/tubes, but if not, I've got some more searching to do.
Any help would be appreciated.
Rick