Losing power steering fluid through lid

[First Pooy]

Ok on my 92 Gq S2 Td42 I have a Gu PP it was on there when I brought it and you could tell it was brand new, I first had trouble with it when I parked on a hill ober night it would drain back some how and I would have no power steering until it bleed up again, I gave it a heavy bleed and thought the problem was fixed well it lasted a few days and it did it again so I stoped parking on hills so over time it stopped doing it some were but is had a leak that I said I would track down some day, well I toped up the PF before a 1000 km trip well approximately 500 km into the trip in the middle of no where I checked my PF and it was down to minimum and thanks to all the dust I could see it was coming up from the cap and mybe the seem at the top of the reservoir, well I had to leave the group and do an emergency drive to the nearest town to buy some PF so I thought mybe the pully was the wrong size but apparently the Gq and Gu are the same so it has got me stumped a prity new pump is some how over presserizing

[mudski]

So its leaking fluid via the cap on the reservoir? Is the cap missing the seal under the lid?

[First Pooy]

So its leaking fluid via the cap on the reservoir? Is the cap missing the seal under the lid?

No the seal seems fine and to my knowledge it is new with the pump

[mudski]

When you say drain back. Drain back to where?

[First Pooy]

When you say drain back. Drain back to where?

I don't know where but I would have to drive down the road for 10 or so meters before I got power steering back so in my opinion it bleed back up

[mudski]

I don't know where but I would have to drive down the road for 10 or so meters before I got power steering back so in my opinion it bleed back up

Yeah Im a bit lost here sorry. It shouldnt have to bleed back up. The Power steering system should be full with no air. So is it leaking whilst stationary or whilst on the move? And its only leaking from the cap? There is absolutely no wet spots on the pump, behind the pulley, or the hoses and fittings or on the box? All hose fittings are 100% tight?

[mudnut]

Hasn't got too small a hose fitted any where? A kink in a hose or a blocked strainer?