PS pump or sector problem?

[71tahoe]

I've had this truck for a few months but haven't driven it much. Found a massive oil leak-fixed. Excessive blow by-not fixed. Weak battery-fixed. Soft brakes-working on it but that's a longer story. And there's the problem with the power steering.

It's leaking from the sector where the steering shaft comes in so that's obvious but the pump sounds like it's low on fluid although it's full. I filled it once because it was a little low, turned lock to lock several times but didn't help. This past weekend I pulled it around to work on the brakes and fluid spewed from the reservior cap. First time that has happened in the 150 miles I've driven it. What would cause pressure to build in the PS res?

[mclairmo]

Sounds like maybe you're sucking in air through that leak in the gear box (which might aerate the fuild and cause it to spew) and also losing fluid there. I would replace that gear box with a rebuilt unit, bleed any air and see if that stops the problems. If not, replace that pump.