82 300TD SLS pump issues

[nicholas]

I've narrowed down my innoperable SLS system, I think, to the SLS pump.

I have been getting non-stop bubbles out of the bleeder port while trying to burp the system after rebuilding the valve and pump.

The pump itself appears to be the source of the bubbles - I disconnected the high pressure line from the pump and fed it directly into the reservoir. After starting the engine, the fluid flows steadily but is filled with small bubbles. I can see the bubbles clouding up in the reservoir as it is being refilled from the high pressure line. So does anyone have any experience with this? The simplest explanation seems that there is air being sucked in either from one of the connections on the suction/return line to the pump or from some seal in the pump itself. I did just rebuild the pump, so could it possibly be that one of the seals didn't align right, or is this a sign of a pump at the end of its life? Any insights ?