I got a 97 t100 with dana 44 sas i also have power assist recently my pump started to make noise when i checked the fluid it was full. After driving for a while the pump started to make a lot of noise and i noticed when i turn off the engine power steering starts to leak out the cap. I also noticed foam. However when the engine runs it sucks all the fluid down and it no longer leaks from the cap. Im thinking bad pump? any ideas will help thanks in advance

 

foam is usually a sign of air in the system. Or it could be contaminated with water or something else. Are you using dextron atf? or off the shelf power steering fluid. Toyota system calls for ATF. Can you describe the noise? or possibly take a recording of it? The pump will moan under load but should not moan when you're sitting still.

 

the moan sounds like a typical power steering whine. Happens a lot when its cold. i had atf in there in the first place but than noticed it was overfilled so i sucked some out from the res. and put lucas ps oil. Drove fine for a day than lost steering did not have atf on hand so i used napa ps oil. Have steering back but pump is noisy and when i turn off the engine starts to leak out the cap like its overfilled again. Once the engine is started it sucks the oil back down

 

Sorry for the long reply but i ended up replacing the p/s pump and bleeding the system. Replacing the pump fixed the problem