I have 2008K machine that passes the alarm test and PHT but fails diasafe test. Replaced diasafe plus filter still fails, replaced vent filter and it still fails and I replaced the diasafe holder assembly and it still fails. Here is what I am seeing when test runs. Uf pump will stroke up to 160 tmp will not go above 20 and I see lots of air in dialysate lines during test. I have also replaced test valve on diasafe plus assembly. Any ideas. Thanks

Try positive/negative pressure procedures.

Tried positive/negative pressure procedures no leaks detected. Ugh

You mentioned UF pump ramped-up to 160 TMP, however "will not go above 20", what will not go above 20?
If TMP will not go above 20, then you may have a broken spring within the UF pump, or the o-ring at the in-line filter (hose from bottom of dear chamber to UF pump) is not seated correctly (comman after an annual PM. Or the wiring harness on the top of the dear chamber (blue/brown connactions)could be shot at one or both ends (it connects to the distribtion Bd, and have seen broken connections).

The problem ended up being the diasafe filter. I had 2 diasafe plus filters from the same case bad. this was a pain in the butt. after replacing it for the 3rd time it passed. thanks fresenius

Just an idea, although adding a few more minutes to your day. Borrowing a used (good) filter from another machine will clue you in to bad batches. Man made and echo en Mexico can get you pulling your hair sometimes.