Hello! I have some problems with my MSD 5973 (diffusion pump). Nitrogen was between 10-18% and EMV between 2400-2600. I bought supplies and i did a maintanance: I changed He trap, MSD column Nut and ferrule, diffusion pump oil, filaments, interface, analyzer, PTFBA valve and vent valve o-rings. The first days, my EMV decreased to 2100,… Show more
Hi, Looks like you found the leak at the oring. Great job!!!. That's a typical place for a leak especially if you had the shipping screws tightened. I think replacing the EM is a good start. Try rotating your horn 90 degrees. Sometimes it will buy you some time and definitely point in the direction of the horn.