Hi all We had purchased 10 RV pumps when they came out in 1994 at the Faculty of Sciences here at Ottawa U. In my lab I purchased 4 of them to replace the aging E2M5s on the stable isotope mass specs. The pumps were received with Edwards SuperGrade "A" Oil. The Oil broke down within one to two months to an almost water state. The sight glass became brown and needed to be removed and cleaned. The shaft seals started leaking on one RV8 and it was sent for warranty repair. The RV8 pump was returned and started leaking within two months. Contact with our sales rep at the time indicated that the Grade "A" oil was insufficient for these pumps because of the higher temperature that they ran at. We kept operating until the problem was sorted out. We changed all shaft seals and got some Ultra Grade 19 oilwhich was recommended. This solved the oil breakdown but not the shaft seal problem. Has anyone else out there had problems with these "new" pumps.?? Out of the four (two RV5s and 2 RV8s) one each are useless. The shaft seals on all of them were changed 4 times except for the one RV8 where it was done 6 times. The RV8 ran long enough to be out of warranty, as did the others.. The two others worked after Edwards sent some shaft seals with a spacer to move the seal down the shaft a bit. However this is still a 50% failure rate. I know that two other colleagues have had the same problem with more recent ones. Gilles Gilles St-Jean Technologue de Recherche U d'Ottawa/ Géologie/ Laboratoire d'Isotope G.G. Hatch 140 Louis Pasteur, Ottawa, Ontario, Canada, K1N 6N5 Bureau/Office: 1-(613) 562-5800 ext. 6839 Lab: ext. 6836 Courier-E / E-Mail: [log in to unmask]