We have used the larger turbos on our water blaster. They seem to really come in to their own at 5,000 psi and above. They hold up Ok. We don't like them at lower pressures because they don't rotate as fast as the smaller uints.
I would do as B.E. Young Sr. suggests, get a smaller turbo and run it till it breaks and then replace or rebuild.
My $.0025 worth
Dave Olson
Tidy Powerwash Service, Inc. P.O. Box 781, Catlin, Illinois 61817 Phone 217-427-5557, Fax 217-427-2632 We are a commercial cleaning contractor serving East-Central Illinois and West Central Indiana since 1984.
http://www.tps-inc.com