Caterpillar C9 engine owners may want to check into this. On Monday, as we were preparing to leave, I went to check the oil and had trouble removing the dipstick. Even worse, I couldn't get it back into the tube. After a lot of research I learned that the tube is not metal, as it appears. It is a flexible composite material that doesn't have a lot of heat resistance and will melt if it is routed too close to the turbo. Spartan Chassis discovered this in 2005 and issued Campaign Service Bulletin CSB05-170-001 announcing the availability of a kit designed to address the problem. The kit is basically a new dipstick tube that is encased in a heat resistant length of loom. I went to Cashman Equipment, the Cat shop, in Sparks, NV and had them order a new tube, showed them Spartan's CSB and they got us in the shop and back on the road before 10 Tuesday morning. On our coach I couldn't see where the tube had melted, but I was able to reach down in there and I could feel the melted part of the tube and how close it was to the turbo. Anyone with a C9 may want to check this out and apply the appropriate fix.
http://www.spartanchassis.com/cps/login/UploadedFiles/CSB05-170-001%2005007%20MH352%20MH442%20Dipstick%20(Rel%207-1-05)_12820061611078842500.pdf
