I have a 2005 Holiday Rambler Endeavor with a Cummins 8,9 ISL 400hp with an Allison 6 speed transmission with 57,000 miles on it. I bought it new and have always performed the basic routine maintenance on it. Oil change, filters, coolant flush, etc. I have never had any trouble what so ever with drive train until this past trip. While Going up a small grade I heard a loud pop and lost almost all power. I looked down at the gauges and saw I had zero boost. After pulling off to the side of the road, I removed the inspection cover in the bedroom and saw that the clamp on the turbo hump hose had broke and the hump hose had blown off. These clamps and hoses arenโt stocked at your typical auto parts store and so I was left in areal jamb. After some Mcgyver work I was able to baby it to our destination where I inspected further only to find that 3 out of the 4 hoses were ready to fail. These are hump hoses with expansion rings on them. Two of the hoses only had one expansion ring left and one had two. The fourth hose still had all three rings. Needless to say, I replaced all 4 hoses. So my question is........those of you that have the Cummins 8.9 ISL motor, what have you experienced with this motor that I should be looking at? Iโm thinking it might be time to replace all the belts and hoses. Just trying to do some preventative maintenance to avoid being left on the side of the road again. And if you have this motor, I would suggest keeping an eye on these hoses and even carrying a couple of spare clamps and a hose too. Iโve attached a pic of one of the hoses I replaced. This one was missing one expansion ring and you can see how it was swelling where the expansion ring was missing.
So letโs here it, what should I be replacing on a 13 year old motor with 57k on it.
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