kaypsmith Report post Posted August 22, 2018 Here us a youtube video of replacing the fan hub on the 6.7 and 5.9 Cummings. Share this post Link to post Share on other sites
wolfe10 Report post Posted August 22, 2018 15 hours ago, thomandcoley said: Also I can see more than just the hole in the fan shroud from inside the bedroom floor - around it looks clean. Maybe I am looking at the radiator? I need to take pics. NO, you are not looking at the radiator from the bedroom. As has been mentioned several times you are looking at the FRONT of the CAC (Charge Air Cooler). The radiator is behind (toward back of the coach) the CAC. You chassis maker (If Freightliner, call Gaffney) is the one who can absolutely tell you what the correct (minimum) process is for replacing the fan hub. Share this post Link to post Share on other sites
wildebill308 Report post Posted August 22, 2018 What you need to do is to replace the fan clutch. I wouldn't do anything else right now. What you need to do is to replace the fan clutch. Anything else is added profit for the dealer. What you need to do is to replace the fan clutch. Bill Share this post Link to post Share on other sites
wildebill308 Report post Posted August 22, 2018 Kay, I believe he has one of the electric actuated clutches. The video is a good one on installing an adapter to replace the original fan clutch. Making it a full time direct drive, eliminating the clutch. Bill Share this post Link to post Share on other sites
kaypsmith Report post Posted August 22, 2018 15 hours ago, thomandcoley said: Latest update: Cummins in Salt Lake says it needs fan hub. Thanks Bill I agree, Cummings shop is telling him that it needs a fan hub. Were it mine I would only replace the fan clutch, and only after the CAC and radiator have been thoroughly cleaned and the problem still persists. I have a new fan clutch sitting on my desk that I will be replacing on the Jeep this weekend. I've seen more fan clutches go out over the years than I care to remember. On a Fred it is much easier to determine this, as you just drive faster to see if the coolant cools down with additional speed. Share this post Link to post Share on other sites
thomandcoley Report post Posted August 22, 2018 Hey all - Can't thank you enough for all the great info. After taking it to Cummins to be checked out, the super qualified technician there left off my radiator cap. Shortly after departing the place, my friend driving behind me called and alerted me to steam coming out of the back. So I had Cummins send their mobile tech out with more coolant. He put 7 gallons in it!!!!! This morning, we sprayed the CAC and radiator with Simple Green Extreme, some dirt came out but the water was mostly clean and clear after soaking it really good. Drilled a hole in the bottom to let it drain (will be plugging it up later today). My buddy said he could see light coming through the radiator once I started spraying the Simple Green. That did not solve the problem. We departed and maybe 10 minutes in, it was already overheating, not towing the car, on relatively flat ground. While on the side of the road waiting for it to stop overheating, the mobile tech from the previous day just happened to be passing by (how odd!) and stopped to assist. Hooked computer up to it, had me rev it up til it was 210 degrees. He couldn't over ride the fan with the computer to make it come on, tried a couple different things. He said the fan clutch is shot. At 210 degrees, the fan was just spinning freely. Also, he didn't charge me for his time. My friend suggested adding an extra cooling fan as he has one on his hot rod. We mounted it on the radiator in the back. That did not solve the problem. We have the fan clutch ordered, arriving tomorrow. We made it to Spanish Fork, UT and the mechanic here said he can get the part in the morning (which by the way is $300 less than the one from Cummins, even though coming from same place!) Also his hourly rate is about half of what Cummins rate is. He says he can try to replace it without removing radiator and CAC. Hoping this FINALLY solves the problem! Share this post Link to post Share on other sites
thomandcoley Report post Posted August 23, 2018 The FINAL update! Again, thanks for sharing all of your vast knowledge, you all are the best! FINAL VERDICT: Fan clutch. $650 part A guy named Don at Spanish Fork Diesel Repair in Spanish Fork, UT got us in quick and the final bill was $989 versus $6800 at Cummins. Who, by the way, was gonna charge us $952 for the part. Grrrrr. They said they would HAVE to remove the radiator and all to fix it. Not so. Don fixed it from the access hole under the bed. We are heading to Creede CO now to headline the Headwaters Music Festival Saturday and Sunday. We made it over the mountain passes towing a car and the hottest it got was maybe 212. At 210 we heard that big ol' fan motor kick in and it dropped the temp right away. Share this post Link to post Share on other sites
thomandcoley Report post Posted August 23, 2018 On 8/22/2018 at 10:53 AM, WILDEBILL308 said: What you need to do is to replace the fan clutch. I wouldn't do anything else right now. What you need to do is to replace the fan clutch. Anything else is added profit for the dealer. What you need to do is to replace the fan clutch. Bill Got it! SPOT ON! Don't have to tell me a 4th time! Share this post Link to post Share on other sites
wildebill308 Report post Posted August 24, 2018 2 hours ago, thomandcoley said: Got it! SPOT ON! Don't have to tell me a 4th time! Share this post Link to post Share on other sites
richard5933 Report post Posted August 24, 2018 10 hours ago, thomandcoley said: They said they would HAVE to remove the radiator and all to fix it. Not so. Don fixed it from the access hole under the bed. Some shops will not do anything that requires them to work from inside a motor home, so there's a good chance they saw removing the radiator as the only route to the repair site. Not saying I agree with their approach (pun intended) but I do understand the reluctance of shops to send a grease-covered mechanic to work from inside a motor home that costs as much as some do nowadays. Especially if their bread-and-butter is working on commercial vehicles. Only takes one or two expensive carpet or upholstery damage claims to scare a shop from working through the hatch in the bedroom floor. Glad you got it resolved. Sometimes a motor home owners best tool is perseverance and determination. Share this post Link to post Share on other sites
jleamont Report post Posted August 24, 2018 Glad to hear! Share this post Link to post Share on other sites
obedb Report post Posted August 24, 2018 The fan clutch was the suspect by several of us. Glad that you finally found a fix. What an experience for you folks. Share this post Link to post Share on other sites
desertdeals69 Report post Posted August 24, 2018 My 98 ISB has a solid mount fan so I don't have to worry if its working or not. I think they started putting clutches on when there were complaints that the fan made noise like a B29 going down the runway to take off. Share this post Link to post Share on other sites
jleamont Report post Posted August 25, 2018 DD, I believe they came along with the electric clutch technology, now we also have water pumps with clutches to speed them up and slow them down for MPG Share this post Link to post Share on other sites
obedb Report post Posted August 25, 2018 In most of my 18 wheelers, I had an on/off toggle switch to over ride the sensor. When starting up a steep grade on a hot day, I turned the fan on early. I have known big fleet tractors to shutoff on a steep grade on a hot day. The temp rose so rapidly, that when the fan kicked on, it was too late to recover the cooling system before shutoff point. Have seen it many time in deserts out west on summer days. Sometimes well over 110 degrees. Guess the big fleets did not think that the driver was smart enough to handle something as complicated as an on/off switch. Also used it when Idling with the A/C on. I remember temps as hot as 121 degrees. OK! Maybe only 120.😎 Share this post Link to post Share on other sites
