U300 Raideator Fan

Topic: U300 Raideator Fan (Read 488 times) previous topic - next topic

U300 Raideator Fan

July 10, 2015, 03:13:12 pm

Hey Guys quick question. On the Unihome Coaches does the fan free wheel when u are shut down. I came back from Miles City this morning and had trouble with temps, was traveling on cruse @ 66 mph all was good until I hit a few grades and the temps got up to 210 at the summit. They went down once I started my decent , but wanted to stay around 195 the rest of the trip. outside temps were in the low 80's. When I got home popped the hood and took a look around all was good, coolant was good and I spun the fan by hand and I wondered if it was supposed to do that ?. Thanks for any thoughts, Andy

Re: U300 Raideator Fan

Reply #1 – July 10, 2015, 05:34:34 pm

Yes, the fans freewheel when the engine is not running and not pumping hydraulic fluid through the hydraulic motors. If temps go over 200 and climbing hills, it is a good idea to slow down, downshift to raise the RPM. There was a recent discussion on this.
Operating Temp

Good luck,

Re: U300 Raideator Fan

Reply #2 – July 10, 2015, 05:49:52 pm

Andy,

As Rick says, the fan should turn easily by hand when big engine is shut down. There may be some resistance felt, because you are turning the fan motor against the oil inside. Our coach has 2 hydraulic fans. If I turn one fan by hand, the other fan (connected only by a hydraulic hose) also turns at the same speed...COOL!

Re: U300 Raideator Fan

Reply #3 – July 10, 2015, 06:15:54 pm

Thanks Rick and Chuck, I am sure it's operating error on my part. My fan doses turn free. Thanks again

Re: U300 Raideator Fan

Reply #4 – July 10, 2015, 11:03:25 pm

Quote from: Andy 2 – July 10, 2015, 06:15:54 pm

Thanks Rick and Chuck, I am sure it's operating error on my part. My fan doses turn free. Thanks again

You have a rear radiator do you not?

Re: U300 Raideator Fan

Reply #5 – July 11, 2015, 09:41:06 am

No Bob it's a side radiator,coolant is fresh.Not sure when it was changed last either.

Re: U300 Raideator Fan

Reply #6 – July 11, 2015, 10:21:28 am

Andy,

Please confirm what coolant you used-- we have some members new to diesel engines and want to reinforce the need to use a proper coolant.

Thanks.

Re: U300 Raideator Fan

Reply #7 – July 11, 2015, 10:59:37 am

Andy,

Be sure to check fan speed. It's the best indicator that your hydraulic system is working correctly. If you have slow fan speed you have a hydraulic problem that needs some troubleshooting.

From my experience it's normal for the 6v92 to heat up during climbs. I spend most of my time out West so I'm always climbing! Long climbs are the bane of the 6v92 Foretravels. When Foretravel bumped the horsepower from 300 to 350 (in 1992) it didn't bump the radiator size enough to deal with the extra heat IMHO. So what Rick says about driving with the temp gauge instead of the speedometer on the hills is right on. The easiest and cheapest fix for this is to just slow down, change to the right lane, and put your flashers on.

The other issue is that once it's gets hot it takes a while to cool down. The problems is that the radiator also cools the automatic transmission oil. So in effect when the engine gets hot it heats up the transmission oil (or doesn't effectively cool it anymore). When you get to a downhill and the engine starts to cool it also has to cool the engine and the 10 gallons of ATF. As any bicyclist will tell you the downhills go by way quicker than the uphills! So watch your transmission temperature along with your engine temp.

Higher rpms help the engine cool by raising the fan rpm, pumping more oil, coolant, and fuel through the engine. The fuel is also what cools the cylinder heads. After a day on the road check the temperature of your fuel you might be surprised at how hot it is. The simplest approach to keeping the fuel cool(er) is to refuel when the fuel level gets to half a tank. I've just about decided to add a fuel cooler to mine. I'm waiting on Kent Speers to blaze the trail on this before I go forward.

Heat removed from the fuel is heat removed from the engine. I talked to Bernd about fuel temperature and he says the biggest issue is that when the fuel heats up it loses it's lubricity. With the low sulfur fuel we run these days you don't want to lose any lubricity!

I also recommend a Desert Cooler (see Kent Speers) for the radiator. Unfortunately the Desert Cooler is no longer made. I installed a redneck version made using the house water pump, a 12v 1/4" solenoid, and some 1/4" plastic tubing. Cost all of about $30. In use I've found that even with the Desert Cooler it takes a while to bring engine temps back down. I've started to switch on the cooler when the engine temps hit 190º. On long hills it will still creep up close to 200º but so far I've never gone over which is a vast improvement.

I've been meaning to post a write up of the project but life keeps getting in the way. Like right now I have to pack up and head to Crater Lake NP to spend the day with my girlfriend! It's our 8th wedding anniversary!

see ya
ken

Re: U300 Raideator Fan

Reply #8 – July 11, 2015, 12:59:12 pm

Great information Ken, I had a misting system on the eagle with a 8_92 so I will look into that. Thanks again for the insight.

Re: U300 Raideator Fan

Reply #9 – July 11, 2015, 01:29:34 pm

Brent, per the Detroit manual I use 50/50 blend ethylene glycol in my system. The system holds about 16 gallons.

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U300 Raideator Fan

July 10, 2015, 03:13:12 pm

Re: U300 Raideator Fan

Reply #1 – July 10, 2015, 05:34:34 pm

Re: U300 Raideator Fan

Reply #2 – July 10, 2015, 05:49:52 pm

Re: U300 Raideator Fan

Reply #3 – July 10, 2015, 06:15:54 pm

Re: U300 Raideator Fan

Reply #4 – July 10, 2015, 11:03:25 pm

Re: U300 Raideator Fan

Reply #5 – July 11, 2015, 09:41:06 am

Re: U300 Raideator Fan

Reply #6 – July 11, 2015, 10:21:28 am

Re: U300 Raideator Fan

Reply #7 – July 11, 2015, 10:59:37 am

Re: U300 Raideator Fan

Reply #8 – July 11, 2015, 12:59:12 pm

Re: U300 Raideator Fan

Reply #9 – July 11, 2015, 01:29:34 pm

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