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Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked on

Yahoo Message Number: 56704
Thanks to excellent and patient phone and e-mail support from Doug at Country Boys RV Services in Eugene, after he walked me and my ohmmeter through a few simple tests while on the road, we determined that the problem was not with the fan controller, but almost certainly with the coolant sensor for the latter. No one had one on the road so I ordered one from Colton while I drove 2000 miles with fan locked on high losing 2 mpg.
On my C-12, the coolant sensor is a brass male (3/4 in bolt head) threaded into the bottom of a 1.5 foot horizontal coolant pipe made of some sort of metal that is attached inline from the main coolant hose coming off the top of the engine and attached to another hose on the other side. I have put what I consider to be a hell of a lot of torque on the sensor but it seems frozen in the pipe fitting that it is threaded into. Suspect corrosion internally or dissimiliar metal issues? I am concerned I might snap off the pipe fitting if I torque too much. I do not think penetrant will work since the sensor is pointing downward. Any suggestions? Propane torch on female pipe thread fitting? Heat up engine to operating temp? Anyone done this?
Moral of story, by the way, is that if your hydraulic fan starts malfuntioning, do not rush to replace very expensive fan controller until conducting simple resistance tests at plug that attaches to sensor. There are both dedicated coolant and air temp sensors for the fan controller that can go. They cost only about $30 dollars each.
For those of you who are fairly technical but not knowledeable enough to always know exactly what to do, I highly recommend Doug's phone/email support service. He is at (541) 935-0848

Rich 2002 Magna

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #1 –
Yahoo Message Number: 56705
Rich, have an C-12,and just bought 2 sensors for 18.95 ea, from Bresden, distributor for Sauer Danfaus

Ray G

03 Magna 6267

Feb 21, 2010 10:10:53 AM,

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #2 –
Yahoo Message Number: 56706
? Heat easily with propane torch and get some wax on it while its hot (candle stick or small birthday candles if its a tight spot)

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #3 –
Yahoo Message Number: 56710
Thanks Ray. I will purchase one of each for future events. I paid double and one source was even more.

Rich 2002 Magna

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #4 –
Yahoo Message Number: 56711
Ray, can you provide contact info for Bresden? Cannot find.

Thanks

Rich 2002 Magna

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #5 –
Yahoo Message Number: 56713
Rich, go to www.sauer-danfoss.com Look at the top for tab for distributors, sends you to a map for what state you need.

Ray

03 Magna 6267

Feb 21, 2010 07:29:12 PM,

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #6 –
Yahoo Message Number: 56732
When I replaced the turbo cooling-air sensor, I used a torch, worked like a charm.

Ray

2000 Intrigue 11040

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #7 –
Yahoo Message Number: 56736
Thanks Travman. So you heated up the metal that the sensor is screwed into, not the sensor, I presume? I am looking to borrow a torch at the moment.

Rich

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #8 –
Yahoo Message Number: 56783
I used one of those small propane cylinders with an inexpensive burner that attach to the cylinder and becomes a portable torch. Yes, I heated the metal all around the sensor while putting torque on the sensor. It came loose fairly quickly after beginning the heating process.

Ray

2000 Intrigue 11040

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #9 –
Yahoo Message Number: 56833
Success! I purchased this little mini butane torch (POS) but it did the job. Replaced sensor, and that was the problem. 10 minute job with right tools. Did not drive it yet, but at least now with engine cold, fan is turning over nice and slow and electrical resistance is right on at plug. Advice: Carry a very deep 3/4 in. socket, a torch, extra fan coolant and air sensors, an ohmmeter and pipe thread sealant. Depending on which way your fan goes, it could save you a fortune in diesel or stop you from being dead on the road from overheating. It can go either way. BTW, in answer to someone's question, I noticed at least on my C-12 the fan air sensor is sitting on the big silver air pipe living just below where the coolant sensor is. So far, 8 years and 75k miles on fan controller, no issues (knock wood...) Thanks to all for your great help. After 2000 miles running at about 187F, my poor little CAT is looking foward getting nice and warm again! Soon...

Rich 2002 Magna

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #10 –
Yahoo Message Number: 56844
Nice job Rich! I think I'm going to have to do the same to my 370 ISL. My temps are too cool (186?) and my MPG is 7.5 on a good day. How much coolant did you have to drain and do you remember what the resistance readings are supposed to be on the sensor? One thing though, my fan runs slow at idle right after startup? Thanks for any advise you can provide

Larry, 03 Allure, 30856 W/Cummins ISL 370

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #11 –
Yahoo Message Number: 56847
Rich, what resistence reading did you record, and did you check the fan speeds verses temperature.

Ray G

03 Magna 6267

Feb 26, 2010 08:13:10 PM,

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #12 –
Yahoo Message Number: 56849
DUH! Sorry for the dumb question Rich. I just remembered and found the OHM resistance table here in the file section. Larry

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #13 –
Yahoo Message Number: 56871
I have not driven it yet, but I will. I am so sick of going under the radiator what I will be watching is coolant and tranny temps on Silverleaf. I can see very clearly when fan kicks up since the coolant temps drop like a stone.

Rich 20002

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #14 –
Yahoo Message Number: 56872
Larry and Ray,

As I recall at about 70F the sensor resistance is around 3k ohms on both. (My bad one was pulling 27k ohms. Check with engine cold is best. About two cups of coolant came out. My fan ran on high, period. Remember, while the sensors are the first thing to check, if they check out, the fan controller itself is the problem. Make sure the first thing you do is to check the two wire plug for voltage. There is a fuse up front for this and a few other things. One thing I realized is that this controller seems to operate puely off of air and engine coolant temp. No direct input from tranny.

Rich 2002

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #15 –
Yahoo Message Number: 56886
Larry,

My fan also does as I suspect everyone's does. The pump has a flow rating at both rated speed and idle speed. Considering the application I don't imagine a high flow rate at idle is necessary. After all the engine does not generate as much heat at idle or lower RPMs (500 to 800 range). Note that many trucks with hydraulically operated devices set the idle up to operate the device. Oil delivery trucks and log boom trucks come to mind.
The speed of the fan motor is tied to the flow rate of the fluid at lower RPMs.

Don Seager

2004 Allure 31046

Re: Removing Fan Cooling Sensor Advice: Update on Cooling Fan locked

Reply #16 –
Yahoo Message Number: 56899
That makes sense Don. Thanks for the clarification! Larry, 03 Allure, 30856

Removing Fan Cooling Sensor Advice: Update on Cool

Reply #17 –
Yahoo Message Number: 56707
What are you talking about...birthday candles ? Are we are missing some part of your message ? AL

00 affinity 5851

Re: Removing Fan Cooling Sensor Advice: Update on Cool

Reply #18 –
Yahoo Message Number: 56708
The gentleman was talking about how to get a stuck metal plug (sensor) out of a metal tube and I said heat it up and put some wax on it. The wax will work its way into the threads and allow extraction. I said candles or small birthday candles in tight spots works good. Sometimes people think of large bars of wax and I was just saying that small birthday candles (1/4" x 2 1/2") get into tight spots easier than a bar or a large candle. Hope this clarifies.

Re: Removing Fan Cooling Sensor Advice: Update on Cool

Reply #19 –
Yahoo Message Number: 56709
Roger, great idea, as are penetrants, only problem is that none of these will work since the sensor is pointing downwards, threaded into the bottom of the pipe. I have been advised that CC used a sealant of some sort and best option is to heat with propane torch. Need to get a torch.

Rich 2002 Magna
 

Re: Removing Fan Cooling Sensor Advice: Update on Cool

Reply #20 –
Yahoo Message Number: 56712
Rich,

Sometimes liquids will travel toward the heat source as with sweating copped tubing. If you apply the heat higher up and apply the wax or whatever below the heat it may creep upward into the threads.

Worth a try .

Don Seager

2004 Allure 31046

Roger, great idea, as are penetrants, only problem is that none of these will work since the sensor is pointing downwards, threaded into the bottom of the pipe. I have been advised that CC used a sealant of some sort and best option is to heat with propane torch. Need to get a torch.

Rich 2002 Magna

Quote from: "Roger Bryan"
The gentleman
was talking about how to get a stuck metal plug (sensor) out of a metal tube and I said heat it up and put some wax on it. The wax will work its way into the threads and allow extraction. I said candles or small birthday candles in tight spots works good. Sometimes people think of large bars of wax and I was just saying that small birthday candles (1/4" x 2 1/2") get into tight spots easier than a bar or a large candle. Hope this clarifies.

Quote
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