Cummins ISB 340 Engine Overheating Overheat Fan Clutch Thermostat Cooling etc.

[basketball]

Contact me and I can supply more info.
Have specs on performance fan. H.P. to drive.
OEM fan, H.P. to drive

[krautkamper]

Cummins 2006-2009 with between 20,000 and 40,000 miles are notorious for losing the crappy Horton fan clutch that Freightliner installed. There was even talk of a recall but it never happened. If you are mechanically inclined you could do it yourself. The clutch is about $1000 and labor was about another $1000. I just went through it last fall....

[mickey53usa]

Basketball - Thanks for the response and the information. It will be headed to Freightliner this week. Yes, it has a Horton Fan clutch.

krautkamper - I have the skill, but probably not all the proper tools or the physical location to make this happen.

This part is covered under my Extended Maintenance Insurance, so I will not be out the full amount.

[basketball]

Hello all. Just replaced my Horton clutch fan on my 2008 Fleetwood Discovery coach.
ISB 6.7XT Cummins.
My Rad and inter-cooler had to be removed from coach.(Rear Rad) Had rad and inter-cooler pressure tested and cleaned. Rad shop did not find any blockage.
Comes out fast when you remove the correct bolts.
5- that hold the bottom of the rad
2- that hold the support arms.
4- that hold the pressure tank on top of engine
2- that hold the oil and trans dip stick to bracket
2- upper and lower rad hose
2- T-bolt clamps that hold air for turbo
14-that hold the rear bumper on
10- few others
The fan shroud comes out with the rad, do not remove from rad.(no need)
Had poor cooling when climbing grades. Yes it would overheat. This year of coach did not have a guard dog installed on the Horton clutch fan. (speed control of fan)

Also had a leak, which i thought was from the water pump weep hole. It was not!!!
It was from the upper rad hose, the clamp had rusted and broke. Stainless clamp. Replaced with a t-bolt clamp.
The four bolts that hold the clutch flange to the serp pully are inverted TORX. Bad choice for bolts, no room for removal. Had to cut the shaft of the clutch fan to gain access to the flange. The flange has concave bolt holes, cannot cut off bolt heads.
Cut flange in the middle, removed spacer and welded 4 nuts onto the bolts that hold the clutch fan to the serp pully. The bolts then can be removed.MAKE SURE THAT YOU USE THE CORRECT LENGTH OF NEW BOLT TO RE ATTACH. THEY CAN BE TO LONG. FAN CLUTCH WILL NOT SPIN.

Superior Eng does not make the high performance fan. This fan is a MULTI-WING FAN and can be purchased from Larry at SuperiorTurbo.com. A new spacer will be required (longer) Larry can send specs for OEM fan and the Multi-wing fan. Look at the H.P. used to drive OEM fan and Multi-wing fan.

Basketball

[RichKimball]

Sorry to hear about the trouble removing the clutch Basket.

After I cut a rectangular hole in my shroud at the top (done for cleaning at first) I had the clutch out and replaced in about 1 1/2 hours. Removed clutch up through that hole. (hole is covered by sheet metal plate for normal op)

Later...a very kind man sent me a Guard Dog for install. I love the performance of the cooling system now with the GD installed.

BTW...the hub bolts are simply 12pt socket head. Standard tools used for removal.

[basketball]

No room to get a socket on because of concave flange. Distance between clutch flange bolts and back of fan is not wide enough for socket and ratchet. Could not move them with a wrench.
10mm wrench is very short

Thanks

[RichKimball]

Originally Posted by basketball

No room to get a socket on because of concave flange. Distance between clutch flange bolts and back of fan is not wide enough for socket and ratchet. Could not move them with a wrench.
10mm wrench is very short

Thanks

Well...okay...so you say. But for anyone else that might read this thread....I did it...no problem....twice actually. Used a 12pt wrench to break free. Was able to hand turn after that.
Happy trails.

[basketball]

After cutting off the clutch fan shaft and being able to remove fan for maximum room, still not enough room. Could be a different serp pully on mine.
Welded on 4 nuts to the bolts and used my air impact gun to remove bolts. It was apparent that these bolts were installed with Locktite (blue, I would assume) The air gun did remove them, but it did have to work. I did have a 2 ft snipe on the wrench when trying to remove bolts. This resulted in striped bolt head. At that point had to do to plan B. Cut it off in the middle of the fan flange. I could have cut the $150.00 spacer off, but I wanted to re-use it on the install.


Thanks Mervman for your info.
Happy trails

[RichKimball]

Real sorry to hear about all the trouble you had. I would have killed myself if it had been me.
For reference here is a pic of mine.

[skyking421]

I hope this great thread is still open. Finally got to take a cross country trip and the overheat problem started and is bad.


I can't find the fuse panel for the clutch fan. It's crazy, since a factory placard says "Electrical Components and Rear Fuse Panel under Left Rear Valance Door". I have searched under the coach near the muffler on drivers side and lifted the valance panel for the basement A/C on the pass. side, as well as searching possible cover plates in basement compartments. No luck.


This is a 2010 Winnebago Journey 34Y with the Cummins 6.7L ISB engine.


From what I get from the info here, it seems that the fan clutch needs 12v power to shut OFF the fan. The sensors turn off the fan (with 12v) until the engine reaches a certain temperature, then the ECM drops power to the relay, the relay drops power to the clutch and the fan engages to cool more.


My fan clutch blows hard on startup, then shuts down in a few minutes. Supposedly normal. I have to check, maybe with a ribbon, to see what the fan is doing during overheating. I'm hoping it is a stuck relay. If not, I guess it's the clutch, although it's not leaking.


I'm familiar with relays and usually fix them. I wonder if this relay is sticking closed (12v on). The electro-magnet on these relays are generally strong, but the release spring is not. If the spring does not open the relay, the fan will have 12v and stay in dis-engage mode.


Please help me find the fuse compartment on this 2010 Journey 34y!
Thanks in advance,
Richard

[skyking421]

I also notice that the air blowing out of the radiator, only blows hard from the top 1/3. The lower 2/3 does not have much air flow when parked. I bought a roll of plastic ribbon and saw flow form the top while driving. I will put another ribbon near the bottom to see the result there. Yesterday, I cleaned the radiator with a hose nozzle set on "jet". Was not dirty on the outside. Looking from underneath, I didn't see any debris blocking the radiator, but I need to inspect better to see the fan side of the intercooler.


Now near Moab with hills and heat.



Richard

[wolfe10]

Originally Posted by skyking421

Yesterday, I cleaned the radiator with a hose nozzle set on "jet". Was not dirty on the outside. Looking from underneath, I didn't see any debris blocking the radiator, but I need to inspect better to see the fan side of the intercooler.


Richard

YES, the vast majority of the debris will be on the font of the CAC (first "filter" in the air flow).


Look at the lower perimeter, inside the fan shroud with a strong flashlight.


Let us know what you find.

[mickey53usa]

On mine the relay in question is behind the breaker panel in the left rear compartment.
They found my fan clutch bad after using the Freightliner procedure that I provided to them. Be a couple months before I can give it a test.

[skyking421]

The more I think of it, the more I believe that the air flow through the radiator is a big problem. See my post #235.


Air passing through the radiator is the only way it will cool and the faster air flow the better. You can easily feel, with your hand, that there is virtually no airflow through the bottom 2/3 of the radiator. There is a high flow of air blowing out the top 1/3 and the air is very hot. I tied two plastic ribbons behind the radiator to see them in the rear view camera. One ribbon on top and the other near the bottom. While driving, I could see the upper one blowing straight out, but never saw the lower one. I'm assuming there is little air flow on the lower radiator, even while driving.



I crawled under and took these photos of the CAC. I also wiped the CAC with a paper towel. A tiny bit of grey coating came off. Doesn't look very dirty.



Today's photos of the CAC (intercooler) side, from peeking in the shroud.
2nd photo is zoom of 1st photo.





I'm concerned that the airflow problem is making only 1/2 of the radiator useful.


Can anyone help by seeing if their airflow is similar to mine? Just starting while cold should have the fan engaged for a couple of minutes and putting your hand in the airflow, top and bottom, with tell right away.


Thanks all for you help with this perplexing problem.
Richard