DP started overheating after a repair

[hershey]

2001 36' Fleetwood Expedition, 270 hp Cummin's and 5 spd Allison.
We are fulltimers, summer in WY and Winter in S CA. Last Nov just outside of Winslow AZ my radiator fan self destructed. Lost belts and fan pillow block. Repair facility had a hard time finding the correct parts and even the correct belts. After a week in their shop I was back on the road. Winter is cool but in May I found my first 90 degree weather on I-17 between Phoenix and Flagstaff. Started running a lot hotter than it has ever run.
I made it to Albuq with no real problem and thoroughly cleaned the radiator which I do as normal PM. BTW: Slobber tube is rerouted under radiator. Traded cars and now the new toad is 800 lbs heavier and traveling in 90+ temp, the MH still overheats on long grades.
My theory is: the repair facility replaced the fan with a different fan than the original and it isn't pulling enough air. I finally arrived at our summer destination and will do a more careful check of belt tention and number of blades on the replacement compared to the 9 blades on the old fan. I unhooked the toad on the last long grade today and it still overheats. I guess I'm looking for any other suggestions.

[hershey]

Kayteg1 wrote:
Hmmm.. garage that put blades backwards on good garage list?
Sure customer service stands up to garage errors, but I would think twice about going there.
This way, or the other I would love to see pictures?

I posted it on my FB page. On edit: Sometimes you don't have a great choice of garages when your dead in the water on I-40. Actually, I was quite comfortable with this garage, had a lot of trauma fining the right parts for the reassembly and all in all, they did a very good job, I think the repairman just had a brain fart and was used to working on larger trucks, and if that were the case, the blade would have been correct. Heres the UrL: https://www.facebook.com/gene.hirschman

[mpierce]

We are all human. Mistakes are made. I give them credit for accepting blame, and offering to make it right. Especially since they do not have it there to look at themselves.

[Kayteg1]

Hmmm.. garage that put blades backwards on good garage list?
Sure customer service stands up to garage errors, but I would think twice about going there.
This way, or the other I would love to see pictures?

[Farmerjon]

That's terrific and the way it should be. What is the name and location of that garage? I want them on my good garage list.

[hershey]

Update: I got a hold of the garage that did the repair in AZ. Got thru to the GM and he was a bit tentative at first in believing that they did the error. After a few more words, very calmly, I explained the way it is facing and he agreed that it is indeed backwards. He asked for some time to check with his service dept and called me back. He indicated since I was nearly 1000 miles away, he would arrange for a local garage to reverse the fan blade for me. What more could I ask for. Wish every garage or dealership took care of business the same way.

[hershey]

Thanks for the input and verification. I'll call the repair facility in Winslow AZ tomorrow but I just can't help but believe I'll be blow off. I'll report my finding.

Thanks to wolfe10 for getting me pointed in the right direction.

[PaulJ2]

I agree it is installed backwards. The inside curv should scoup/grab the air and push it through the radiator. Make sure of the rotation first. If wrong-it should be on their dime.
A backwards installed fan will have reduced air flow as most of it will just slip sideways off the outside curve of the blades.

[Ivylog]

You should be seeing the back of the "C"of the fan blade, not the cup. Turning it around should solve your problem.

[hershey]

Your correct about the oil from the engine, (blow by valve) will coat the surface of the radiator and of course restrict air flow and cause overheating. Side radiators don't seem to have the same problems and probably a better choice but....when you buy what you buy, you get what you get. My blow by has been re-routed early on and my radiator stays very clean, with PM I give it a heavy power wash from the rear forward and this has worked well for over 80,000 miles. My airplane comparison is only for the shape of the prop and the effect to move air, thats exactly the same weather in your desk fan, airplane or engine fan.
I just checked another DP here in the park and my theory is confirmed, the fan is indeed installed backwards. The air is being pushed by the outside curve of the fan instead of the inside curve. I'll check at least one more DP before committing to the task of reversing the fan. Thanks to all.

[hershey]

Kayteg1, I reread your post can't tell what your are really saying other than rear radiators are "tricky animals". The url you presented doesn't have anything to do with the subject at hand but back to your post, we may be saying the same thing. Normally air is sucked thru the radiator by movement and the fan but on rear radiators, the fan sucks the air from the engine side and blows it thru the radiator backwards. I'm presently looking around the RV park we are presently in to find a similar RV that someone will let me crawl under 🙂
Thanks for the info.

[Kayteg1]

Read what I wrote wolfe again.
It is 100% correct.
I can only assume you misread my observation and applied it to rear radiators.
I did google the subject and it can make hot topics like on this forum.
http://www.jalopyjournal.com/forum/threads/rear-mounted-radiators-how-come.426663/

[hershey]

The air on an airplane is pushed from the inside curve of the prop. Using the same logic, I would be pushing the air thru the radiator from the outside curve of the prop. I'm trying to get a picture to post, Thanks for your patience. BTW: Wolfe10 your absolutely correct in the air flow on a rear DP. Thats happening but its not the intensity that I think I need. Go to this URL to see photo on FB. https://www.facebook.com/gene.hirschman

[wolfe10]

Kayteg1 wrote:
All the radiator I know would suck OUTSIDE air and blow it into engine compartment.
Rear radiators are tricky animals for sure and I never used one.

INCORRECT. On 100% of the rear radiator coaches, the fan PUSHES the air from the front through the CAC and then the radiator.

Trying to PULL air from the huge vacuum behind a coach on the road would be total folly.

And, to check direction of flow, merely start the engine and use cruise to raise RPM in neutral to about 1200. Stand behind the coach. You should feel a LOT of air being PUSHED out the back!

[hershey]

Fan blows into the radiator from engine side to rear of MH, I think this is backwards, the arc should be facing the engine, not the radiator.