It has happened to me! (Dreaded Fan Sensor - Crumbling Hose!)

[Stevedbvik1]

FWIW. The fan clutch is built by Mahle for Ford. Mahle supply’s fan clutch’s for many major OEM’s. Some of which also use the rubber hose. It appears to be OEM only and not purchasable from Mahle aftermarket suppliers.

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[FerdRanger]

It seems to simply be a bridge that keeps the wiring harness away from the serpentine belt, pulley, and fan.

mines not rotted but safety wired it and will keep an eye on it ?

 

[airline tech]

mines not rotted but safety wired it and will keep an eye on it ?

You know, I use safety wire all the time and never thought of that, it would at least keep it from spinning (clockwise) (+) safety.
I am stumped as for the actual reason for the hose vs solid support.
It is designed to flex some, but WHY?

It's there for more than just wire harness support and I feel it ties into (failure) mode.
Which is the (MISSING) answer, what is the designed failure mode, is a crumbling hose or broken hose a (sign of the fan clutch failing) early warning. ?‍

I would love to get my hands on a failed one, and take it apart, I am looking for wear or galling on the race the module rides on or front bearing wear allowing the fan to rock backwards.

 

[canyonslicker]

You know, I use safety wire all the time and never thought of that, it would at least keep it from spinning (clockwise) (+) safety.
I am stumped as for the actual reason for the hose vs solid support.
It is designed to flex some, but WHY?

It's there for more than just wire harness support and I feel it ties into (failure) mode.
Which is the (MISSING) answer, what is the designed failure mode, is a crumbling hose or broken hose a (sign of the fan clutch failing) early warning. ?‍

I would love to get my hands on a failed one, and take it apart, I am looking for wear or galling on the race the module rides on or front bearing wear allowing the fan to rock backwards.

Hey AT,
It’s basically a dynamic shock absorber that can deteriorate without a fail safe. That’s why the molded bend in the hose. I’ve suggested the use of a back up wire in the past but widely rejected. That’s ok. I really like all of your input here. Hopefully we can find a great solution to stop the damage others have experienced.

 

[Bsqrd]

Hey AT,
It’s basically a dynamic shock absorber that can deteriorate without a fail safe. That’s why the molded bend in the hose. I’ve suggested the use of a back up wire in the past but widely rejected. That’s ok. I really like all of your input here. Hopefully we can find a great solution to stop the damage others have experienced.

I think whenever I have to replace mine I'll use your idea and run a wire inside the tube as a backup.

 

[TJC]

There is nothing intelligent about the design. It is full of compromises. I can't wrap my mind around it. There is absolutely no safe fail mode. What worries me most is the deterioration rate. Is it a water fall event, or a slow process? This is really unknown right now. And that implies constant observation.

The only reason I have not changed to a heavy fuel line is that I suspect the softness of the hose is part of the design to keep the sensor from wearing too fast. The sensor needs to glide, but not be allowed to clock.

Maybe going to a silicone hose with a 90 degree bend is the best solution. It will not decay, and it is more flexible than fuel line. If the sensor wraps/rips the silicone hose we will have our answer. it is not the hose, but the sensor.

 

[canyonslicker]

There is nothing intelligent about the design. It is full of compromises. I can't wrap my mind around it. There is absolutely no safe fail mode. What worries me most is the deterioration rate. Is it a water fall event, or a slow process? This is really unknown right now. And that implies constant observation.

The only reason I have not changed to a heavy fuel line is that I suspect the softness of the hose is part of the design to keep the sensor from wearing too fast. The sensor needs to glide, but not be allowed to clock.

Maybe going to a silicone hose with a 90 degree bend is the best solution. It will not decay, and it is more flexible than fuel line. If the sensor wraps/rips the silicone hose we will have our answer. it is not the hose, but the sensor.

I’m thinking silicone tape at the attached points to preserve the elasticity of the design. Maybe that is what’s needed IDK.

 

[Bsqrd]

I'm thinking this might work as a replacement.

HPS Performance 3/8" ID, 10" Leg, 90 Degree Silicone Elbow Coupler Hose, High Temp 4-ply Reinforced, Black (HTSEC90-038-L10-BLK): Amazon.com: Industrial & Scientific

 

[TJC]

I'm thinking this might work as a replacement.

HPS Performance 3/8" ID, 10" Leg, 90 Degree Silicone Elbow Coupler Hose, High Temp 4-ply Reinforced, Black (HTSEC90-038-L10-BLK): Amazon.com: Industrial & Scientific

I'll let you know. I just ordered one.

I've been looking around locally, but never found just the right thing. This may be close enough to trim it to the same size.

Thanks for the link.

 

[TJC]

This just arrived in the mail. It will be a few days before I can test fit as I am recovering from appendicitis. Boy!! Came on suddenly and very painful! But I am over the hump. Antibiotics are wonderful things.

Here's a couple of pictures of the hose, Plenty long to cut to fit. I have not had the original off to see if they have similar flexibility. But a cursory look seems promising.

An update coming when it is test fitted. This one won't dry rot.

 

[Glocker]

This just arrived in the mail. It will be a few days before I can test fit as I am recovering from appendicitis. Boy!! Came on suddenly and very painful! But I am over the hump. Antibiotics are wonderful things.

Here's a couple of pictures of the hose, Plenty long to cut to fit. I have not had the original off to see if they have similar flexibility. But a cursory look seems promising.

An update coming when it is test fitted. This one won't dry rot.

Feel better!

 

[TJC]

Thanks, the pain comes in waves. Feels fine for a few hours then it acts up for a couple hours. But it is better than yesterday.

Update:
What I find interesting is that most doctors simply rush you to the hospital and remove the appendix. My doctor treats patients with this problem with a combination of antibiotics and has a 85% success rate. He monitors your fever (infection response) and if he can drop it, you are in no risk of the appendix bursting and risking death.

I am on my 3rd day of treatment (no food and lots of water) and feeling much better today. Day 1 and 2 were extremely painful. I spent the days walking around focused on the pain. Wife told me I had bouts of delirium. I called the doc at 7:30pm last night and asked him if he were sure this was working. He assured me it was. "These things just take a little time." By 10pm the pain had dropped and I have been pain free today. Seems he knows what he is talking about!

I want to eat but I am chicken. He says 5 days of fasting.

He really is an excellent doctor. Worth every penny for concierge service.

 

[got3fords]

Which is more likely, tranny failure or fan hose failure?

 

[ctechbob]

I'm tempted to look up the connector fittings and make about a 6" sacrificial wire lead and plug it between the clutch and the factory harness, that way, if/when it goes it will tear up the sacrificial connector and wires and not the factory ones.

 

[TJC]

I am working on the theory that the hose is either deteriorating, or weakening at the flex points due to repeated stress from the rotating sensor exhibiting variable resistance for whatever reason.

I'll be the first to say that It is shot in the dark.

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