Is new fan clutch really needed when changing water pump? (1 Viewer)

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Hi there,

I've been searching this forum and the internet for some info regarding the water pump and fan clutch repalcement and couldn't really find much related to the need of a new clutch if the water pump is being replaced.

I'm working on the LX450 coolant system and the idea is to refresh most of it. I got the rig 4 months ago and the PO has never done it, the truck has 233k miles on the clock. Fortunately, everything is going well so far, full flush done, new thermostat, new "Denso" rad, new phh, new rad hoses and water bypass pipe, all ready to be installed. Just finished the crank seal and oil pump cover gasket.... :beer:

However, after a month of research, I have decided to replace the water pump as preventive maintenance. To my surprise a LOT of people are commenting that if the water pump is replaced, the clutch should be too, not sure about that. None of these 2 parts are falty at the moment and after more research, it looks like the new AISIN blue fan clutches are coming out of the factory with not enough oil :eek: also not sure about that but it looks like there are tons of posts in here about modding the new AISIN blue clutch.

So my 2 questions are:

1. If I replace the water pump, does the fan clutch really need to be replaced as well? It looks like the one that came with the truck is an Eaton clutch but I might be wrong. I'm attachig some pics in the end of the post for reference.

2. Is it really needed to mod the new AISIN blue fan clutch out of the box to have it working properly? It doesn't really make sense to me seeing people buying a new oem fan clutch just to open it, remove the oil, adjust the valve and replace more oil than it came with. I get that people are doing that to trigger the clutch earlier, more frequently and for longer periods to fight 100F+ heat but other than cool the engine under extreme usage and in very hot weather, I don't really understand the benefit of doing that job. I'm in the NW and don't really see a need for ultra-cold cooling system.

Any light or advice on this subject would greatly help. Thank you!

IMG_2212.jpeg


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Did your truck overheat before the work? If not, run it. If it goes bad in the future, it is a simple job to replace.
 
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^
Agree. You have it out anyway. May as well change the fluid and put it back in. Replace when you need to. You'll
have ruled out the fluid and not the fan clutch at that point.
 
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Did your truck overheat before the work? If not, run it. If it goes bad in the future, it is a simple job to replace.


No, it wasn't overheating but the rad was yellow and about to crack. As I have to replace it i thought it would make sense to refresh the whole cooling system. I think i'll just re-install the current clutch, no problems with it so far. Thanks for the advice.
 

Bambusiero

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I cannot see what one has to do with the other? Removing the fan clutch takes only minutes - kick that can down the road and and deal with it whenever it needs it.
 
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For $8 I would clean your current, crack open, drain the best you can and fill.


Can't hurt, probably better. If needing more.... well then replace I suppose.

Thanks for sending the link. 2 questions:

1. When draining the current clutch oil, does the oil need to be heated up to be easily drained? I see that some folks are putting the clutch opened in the oven until it reaches 90F or so but I believe that opening it and positioning like this "/\" for 2 days would work.

2. Do those JIS screws have a spec torque on them?
 
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I cannot see what one has to do with the other? Removing the fan clutch takes only minutes - kick that can down the road and and deal with it whenever it needs it.

That is what I thought when I started seeing people recommending changing both... maybe a marketing move. Thanks for confirming. I'll keep that metally clutch moving for now.
 

retrofive

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Thanks for sending the link. 2 questions:

1. When draining the current clutch oil, does the oil need to be heated up to be easily drained? I see that some folks are putting the clutch opened in the oven until it reaches 90F or so but I believe that opening it and positioning like this "/\" for 2 days would work.

2. Do those JIS screws have a spec torque on them?
Pretty much. I put mine in the oven for a little bit and drained over night.
Torque. I don’t think so.
There are so good threads on procedure here. I will see if I can dig one up.
 
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I'm going to go against the trend and say replace it.
The fan clutch is an integral part of the cooling system and yours is now 24 years old. You say you want to "refresh" the cooling system, but you're leaving an important part out. I would go directly to 80 Series 1FZ-FE Modified OEM Toyota Blue Fan Clutch.

You should also CAREFULLY inspect the plastic fan for hairline cracks where the blades meet the core. Having one blow apart at speed can be very exciting.
 

flintknapper

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I'm going to go against the trend and say replace it.
The fan clutch is an integral part of the cooling system and yours is now 24 years old. You say you want to "refresh" the cooling system, but you're leaving an important part out. I would go directly to 80 Series 1FZ-FE Modified OEM Toyota Blue Fan Clutch.

You should also CAREFULLY inspect the plastic fan for hairline cracks where the blades meet the core. Having one blow apart at speed can be very exciting.


^^^^^

Good advice on both points.

No way I would do the rest of the cooling system and not be certain of the two items mentioned above (Fan Clutch condition and the Fan Blade itself).

Brittle Fan.jpg

Aisin Cooling Fan.jpg

Aisin Cooling Fan2.jpg


And truth be known....if anything doesn't need to be replaced its the Water Pump. These are known to last nearly forever in most cases. I pulled mine at 316K miles (for the same reason as the OP) and found it to be in perfect shape, still clean, still turning freely, NO leaks.

But I'd definitely make sure my fan clutch was working properly (fluid not degraded, bimetal strip still working) and grab your fan blade and check it for flexibility.
 
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Thanks for sharing the link. I came across that one during my research but the question that stays after all is... do people mod the AISIN clutches because they don't respond well in high temps or is it because the "lack" of oil on a new one is a problem on the part lifetime?
 
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I'm going to go against the trend and say replace it.
The fan clutch is an integral part of the cooling system and yours is now 24 years old. You say you want to "refresh" the cooling system, but you're leaving an important part out. I would go directly to 80 Series 1FZ-FE Modified OEM Toyota Blue Fan Clutch.

You should also CAREFULLY inspect the plastic fan for hairline cracks where the blades meet the core. Having one blow apart at speed can be very exciting.

Thanks for the advice. I have been thinking about the Wits End clutch but it is almost $200 more than a new stock AISIN clutch. That is why I have been researching to see what are the benefits of 1st: Modding the AISIN stock clutch myself VS getting a modded one from WitsEnd? 2nd: Do I really need to mod it or get a modded one to ride in the NW mild temps? 3rd: Can't I just get a stock AISIN clutch and just throw in there knowing that it will last around the same amount of time that the one that came with the rig from the factory has?

The fan blades seem to be ok for now. Just cleaned them and they look quite brite and smooth.

Thanks for the help!
 
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^^^^^

Good advice on both points.

No way I would do the rest of the cooling system and not be certain of the two items mentioned above (Fan Clutch condition and the Fan Blade itself).

View attachment 2354495
View attachment 2354496
View attachment 2354497

And truth be known....if anything doesn't need to be replaced its the Water Pump. These are known to last nearly forever in most cases. I pulled mine at 316K miles (for the same reason as the OP) and found it to be in perfect shape, still clean, still turning freely, NO leaks.

But I'd definitely make sure my fan clutch was working properly (fluid not degraded, bimetal strip still working) and grab your fan blade and check it for flexibility.

Hey flintknapper, thanks for the info. One question, did you mod the clutch installed on the new blades shown in your pics?

The water pump bearings on the LX are scratching when I turn the pulley. It looks like they are built to last around 300k (close to the mileage of yours when it broke). The Lexus has 233k miles in it and the water pump, clutch and blades are fine but for $50 on a new oem water pump now can give a little more ease of mind when driving it later and "while i'm in there", why not right! Now paying $80 on a new AISIN clutch knowing that I have to open it, drain it and replaced the oil and change the quantity inside sounds like more work than I actually need to perform, in my case.

Thanks for sharing the truth. The help in this forum is indeed amazing!
 
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You can replace the clutch with a new Aisin and count on the same performance you've been getting. Or you could replace the oil in the one you have, which is likely spent and not doing the job as well as it used to. That's not to say you need to use a higher CST silicone oil than stock. Modding the clutch is for someone looking for more cooling performance. There are drawbacks to modding the clutch, specifically it will drain horsepower and mpg.
 

flintknapper

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Hey flintknapper, thanks for the info. One question, did you mod the clutch installed on the new blades shown in your pics?

The water pump bearings on the LX are scratching when I turn the pulley. It looks like they are built to last around 300k (close to the mileage of yours when it broke). The Lexus has 233k miles in it and the water pump, clutch and blades are fine but for $50 on a new oem water pump now can give a little more ease of mind when driving it later and "while i'm in there", why not right! Now paying $80 on a new AISIN clutch knowing that I have to open it, drain it and replaced the oil and change the quantity inside sounds like more work than I actually need to perform, in my case.

Thanks for sharing the truth. The help in this forum is indeed amazing!


I have a 'modified' blue fan clutch....BUT I live in Texas (read very hot here). YOU would not benefit in any way from a fluid modded fan clutch in your climate. However, I would suggest replacing your current fan clutch with a stock Aisin Blue Clutch.

If your fan blades feel flexible....then you're good to go with that.
 
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You can replace the clutch with a new Aisin and count on the same performance you've been getting. Or you could replace the oil in the one you have, which is likely spent and not doing the job as well as it used to. That's not to say you need to use a higher CST silicone oil than stock. Modding the clutch is for someone looking for more cooling performance. There are drawbacks to modding the clutch, specifically it will drain horsepower and mpg.

That is the info that I have been looking for. Thanks for sharing. I didn't know about those drawbacks either, could you explain the reason for the clutch mod draining horsepower and affecting the mpg?

I think i'll wait and get a new AISIN stock clutch and finally be done with the cooling system. If needed, i'll mod it later and still have the Eaton one as a spare just in case.

Well, onto the next item on the list.....that phh :borg: ow boy....
 

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