Cooling Concerns On A Hot Day (3 Viewers)

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Why did you discontinue use of the black hub clutch?
I freaked when my truck overheated on the highway and the AC cut out. Also, I noticed a crack in one of the fan blades and decided to replace it. So while everything was out, I figured I might as well replace the clutch as well. I will add that my AC didn't cut out today with the new fan and clutch, but 225F is just too hot for comfort.

At this point, this is what I have:

New Aisin fan blade
New Aisin blue hub fan clutch unmodded
New Toyota T-stat installed and coolant flushed 5k miles ago
Toyota brass radiator (bought used) with 230K-ish miles on it
New Toyota radiator cap installed and there is no evidence of leakage.

I also have the LCP aux fan installed as well, but that has not helped. I'm thinking that either the brass radiator is clogged, I need to mod the fan clutch, and/or the T-stat is not working appropriately, or installed wrong? Maybe I should go back to green coolant? It may be coincidence, but I never had this issue with Prestone green.
 
as others have said, check fan clutch, flush system with cleaner if necessary, an electric pusher fan is cheap and a great thing for traffic, the most effective item that has kept my engine cool is hood vents, just completed a trip to and from the Rubicon and we hit 117 f and the highest i got was 216.
 
I freaked when my truck overheated on the highway and the AC cut out. Also, I noticed a crack in one of the fan blades and decided to replace it. So while everything was out, I figured I might as well replace the clutch as well. I will add that my AC didn't cut out today with the new fan and clutch, but 225F is just too hot for comfort.

At this point, this is what I have:

New Aisin fan blade
New Aisin blue hub fan clutch unmodded
New Toyota T-stat installed and coolant flushed 5k miles ago
Toyota brass radiator (bought used) with 230K-ish miles on it
New Toyota radiator cap installed and there is no evidence of leakage.

I also have the LCP aux fan installed as well, but that has not helped. I'm thinking that either the brass radiator is clogged, I need to mod the fan clutch, and/or the T-stat is not working appropriately, or installed wrong? Maybe I should go back to green coolant? It may be coincidence, but I never had this issue with Prestone green.
why a used radiator? def replace that for new
 
I freaked when my truck overheated on the highway and the AC cut out. Also, I noticed a crack in one of the fan blades and decided to replace it. So while everything was out, I figured I might as well replace the clutch as well. I will add that my AC didn't cut out today with the new fan and clutch, but 225F is just too hot for comfort.

At this point, this is what I have:

New Aisin fan blade
New Aisin blue hub fan clutch unmodded
New Toyota T-stat installed and coolant flushed 5k miles ago
Toyota brass radiator (bought used) with 230K-ish miles on it
New Toyota radiator cap installed and there is no evidence of leakage.

I also have the LCP aux fan installed as well, but that has not helped. I'm thinking that either the brass radiator is clogged, I need to mod the fan clutch, and/or the T-stat is not working appropriately, or installed wrong? Maybe I should go back to green coolant? It may be coincidence, but I never had this issue with Prestone green.
Fan clutch oil to 30k for sure but an aluminum radiator would probably make a difference.
 
The stock 80 cooling system has always been marginal, hence the factory option of having an additional electric fan and @LandCruiserPhil has filled that gap nicely. I have been a lover of all electric fan cooling systems for year.s From back in the 80's V8 Granada, V6 capri and anything I owned soon had the stock mechanical fan thrown away. I continued this as I grew older and could afford more expensive vehicles including a 6.0 V12 with a 5 speed manaul gearbox in a XJ12C, yep that's the coupe., and yes I fitted it with twin electric fans.

DONE PROPERLY going ALL electric has so many advantages and few disadvantages.

I know I rudely shouted 'done properly' but I hear so many 'my friend did this and fried his motor' or 'my relays burnt out and the van stopped working' lines it is unbelievable! So given I have been fitting electric fans on anything that moved for so many years I feel I am well placed to recommend them. Living in Spain we have warm temperatures most of the year round and some incredibly hot summers and this has not phased any of the vehicles fitted with all electric systems. I thought the main advantage lie with most cars here are diesel as is my 80, but a guy n the UK tried a system similar to what I was using and went to Europe and hit some incredibly hot temperatures in his petrol 80 with no issues, remember he was off road a lot of the time and well loaded.

Remember I am a mechanic and have virtually lived under the hood my whole life, so with 50+ years experience I am not about posting up a project with untested BS. With the 80 I did start with using the US Lincoln two speed fan and this worked fine however Ford moved to a PWM or 'pulse width modulation' fan, this is a multispeed fan driven with a special controller. this meant that increasing the fan speed in relation to motor speed or AC demand made it even more efficient than the two speed unit. When I could hear the baring going on the second hand fan unit I had sent over I decided to purchase a new one, the system was working great at this point. The I found that new OE units were no longer available, they had been bought up by the dragster and street/strip guys and girls, the secret was out. New units were available but only from Mexico.....lets not go any further with that, there was also a lot of confusion over what were two speeds and what was the single PWM version.

Not wanting to introduce any unreliability into my system I replaced the Fan with a Mercedes unit. This is a PWM, but there is a guy in the states who builds the controllers. The fan complete with shroud just fits the 80 diesel radiator but if I understand it correctly they are the same size as the petrol version anyway, with just hose positions differing?

Installation is a doddle as is the wiring, other than the fan and controller if I had to add anything it would be a heavier alternator, which it seems using the guide from @Photoman then another easy and worthwhile upgrade.

Add up the pros and cons and you will be pleasantly surprised how the conversion will increase the efficiency not only of the engine but also of the AC system.

As an aside there are nay sayers, and quite rightly too, we need balance, but not from those that have math qualifications that have 'done the numbers' and come up with quotes about needing 300 hp for the electric fan to work, no honest these people exist.

You find will everything you need to know in my long running thread. Builds - My LC 80 thread. - https://forum.ih8mud.com/threads/my-lc-80-thread.365673/page-32#post-13929657

Many thanks

Regards

Dave
 
Lose the secondhand brass/copper radiator and get a decent aluminium radiator.
 
Why did you discontinue use of the black hub clu

The stock 80 cooling system has always been marginal, hence the factory option of having an additional electric fan and @LandCruiserPhil has filled that gap nicely. I have been a lover of all electric fan cooling systems for year.s From back in the 80's V8 Granada, V6 capri and anything I owned soon had the stock mechanical fan thrown away. I continued this as I grew older and could afford more expensive vehicles including a 6.0 V12 with a 5 speed manaul gearbox in a XJ12C, yep that's the coupe., and yes I fitted it with twin electric fans.

DONE PROPERLY going ALL electric has so many advantages and few disadvantages.

I know I rudely shouted 'done properly' but I hear so many 'my friend did this and fried his motor' or 'my relays burnt out and the van stopped working' lines it is unbelievable! So given I have been fitting electric fans on anything that moved for so many years I feel I am well placed to recommend them. Living in Spain we have warm temperatures most of the year round and some incredibly hot summers and this has not phased any of the vehicles fitted with all electric systems. I thought the main advantage lie with most cars here are diesel as is my 80, but a guy n the UK tried a system similar to what I was using and went to Europe and hit some incredibly hot temperatures in his petrol 80 with no issues, remember he was off road a lot of the time and well loaded.

Remember I am a mechanic and have virtually lived under the hood my whole life, so with 50+ years experience I am not about posting up a project with untested BS. With the 80 I did start with using the US Lincoln two speed fan and this worked fine however Ford moved to a PWM or 'pulse width modulation' fan, this is a multispeed fan driven with a special controller. this meant that increasing the fan speed in relation to motor speed or AC demand made it even more efficient than the two speed unit. When I could hear the baring going on the second hand fan unit I had sent over I decided to purchase a new one, the system was working great at this point. The I found that new OE units were no longer available, they had been bought up by the dragster and street/strip guys and girls, the secret was out. New units were available but only from Mexico.....lets not go any further with that, there was also a lot of confusion over what were two speeds and what was the single PWM version.

Not wanting to introduce any unreliability into my system I replaced the Fan with a Mercedes unit. This is a PWM, but there is a guy in the states who builds the controllers. The fan complete with shroud just fits the 80 diesel radiator but if I understand it correctly they are the same size as the petrol version anyway, with just hose positions differing?

Installation is a doddle as is the wiring, other than the fan and controller if I had to add anything it would be a heavier alternator, which it seems using the guide from @Photoman then another easy and worthwhile upgrade.

Add up the pros and cons and you will be pleasantly surprised how the conversion will increase the efficiency not only of the engine but also of the AC system.

As an aside there are nay sayers, and quite rightly too, we need balance, but not from those that have math qualifications that have 'done the numbers' and come up with quotes about needing 300 hp for the electric fan to work, no honest these people exist.

You find will everything you need to know in my long running thread. Builds - My LC 80 thread. - https://forum.ih8mud.com/threads/my-lc-80-thread.365673/page-32#post-13929657

Many thanks

Regards

Dave
If I'm out in the middle of nowhere, I would prefer the redundancy of two fan belts running my fan!
I sure electric fans have there place, but it's not in my trail only 4x4 🤷‍♂️
 
If I'm out in the middle of nowhere, I would prefer the redundancy of two fan belts running my fan!
I sure electric fans have there place, but it's not in my trail only 4x4 🤷‍♂️

Your dead right! Whenever I am out on a trail I take the old mechanical fan with me. Having said that I have never has any issues but take it anyway. As I travel alone quite a lot into remote places I also take a spare starter, alternator, hub, Birf and flange blah blah..........yeh I know. :rolleyes:

Thanks for your input.

Regards

Dave
 
why a used radiator? def replace that for new
I slugged the motor going up a mountain over a weekend about a year ago. Blew the old radiator. It's my DD and I needed something asap. Someone had a used one for $100. I installed it on a Sunday and was ready for work on Monday. Been toying with the idea of replacing it for a few months now, but it's held up fine...until this last heat wave.
 
If I'm out in the middle of nowhere, I would prefer the redundancy of two fan belts running my fan!
I sure electric fans have there place, but it's not in my trail only 4x4 🤷‍♂️
I like having two fan belts also. I actually had a belt go bad and twist up on my first 80 a few years ago leaving me with only one to finish the day on. Even my 1978 Dodge Ramcharger had dual belts.
 
I slugged the motor going up a mountain over a weekend about a year ago. Blew the old radiator. It's my DD and I needed something asap. Someone had a used one for $100. I installed it on a Sunday and was ready for work on Monday. Been toying with the idea of replacing it for a few months now, but it's held up fine...until this last heat wave.
start with a new radiator, a used rad could have blockage and or ? causing problems, remove that from the equation immediately IMO....
 
start with a new radiator, a used rad could have blockage and or ? causing problems, remove that from the equation immediately IMO....
Yeah, I am probably going to get a new radiator. However, I just wanted to check on a few more things...

1) I checked the T-stat today. It opened at 191F, which was surprising. It has 82C etched on it, so I would have expected it to open at 180F. It did close at 180F, so maybe that's what it means.

2) I decided to flush out the radiator and block. Used a garden hose. Then dumpred 2 bottles of Prestone Flush and Cleaner ($3.44 a bottle at W-Mart so why not?) and distilled water. The T-stat is out and I'll drive it around for a few hours over the next couple of days. I'll then flush with more distilled water and then replace the coolant. We'll see how that goes.

3) I've ordered some 20k and 30k silicon diff oil to mode the fan clutch. I'm surprised at how difficult it was to get on Scamazon and various R/C shops. Some say there is a national shortage on this stuff. Anyways, I'll mix the two and make some 25k oil to use.

If the above doesn't work, then I'll install a new rad.
 
Yeah, I am probably going to get a new radiator. However, I just wanted to check on a few more things...

1) I checked the T-stat today. It opened at 191F, which was surprising. It has 82C etched on it, so I would have expected it to open at 180F. It did close at 180F, so maybe that's what it means.

2) I decided to flush out the radiator and block. Used a garden hose. Then dumpred 2 bottles of Prestone Flush and Cleaner ($3.44 a bottle at W-Mart so why not?) and distilled water. The T-stat is out and I'll drive it around for a few hours over the next couple of days. I'll then flush with more distilled water and then replace the coolant. We'll see how that goes.

3) I've ordered some 20k and 30k silicon diff oil to mode the fan clutch. I'm surprised at how difficult it was to get on Scamazon and various R/C shops. Some say there is a national shortage on this stuff. Anyways, I'll mix the two and make some 25k oil to use.

If the above doesn't work, then I'll install a new rad.
Why not just go with 30k?
 
Why not just go with 30k?
There were posts stating 20k and other posts stating 30k. My truck won't be a desert truck forever--I'm planning a move to more temperate locations soon--so I decided to split the difference.
 
There were posts stating 20k and other posts stating 30k. My truck won't be a desert truck forever--I'm planning a move to more temperate locations soon--so I decided to split the difference.
Just for info, your coolant and your clutch oil are thermostatically controlled. Cools when needed. You are just addressing the systems ability to efficiently answer that call.
 
Looking at aluminum 2 row radiators...
High end: 1993-1997 Toyota Land Cruiser Aluminum Radiator (FJ80) - https://wizardcooling.com/1993-1997-toyota-land-cruiser-aluminum-radiator-fj80/ for $819
Low end: 1993-1997 Toyota Land Cruiser Aluminum Radiator (FJ80) - https://wizardcooling.com/1993-1997-toyota-land-cruiser-aluminum-radiator-fj80/ for $195

I'd love to pick up a Ron Davis, but it's just too rich for me even with the military discount.

And I see time and time again that people recommend the OEM radiator. the OEM for the '94 is the brass 3 row, which people say doesn't cool as well as the aluminum radiators. So, are they talking about the '95-'97s? Are they a direct fit for a '94? Anything in between the above that you recommend? I see the Denso (Amazon product ASIN B0049GEC6O) for $250 and there's always the 1918, but those are aluminum and plastic construction, and I had a 1918 fail on me once.
 
Just for info, your coolant and your clutch oil are thermostatically controlled. Cools when needed. You are just addressing the systems ability to efficiently answer that call.
You mean the T-stat is controlled by temperature, right? That's why I checked it in a pot of hot water over the stove with a thermostat to see if it functioned at a given temp. If it didn't open at all in a pot of boiling water, then I would have gotten a new T-stat.
 
You mean the T-stat is controlled by temperature, right? That's why I checked it in a pot of hot water over the stove with a thermostat to see if it functioned at a given temp. If it didn't open at all in a pot of boiling water, then I would have gotten a new T-stat.
Yes. Just providing info as a whole in relation to the clutch as well. You impressed that 30cst vs 20cst would provide too much cooling and that you would not live in a hot climate long, where doing so would have a negative impact. It would not. The clutch also controls itself thermostatically.
 
Looking at aluminum 2 row radiators...
High end: 1993-1997 Toyota Land Cruiser Aluminum Radiator (FJ80) - https://wizardcooling.com/1993-1997-toyota-land-cruiser-aluminum-radiator-fj80/ for $819
Low end: 1993-1997 Toyota Land Cruiser Aluminum Radiator (FJ80) - https://wizardcooling.com/1993-1997-toyota-land-cruiser-aluminum-radiator-fj80/ for $195

I'd love to pick up a Ron Davis, but it's just too rich for me even with the military discount.

And I see time and time again that people recommend the OEM radiator. the OEM for the '94 is the brass 3 row, which people say doesn't cool as well as the aluminum radiators. So, are they talking about the '95-'97s? Are they a direct fit for a '94? Anything in between the above that you recommend? I see the Denso (Amazon product ASIN B0049GEC6O) for $250 and there's always the 1918, but those are aluminum and plastic construction, and I had a 1918 fail on me once.
get a denso, they are high quality, the plastic tops do fail over time but it takes awhile for this to happen. I usually recommend customers replace the radiators if the top plastic portion is showing any micro cracking.
 
Way back when I was a much younger man, my FJ40 had a marginal cooling system. And being almost broke, I didn't have the funds to replace lots of parts. That's when I found water wetter. Made enough of a difference that I was able to continue to run that rig until funds allowed for a new radiator. I've put water wetter in every rig I've had since.
 

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