1993 FZJ80 Cooling System Overhaul

[ajax1]

Since you are pulling the radiator you have to disconnect the tranny lines at the bottom of it, could replace those also now

 

[midfat]

Why not just use an OBDII reader instead of a dedicated coolant temp sensor? Also, I'd recommend a complete set of constant tension breeze clamps to replace the standard hose clamps. Pretty sure @NLXTACY sells a complete set. Tightening the breeze clamps in tight spaces is so much easier. And if you're getting a new OEM radiator, it comes with a cap (at least mine did).

 

[Will Van]

Since you are pulling the radiator you have to disconnect the tranny lines at the bottom of it, could replace those also now

Do you have a PN on the trans lines?

Why not just use an OBDII reader instead of a dedicated coolant temp sensor? Also, I'd recommend a complete set of constant tension breeze clamps to replace the standard hose clamps. Pretty sure @NLXTACY sells a complete set. Tightening the breeze clamps in tight spaces is so much easier. And if you're getting a new OEM radiator, it comes with a cap (at least mine did).

Great idea! I’ll look for the Breeze clamps from NLXTACY.

I thought '93 trucks had OBD I?

I'm getting a Ron Davis radiator. It comes with a radiator cap, but I didn't know if I should swap it for OEM Toyota.

 

[ajax1]

Hard to say my oem lasted 22 years replaced with another oem so... no part number for tranny lines you'll have to look it up sorry

Do you have a PN on the trans lines?



Great idea! I’ll look for the Breeze clamps from NLXTACY.

I thought '93 trucks had OBD I?

I'm getting a Ron Davis radiator. It comes with a radiator cap, but I didn't know if I should swap it for OEM Toyota.

 

[baldilocks]

The trans cooler hose that you might consider replacing with an oem part is the one that transitions from the cooler line to the radiator passenger side. It has a formed shape that helps keep it away from the the fan and crank pulleys. The rest can be replaced with gates 1/2” tranny cooler hose purchased by the foot at most any parts house.

Yes, 1993 is obd1. That’s why I suggested a Koso.

This is a good time to go all the way and replace every single hose under the hood and while you have the PS plumbing removed, replacing the driver side motor mount is much easier. Motor mounts are rubber too. Mine were hard and cracked. Replaced my tranny mount too but Toyota calls it an Engine Isolater also.

 

[Shoredreamer]

Did I miss it or did you address the infamous PHH?? Check the condition of the heater valve too at the firewall center. With the rad out might as well do belts and the 2 pulleys to get that super quiet sewing machine idle for the Koso, I used a Glowshift sleeve on the upper rad hose that has worked great for 40000 miles now. I rebuilt my black hub fan clutch like @baldilocks but put 10000k and saw a definite improvement in cooling during summer. Whatever you do with your black hub, don’t scrap it.

 

[ewillis]

Did I miss it or did you address the infamous PHH?? Check the condition of the heater valve too at the firewall center. With the rad out might as well do belts and the 2 pulleys to get that super quiet sewing machine idle for the Koso, I used a Glowshift sleeve on the upper rad hose that has worked great for 40000 miles now. I rebuilt my black hub fan clutch like @baldilocks but put 10000k and saw a definite improvement in cooling during summer. Whatever you do with your black hub, don’t scrap it.

Black hub is KING!

 

[Will Van]

The trans cooler hose that you might consider replacing with an oem part is the one that transitions from the cooler line to the radiator passenger side. It has a formed shape that helps keep it away from the the fan and crank pulleys. The rest can be replaced with gates 1/2” tranny cooler hose purchased by the foot at most any parts house.

Do you happen to know the PN for the trans cooler line with the formed shape?

Yes, 1993 is obd1. That’s why I suggested a Koso.

Yes, but member @midfat recommended using an OBDII reader instead of a dedicated temp sensor, so I was confused.

This is a good time to go all the way and replace every single hose under the hood and while you have the PS plumbing removed, replacing the driver side motor mount is much easier. Motor mounts are rubber too. Mine were hard and cracked. Replaced my tranny mount too but Toyota calls it an Engine Isolater also.

I may have to put a limit on it somewhere. This "while you're in there" business is going to bankrupt me!

I'm thinking: radiator, water pump, thermostat, Landtank fan clutch, OEM fan, radiator hoses/breeze clamps, OEM belts, PHH, and the pre-formed trans line. Maybe pulleys too. Plus whatever I see while I'm in there.

Edit: Heater Control Valve too.

Did I miss it or did you address the infamous PHH?? Check the condition of the heater valve too at the firewall center. With the rad out might as well do belts and the 2 pulleys to get that super quiet sewing machine idle.

For the Koso, I used a Glowshift sleeve on the upper rad hose that has worked great for 40000 miles now. I rebuilt my black hub fan clutch like @baldilocks but put 10000k and saw a definite improvement in cooling during summer. Whatever you do with your black hub, don’t scrap it.

I still don't understand the differences between all the colored fan clutches. Why is a black fan clutch good?

 

[baldilocks]

The heater valve is inexpensive and recommended more than once here. I do not know the P/N to the trans cooler hose.

 

[Will Van]

The heater valve is inexpensive and recommended more than once here.

I’ll add it to the list.

 

[Desert Dino]

I installed a dry external temperature sensor reader from our experience in very hot climate, relying on WET sensor only is problematic in case of losing all coolant very fast you would not get warning of over hitting in time to save your engin.
I run my 1994 obd1 in parallel to get confidence that the reading is correct and it is very accurate.

I overhauled completely the cooling system including all new oil cooler in the engine, new CSF radiator all rubber hoses, water pump, new thermostat, all Aisin or OEM

I changed the 5 Treny oil houses to the radiator and treny cooler.

Still, I have worming problem when driving fast on the highway over 60 miles per hour
1. Adding another manually controlled front pusher electrical fan
2. Opening on the engine hood to release hot air
3. Blue fan clutch mod
4. Colder thermostat

 

[fz1boxer]

Desert Dino are 1-4 mods you are planning on making?
if you are having a problem with heat when running 60 don't do #1,but definitely #2.
what temp thermo stat are you running?
what ratio coolant?and which coolant?

 

[offroadvegan]

I grabbed a nice set of silicone radiator hoses on Amazon.

 

[Will Van]

I grabbed a nice set of silicone radiator hoses on Amazon.

I saw an HPS silicone hose set on Amazon. The feedback earlier in this thread was to stick with OEM rubber because the aftermarket silicone kits tend to leak.

How has your experience been with the kit? Any leaks?

 

[Dave 2000]

Only a couple of thoughts, if you like to keep the stock dashboard then do this:

93-97 Coolant Temperature Gauge Modification

I use an all electric cooling fan, there are mixed options about this but, at least there is some agreement that an electric fan will give you better AC.

My LC 80 thread.

Sudden water loss can be picked up instantly by this:

Cartek Coolant Level Alarm | Demon Tweeks.

Would this be the right time to fit an external transmission cooler?

Regards

Dave

 

[Dave 2000]

I saw an HPS silicone hose set on Amazon. The feedback earlier in this thread was to stick with OEM rubber because the aftermarket silicone kits tend to leak.

How has your experience been with the kit? Any leaks?

I have mine apart at the moment to replace all soft (and some hard) cooling lines/pipes, seriously thinking about silicone with constant tension clamps?

Regards

Dave

 

[Will Van]

Only a couple of thoughts, if you like to keep the stock dashboard then do this:

93-97 Coolant Temperature Gauge Modification

I use an all electric cooling fan, there are mixed options about this but, at least there is some agreement that an electric fan will give you better AC.

Sudden water loss can be picked up instantly by this:


Cartek Coolant Level Alarm | Demon Tweeks.

Would this be the right time to fit an external transmission cooler?

Regards

Dave

Thanks! I saw the writeup on the OEM temp gauge mod. I know I'm going to want a digital water temp gauge, so I hadn't added the OEM mod to the to-do list. It's a good reference regardless, so I'll put it in the links at the beginning of the thread.

I'm not too worried about a catastrophic and instantaneous water loss. I've never seen or heard of that happening. Plus, if the coolant system failed catastrophically and dumped 3 gallons of water out of the truck, don't you think you would notice an event like that (without a warning gauge)?

Doesn't the FZJ80 already have two transmission heat exchangers? A conventional liquid-to-air cooler on the DS front, and a liquid-to-liquid heat exchanger in the radiator? Are you saying you'd like to add/upgrade the cooler?

 

[Dave 2000]

Thanks!

I'm not too worried about a catastrophic and instantaneous water loss. I've never seen or heard of that happening. Plus, if the coolant system failed catastrophically and dumped 3 gallons of water out of the truck, don't you think you would notice an event like that (without a warning gauge)?

The FZJ80 already has two transmission heat exchangers. A conventional liquid-to-air cooler on the DS front, and a liquid-to-liquid heat exchanger in the radiator. Are you saying you'd like to add/upgrade the cooler?

Water loss can occur overnight for example, come out start up and you get an instant warning. A free a sudden loss dumping water over the exhaust and the resulting steam would be a good sign of a problem, what about a steady loss, unless you are an avid gauge watcher you may not notice until it is too late?

Transmission contamination by an internal leak ftom the rad can be costly, given how keen you are to get it done right, a seperate liquid to air cooler was just a thought.

Regards

Dave

 

[Will Van]

Water loss can occur overnight for example, come out start up and you get an instant warning. A free a sudden loss dumping water over the exhaust and the resulting steam would be a good sign of a problem, what about a steady loss, unless you are an avid gauge watcher you may not notice until it is too late?

Transmission contamination by an internal leak ftom the rad can be costly, given how keen you are to get it done right, a seperate liquid to air cooler was just a thought.

Regards

Dave

I agree with everything you're saying. There is a risk of water loss to the cooling system that you might not notice, which could lead to engine failure. But that line of reasoning could be applied infinitely (“What if XYX scenario occurs? ABC scenario? Etc.”) Then you're adding gauges for water temp, water level, oil temp, oil pressure, tire pressure, ATF temp, and voltage. I'd eventually like to do a turbo-diesel swap, so then I would also need boost pressure and EGT temp. There would be gauges everywhere! Haha!

I also hear what you're saying about the possibility of ATF contamination in the radiator. If you're running the radiator fluid and the transmission fluid separately, then there is no risk of contamination. I guess I would ask, how often has that happened? Is it a common occurrence?

With the standalone transmission heat exchanger, you are avoiding the risk of coolant/ATF contamination, but you’re also adding the risk of the ATF being outside it’s operating temp range. Running the ATF too cold is rough on the trans.

I am certainly not discounting any of those risks. But I am saying, we could brainstorm all day long about the potential scenarios that might lead to a failure, and then try to account for them. But then we're building a rolling science lab to combat remote potential risk scenarios. There’s a law of diminishing return.

Basically, I think the water temp gauge and the factory heat exchanger plumbing is probably enough. That's the way Toyota designed it, so it’s probably fine.

Regardless, I appreciate your input.

 

[jfz80]

Just curious but why? Other than Texas which is an ok answer but lots of good results with an OEM rad at about 1/3 the cost ..... plus it comes with the foam you were inquiring about as well.

Also your pic heavy posts make you a great candidate for a silver star membership

I'm getting a Ron Davis radiator. It comes with a radiator cap, but I didn't know if I should swap it for OEM Toyota.