Cooling system overhaul on a Lexus 1UZ engine

[Clint_LJ78]

Good day everyone, I recently purchased a 1991 Toyota Land Cruiser LJ78. The previous owner had a 1UZ engine installed about 12 years ago. The engine is running fantastic but the cooling system is starting to show signs of wear. The previous owner installed a second, smaller radiator as well to help keep the engine cool during long trips.
The original radiator is still installed with an electric fan. I replaced the thermostat the other day and noticed a lot of rust particles in the water. I can only assume that this is from the radiator and that I will need to consider to replace it urgently. I am planning to rip the old primary radiator and fan out to replace it with a new radiator and fan setup. I suspect the secondary radiator may still be good enough to just clean properly and put back in again.
I would appreciate it if anyone could assist me with a diagram or suggestions on how to go about replacing the cooling system. The engine is still completely standard and no modifications has been made. Thanks in advance guys! Cheers!!

 

[cribbj]

Hey Clint, welcome! The key words I picked up on in your post were "....electric fan." Most of us drank that Koolaid years ago that an electric fan was an upgrade, then later discovered it didn't cool as well as the mechanical.

If I were you I'd do the following:

1. Flush the cooling system really well with a radiator flush that is suitable for aluminum.

2. Remove the radiator and have it flushed/cleaned professionally, fins straightened, trash removed from between fins, etc.

3. Replace the electric fan & go with a truly upgraded model (highest wattage you can find) with a full coverage shroud,, or go back to an OEM mechanical fan.

4. Replace thermostat, hoses, etc.

After all this, you should be good!

 

[Clint_LJ78]

Hey mate, thanks a lot for your advice. I will certainly go and get those radiators serviced. I know just the place (now that you reminded me of them!!). I reckon best will be just to pull both radiators out and start fresh with installing new pipes and clamps while I wait for the radiators to be sorted out.

 

[Zuffen]

To flush the block there is a drain on each side of the block about level with the 2nd cylinder from the front.

I use Ford electric fans from a Falcon and no doubt Ford anywhere in the World will have an equivalent fan available.

My Rover has never overheated and it's worked pretty hard in its life.