View Full Version : FJ-40 Radiator Replacement

12-31-2007, 08:28 PM
The radiator on the FJ-40 leaked when I purchased it and was the primary reason I put it on a tow dolly to get it home. The PO used JB Weld to stem the flow so we could run the engine when I was looking it over. If anyone who can use/repair it wants an old radiator with a leaky top seam, it's yours for the asking.

As it turns out there was a new, never installed 4 row radiator on Craigslist. I did some research and found this is the same radiator you get at radiatorbarn and has a good reputation among those that have replaced their FJ-40 radiators on MUD.

This is the first time I have ever replaced a radiator. From a General Tech perspective this is a job that as a novice, I would be willing to help someone with. All in all it is pretty straight forward and is one procedure the CHILTON manual does have very well described in the 1970-88 Repair Manual. That said, it was not without a bit of drama.

My project for yesterday was to remove the old radiator. The part of the process of draining the radiator did not go smooth. I put a tube on the drain plug, loosened it up and watched a little fluid drain out into the tub. I removed the cap to release the vacuum and a little more fluid drained out - no where near 17 quarts. I figured the leak must have been bigger than I realized and the fluid had mostly drained out at the POs house. Well, as soon as I disconnected the bottom hose, the rest of the 17 quarts came out. A fair amount of it made it into the tub, the rest on the garage floor. We did take about 10 minutes to get the old radiator out (see below) and then my boys and I proceeded to spend the next couple of hours cleaning up our mess.:rant: I was too wrapped up in the moment to stop and take pictures and wish I would have.

The part of the process of removing the radiator goes very smooth. Loosen up the clamps on the top and bottom hoses. Remove four bolts, remove the drain plug and the old radiator just lifts out.

Today with a couple of phone calls to coordinate logistics of picking it up, this is what I had.

After about 30 minutes, here is what in looks like installed.

Tomorrow, this is what is going in it.

12-31-2007, 08:48 PM
Looks good, sorry to hear about your spill. I have had my RB radiator in for a little over a year and it works great! Almost too well, I have a hard time getting up to temp in teh winter.

Rezarf <><

01-01-2008, 10:19 AM
Rezarf, I just read your thread on MUD. Regarding the radiator drain plug, did you stay with the standard plug or fabricate something new?

01-01-2008, 10:21 AM
I used what came with the radiator, my old one was boogered up.

Shark Bait
01-01-2008, 10:57 AM
I have a stock new Toyota drain plug I can't use. Someone is welcome to it. the radiator in my 40 must not be a stocker. I ended up using a plastic plug.

01-01-2008, 06:35 PM
I have a stock new Toyota drain plug I can't use. Someone is welcome to it. the radiator in my 40 must not be a stocker. I ended up using a plastic plug.

Thanks for the offer Chris, the radiator I bought is not a stocker either so the drain plug might not work. Good news is I found a tub at Ace hardware that is big enough to catch it all the next time I drain.

01-01-2008, 06:35 PM
Couple of questions. For those of you that have replaced your radiator, or totally drained and re-filled. How much fluid actually went back in? How strong a mixture of antifreeze to water is too much?

I put in a new radiator and it filled up with about 2.5 gallons; 1.5 gallons of antifreeze and 1 gallon of water. I ran the engine until it got up to temperature then turned on the heater for a while. The radiator is full, there has been no settling/dropping of the level.

So is 10 quarts too few, seems like it to me but that is only based upon my expectation (from the Chilton's book) that it should be 17 quarts. Also, is a 60 to 40 ratio to much antifreeze?

01-01-2008, 06:56 PM
<snip> Good news is I found a tub at Ace hardware <snip> QUOTE]

Since when did they sell FJ40 tubs at Ace Hardware? Score, Ricardo!!


Happy New Year Everybody!

01-01-2008, 07:09 PM

Since when did they sell FJ40 tubs at Ace Hardware? Score, Ricardo!!

That's right this group has a language all its own. Oops, I should edit that to have read "... big basin for catching antifreeze (built for goofs so they don't spill it all over their garage floor) ":cheers:

A bit off topic, but if they are not "tubs" what to allyouall call the basins in your bathrooms that are filled with hot water and used for bathing?

Rogue Leader
01-01-2008, 08:11 PM
A Wash Basin.

01-09-2008, 12:46 PM
An update to close this out.

I spoke with a couple of you at the monthly meeting who suggested that I park (and block) on the driveway incline and then put the front end up on jack stands to get the radiator fill valve to be the highest part of the cooling system. Then run the truck up to temperature with the radiator fill cap off and let the fluid and air cycle around so any air in the system could leave.

With that thought in mind, it occured to me that I could hook up the water block heater and have it circulate the fluid and get air to the radiator cap. I did this and was able to get another pint of liquid (water) into the system. Then for good measure, I did the whole driveway thing.

After these steps, I'm reasonabley confident that not all of the fluid was drained from the system when I swapped the radiator and is the reason for the difference between what I the manual says should be the capacity and what I was able to get in. Of course I'll be keeping a close eye on the fluid level just in case.