100 Series Overheat (1 Viewer)

[flintknapper]

Whew. What a night. Man, I hope you're right on the leak at the inspection hole at the flywheel. Makes sense.

I got a real hose clamp on the leaking hose, and now everything seems mostly ok. I still get drips from that weep hole, but maybe it's just the coolant? It seems oily to me, but it could have picked some up on its way back there. Either way, I'm going to roll with it and see what happens. I'll keep an eye on AT, Oil, and Coolant levels (and milkshakyness) for a while. Maybe I got lucky and scared myself over nothing. Was pretty s***ty to be under the truck and then get rained on from multiple places...

Earlier question: this is a 2000 which I believe does have the A343F. I have a dipstick.

Up next is the water pump and timing belt. I'm hoping to do this at a more leisurely pace without my wife wondering when she'll get her rig back!

Yes, you have the A343F tranny. And yeah, just watch things for now. Do the T-belt and related components later, no need spooking the Wife with one thing right on the heels of another. DO check your heater Tee's if you haven't done them already.

 

[Seattle100]

Thanks for the tip. I did to the heater tee's about a year ago....after a catastrophic failure that began much like this repair did.

Is there anything else made of that same plastic that breaks down with hot coolant? The radiator was just as crubly as the Tee was...

 

[2001LC]

Whew. What a night. Man, I hope you're right on the leak at the inspection hole at the flywheel. Makes sense.

I got a real hose clamp on the leaking hose, and now everything seems mostly ok. I still get drips from that weep hole, but maybe it's just the coolant? It seems oily to me, but it could have picked some up on its way back there. Either way, I'm going to roll with it and see what happens. I'll keep an eye on AT, Oil, and Coolant levels (and milkshakyness) for a while. Maybe I got lucky and scared myself over nothing. Was pretty s***ty to be under the truck and then get rained on from multiple places...

Earlier question: this is a 2000 which I believe does have the A343F. I have a dipstick.

Up next is the water pump and timing belt. I'm hoping to do this at a more leisurely pace without my wife wondering when she'll get her rig back!

If coolant just a wipe off the garage floor and it will dry by tomorrow. If AFT just a wipe and it will be oily on garage floor tomorrow.

This is very important to get out air.
Bring engine to operating temp and drive reaching 2K RPM or just idle and bring RPM up to 2K. Make sure both front and rear heater on full hot. Turn on heater fan and feel the heat. It should be very hot, if not hot then coolant system not full. Either way let cool down for 8 hours with radiator cap (hopefully new OEM) on. Then remove cap after cool down, and top off radiator to the neck with coolant and then bring reservoir to max line. If using Toyota red 100 % you should have mixed 50/50 with distilled water. DO NOT PUT TAP WATER IN. If premix coolant no water should be added. Repeat bringing engine to operating temp with heater on full, cool down for 8 hours and check level in radiator daily. Do this until radiator will not take any more. This get out air bubbles out.

Tip: Park your truck so front is higher than rear. This put air bubble in top of radiator. Helps for when checking level in the morning.

 

[Seattle100]

Will do. And yes, Toyota red, mixed with distilled water, and a new oem cap. Amazon couldn't get the Denso Radiator to me before Friday, so I bit the bullet, and paid top dollar at the dealership, which comes with foam and a new cap.

 

[Seattle100]

Last update, just because it might help someone else some day.

After getting it all sorted, I kept adding fluid every morning. After a few mornings, I started thinking it was a lot of fluid. I park on the street, so it's hard to see the red puddle that must have been there.

Then I noticed a bit of red crust on one of my heater Tees. I decided to check the hose clamps and maybe replace with better ones, and the second I touched it, it turned to dust. Then I remembered:

Last year when my heater T failed and I replaced it, I only replaced the Hot side that failed. My advice to you, when you replace the hot side, do the cold side too. By my count, it's only about a year behind, and you might have a look at the top of the radiator at the same time. If I had pulled the top hose off the radiator I would have see how crumbly the plastic was that held it all together and could have avoided this whole mess.

I think that is every piece of that type of plastic in the cooling system. The 2 heater Tees, and the Radiator. All 3 should should be replaced just before 19 years and 190k miles.


I think that Tee was leaking the whole time, which led to a low coolant situation, combined with a failed radiator cap (maybe), created enough pressure to explode the radiator on the HWY. That's my best guess anyway.

Thanks again for all the help.