Coolant tank empty

So I purchased a 1st gen 3.4, the engine and the rest of the truck seem immaculate and the previous owner took great care of it but one thing we were both perplexed with. When I went to test drive it, the coolant resivor tank was bone dry, he had replaced the radiator within the last 25k miles. He said he never noticed it empty and must be a crack in the coolant tank. He did say it never over heated and on the test drive I had my scan guage plugged in and it never went over 195 degrees.

I drove it 3 hours home in stop and go traffic in 100 degree weather and again never went over 195 degrees. That night I took the radiator cap and noticed the coolant looked low in the radiator too which had me concerned. I obviously added oem toyota 5050 coolant into the tank. Should I add some directly into the radiator?

Also should this be of concern? My biggest concern would be possible head gasket but haven't noticed any tell tell signs (over heating, white smoke, etc). Could the low coolant be because it wasn't burped right?

I should add the new radiator is a Denso and new radiator hoses were replaced as well as a new radiator cap

 

He most likely didn’t fill the radiator all the way would be my guess. But couple questions.

1. Why did he replace the radiator?
2. Did you only add coolant to the radiator and not the overflow?

I would fill the radiator have the front of the truck slightly uphill so any air rises out the fill. Idle until thermostat opens and make sure the radiator is full. Then fill overflow tank to the full line. Run it a few days and make sure your not loosing coolant.

 

I only added coolant to the overflow and not directly to the radiator. Should I add some directly into the radiator? He replaced a few items (he's here on tacomaworld) and gave me a bunch of oem parts he got to swap out for future maintenance (belts, water pump etc). I could see he was a stickler for maintenance and he seems pretty honest so I wasn't concerned about him replacing the radiator due to the pink/brown milkshake although anything is possible I suppose

 

What do you mean by milkshake? That could be a term for when your transmission cooler and coolant mix and cause contamination in your transmission.

I would definitely add coolant to the radiator, leave the cap off with the front of the truck elevated until your coolant system burps all the air out. Make sure the radiator is full and reservoir is full and see what she looks like after a few hundred miles of driving or so.

How many miles on the truck?

 

193k miles. Stupid question but as long as the engine didn't overheat, no damage was done for the low coolant right?

 

while your concerns are real I wouldnt get too excited over having to add small amounts of coolant to the overflow tank every so often... there are lots of places that coolant can seep out of and not leave a trace. If it gets to filling the overflow every day then thats a problem. Even though the radiator cap is new that is the first thing I would get checked.

 

No you can run it with no coolant as long as it doesn’t get hot haha. Your water pump could be seeping as well. Just see if you loose anymore once your all full and go from there.

 

Look at the heater hose connections at fire wall, the heater control valve, the hoses coming from under the intake (tube to hose connection) also look at the oil cooler on side of engine, there are coolant hoses to that as well. Hoses age, they crack internally and the coolant wicks thru the threads in the hose rubber. The hoses at firewall are right above exhaust cross over for left exhaust manifold, lots of heat baking those hoses
This is ONE possible source.
In my 4Runner I could smell coolant while driving and having the rear window open, never could find a diff it even leak until I looked at these hoses, replaced the, no more smell, no more leak.
Also Check and see how fast the cooling system pressurizes after cold start up, should take several minutes, if it pressurizes quickly there is possibility of head gasket failure (it doesn’t have to over heat for this to happen) coolant will slowly escape this way as well, but could get worse over time. (This happened on my 3rd gen 4Runner)