Radiator losing water

I have a 2002 Tundra that I purchased brand new years ago. I have never had any issues other than some bad fuel a few months ago. Lately, everytime i check my water level in my radiator, it's low on antifreeze. The truck has never run hot, no signs of a leak, no water in the oil, no drips in the driveway or at work in my parking spot and the truck has never run hot. The temp guage has never moved so I'm clueless as to why i'm losing water. I read a post that said it's probably a water pump leak that can't be discovered until the pump is removed. Any help here would be appreciated.

 

Possible to pressure test the cooling system to find a possible leak??

 

Coolant can escape while under pressure while car is running and it may not leave a trace....thru weep hole for instance. As TX-TRD said, pressure test should be considered and sometimes the only way when you can not visibly see any indications with engine running !

 

Listen to TX and Bubba, pressure test and be patient when doing so. Had the exact situation in my Impala. When hot I would get seepage from the lower radiator hose due to a weakend spring clamp. Never a drop on my driveway but the leak would empty the expansion tank every 3 months or so.

 

I had this go on for YEARS with my 93 toyota pickup. Finally got bad enough to drip at a grocery store, it was a cracked hose, only leaked at higher RPMs and always dried out on the way home so I could never find it.

I had a cracked radiator on a subaru once that would spray at 3K rpm but not leak a drop when you looked at it at idle.

 

Also, check your transmission dipstick. Will take you all of 30 seconds and will either give you piece of mind, or ruin your day.

 

Change the cap
Cheapest of trouble shooting.

Could be evaporating depending on how fast you are losing it

 

2002 doesn't hurt to do a pressure check. I bought mine used 2015 with 75K, and suspected a leak. It cost me over $1000. I drained it to change a hose that was kinda hokey and walked away and saw the dog hanging around when I walked back around the corner. I would bet he didn't drink it, but wasn't going to find out. He spent the weekend drunk on my tab. They infuse about a fifth of everclear in a 20lb dog over a couple of days to block the metabolism of the EtOH.

That Monday it was the off to the dealer to verify no leaks. I think they did a coolant exchange on the factory certified process and left a big ass air bubble in it. Dog had a great weekend and I had to listen to the wife bitch that I had killed the dog. I mention hookers and blow and the dog's like hell yeah these days and wants a drink

 

As was stated pressure testing the cooling system is the best way to check for a leak but when was the last time you did a timing belt/water pump replacement? Water pumps can have leaks that are hard to see. Do you notice a sweet smell in the cab? Heater cores can leak and not leave any moisture signs.