I noticed a fresh leak while checking the oil level at a gas station. Since then, I've been monitoring the temperature gauge and the coolant reservoir. I've attached two pictures that highlight the apparent areas of the recent leak(s).

Before this becomes a major issue, are there any tests I can run to pinpoint the problem? Are there additional areas I should check for leaks?

Some relevant info about truck:
Recent coolant flush and refill with Toyota Coolant; performed by Toyota dealership (~ 6 months ago)
Mileage ~ 140,000
There are times when a sweet scent comes through the vents
Coolant reservoir is low
No signs or indications of overheating (yet)

https://postimg.org/image/usl87crwb/

https://postimg.org/image/jt00vrwcb/

Your first image seems like your water pump may be leaking. The WP is above the crank pulley (and slightly to the left).

Your second picture looks like maybe the top radiator hose might be leaking.

I would pull the top plastic timing belt cover and see what's going on. Once that is removed, you should be able to see where the leak is coming from.

PS. The stock temp gauge is essentially worthless. The needle won't move at all until the temp has risen quite a bit. I would suggest buying an Ultragauge/Scangauge or at the very minimum, an OBD2 reader that you can use with your phone to monitor actual coolant temp values.

I have an ultragauge and have the coolant temp as one of the displays that is always on. I also have an alarm set at 215 deg so if the temps ever get that high, it will set an audible alarm.

These engines do not fare well to being overheated.

Keep us posted.

Is there a particular OBD2 reader you can recommend ?

Thanks

I don' t think prestone would leak where your first picture points out. Looks like oil

Second picture, remove puddle of coolant under the hose, and check back after a day or two if it's back again. Then you found your leak.

Do not forget to top your coolant reservoir and radiator.

Coolant doesn't leak "up". I also think the bottom leak is not coolant, it doesn't look white and chalky when dry.

Clean up the radiator hose and if it comes back the hose needs to be replaced.

Looks like it's leaking between the upper radiator hose and the coolant outlet neck. Puddling up underneath on the outside of the TB cover and running down the inside of the cover and revealing itself in the 007 picture. May want to take the cover off and check the condition of the TB belt it coolant has been splashing on it. As far as your upper hose leak, make sure the neck isn't pitted and causing a leak. If it is, you can replace the part ($30) or fill in the "pits" with some sealant. Hopefully, if you fix this leak the sweet smell goes away because if it doesn't you've got a major job (heater core) to deal with. But fix the easy stuff first and go from there.

Like John mentioned above, it's clear as day you have a leak where the upper radiator hose meets the filler neck. Those necks can become pitted and get some built up deposits on them. I'd drain some of your coolant out the bottom of the radiator into a clean container so you can reuse the coolant. Remove the upper radiator hose off the filler neck and clean up the filler neck with some fine sand paper. Emery cloth like plumbers use to clean up the ends of copper pipe works well for this. Once you get all the deposits cleaned off the neck and the surface is smooth, you might find you will be leak free afterward even if you do have some pitting on the neck. I've done this exact thing with success on somebody's rig I was working on. Good luck!

jb weld works great for this. paint it on there, let it cure, and then sand everything down until it's level. i used it on my water pump gasket surface because it was corroded and pitted.

op, the easiest way to replace that neck is the unscrew all of those studs, slide the neck off underneath the fuel rail, and then buy 3 new studs, the gasket, and neck at toyota ($50 or so). takes an hour and you're done.

@thegipper - Thanks for the suggestions. Where I currently live, we got hit pretty heard with storm Quinn. Once the weather gets warmer I plan on removing the timing belt cover to see if other components were affected by the coolant leak...

@diverscale - I use Toyota red coolant, not prestone. And I agree with your assessment regarding the first picture...

@JRZEE2000TR4LTD - I would most likely purchase a new neck if it were pitted. And yes, I hope the sweet-like smell coming from the vents vanishes afterwards...

@mtbtim - Thanks dude!

@muellernautique - Good to know! Thanks!

Somewhat Not related: I was disappointed to see the leak. I really enjoy driving this truck; very versatile with a timeless look. However, the truck does have a good amount of rust on the frame/differential/suspension components. I'm hesitant to dump money into it. I may have to post pictures of the rust,in the future, to get some opinions on the condition.

Get your coolant leak fixed first then worry about the rust.

Definitely post some pictures so we can get an idea of how bad it is. Rust is relative term. Guys in AZ would see my frame and faint but anyone in the rust belt would see it and say...Meh

What is important is the degree of rust and has it compromised the structural integrity of the components in question. If it hasn't, the rust can be removed and steps can be taken to prevent/reduce it from coming back.

That is what I had to do to my frame and it is rock solid. I'm using LPS 3 to prevent any new rust and so far it is working excellent.