Radiator leak / Spring in Radiator?

06 SR5 Quad cab 4.7 - 240K

We have a leaking radiator and am planning its replacement when we found a small spring in the radiator between the fill cap and the return line to the radiator from the WP. maybe this spring came from the water pump? Do these water pumps have internal reliefe valves in them of some sort?

I'd like to do this right and fix whatever issue there is while I am doing the work.

Where could this spring come from?

I am the second owner and have only had the truck for about a year.

Hoping to not learn where this spring came from the hard way... Phoning a friend. I've got $1M dollars in suit case for anyone that can tell me where this spring came from.

Thanks in advance.

 

Any chance a previous radiator cap went kaput and spilled it's guts?

 

I just went and looked at the cap and it doesn't look 18 years old.

That could be it... but i'd rather ask a stupid question that do something wrong. Thank you for the reply.

Any other ideas from the gallery? there is $1M on the line

 

The only other spring I can think of is the one on the thermostat.

 

Yep. Radiator cap spring. Important component too.

 

This ^^

Be sure to replace with Denso radiator when you get there. Don't buy from scAmazon or fleaBay unless you want a damaged unit. NAPA can get them for you, RockAuto and Summit will be able to get them cheaper, and typically ship w/o damage.