Hi all! First post here. I appreciate anyone who can help. I am wondering, how much leaked coolant residue is considered normal? We have a '07 Suburban 1500 5.3L.

Situation: My dad noticed some coolant residue where the lower radiator hose clamps onto the thermostat housing. To deal with the situation swiftly, he:

1. Replaced the thermostat
2. Replaced the aluminum thermostat housing
3. Replaced the lower hose (Napa branded, Gates?)
4. Even replaced the OEM clamp with a heavy duty T-Bolt style hose clamp
5. Replaced the coolant with new Prestone Dexcool

When he runs tissue paper at the tip of the hose where it clamps around the nipple of the housing, a tiny bit of coolant residue keeps showing up. I really don't know too much about the proper functioning of radiator and hoses. My question is... is this suppose to be a 100% perfectly sealed system with absolutely nothing leaking or evaporating out of the thing? Am I missing a gasket or something? Because there was no OEM gasket if I recall...

My dad is worried that the Napa/Gates non-OEM hose might be the culprit.

Thanks to anyone who can help!

 

it should not leak anywhere at anytime. check the water pump housing and water pump gaskets

 

+1 do verify that its not leaking somewhere else and misleading you to the hose.. and yes its remotely possible the hose has a pinhole leak...
If its not the water pump or other obvious cause, and the leak is not reaching the ground... I would give it a few weeks to see if it will resolve or reveal its self...