Very slow coolant leak

JEFF713

MEMBER
2001 TOYOTA AVALON
6 CYL
169,000 MILES

My 2001 Avalon has 169,000 miles and has had a very slow coolant leak for several years now. It is slow enough that I have simply added 6 ozs. Or so of coolant to the reservoir every few months. (I never filled it to the MAX line, usually kept the level about half way between min and max. Now that my bottle of coolant is empty I'm thinking it might be time to find the leak.
I replaced all hoses and replaced the coolant almost a year ago and have never noticed any leaks or coolant on the parking pad. I understand that most water pumps have a "weep hole". The pump is original. How do I confirm if the pump is bad or not? Any other ideas?

2 Replies

KHLOW2008

MECHANIC
41,815 POSTS

When leakages are minimal, you would not notice any leakages from under the vehicle. Signs of leakages would be oxidation at leaking points, usually the joints of hoses.
A pressure test would indicate where the leakage is coming from.
In fact most water pumps has 2 weep holes, one on top and the other at lower portion. If you don't see any dripping from the lower weep hole, it is not leaking. Usually the leakage would be bad if the water pump bearing is failing and has excessive side movement.
If the pump seems to be noisy during running, it should be failing.