Pinhole in coolant overflow tank?

[riderdan]

So last week my 88 developed a small coolant leak. About a hand span worth of coolant on the driveway in the morning. It was so slow that it basically dried out if I didn't drive the truck for a day. Life was pretty busy so I didn't get to checking it out until today...

I picked up my kids from school in the truck this afternoon and when I got home the leak was worse. Some coolant had run down behind the air cleaner drum. Not enough to change the level, but enough to make a moderate mess. The lid seal seems OK and no coolant was visible on the top of the reservoir, so I don't think it's the cap.

I checked each of the fittings where hoses lead to and from the coolant reservoir and they were all dry. However, when I removed the coolant tank the place where it rests the underside was wet with coolant. Both ends of the tank were dry and all the fittings were dry. I couldn't determine if/where the actual leak was, but I'm thinking there might be a pinhole in the bottom of the tank.

Has anyone else experienced anything similar? I could order a new tank and hoses, but I was thinking I'd ask the experts before I spend any (more) money in case its something else.

TIA.

 

[orgnal]

So last week my 88 developed a small coolant leak. About a hand span worth of coolant on the driveway in the morning. It was so slow that it basically dried out if I didn't drive the truck for a day. Life was pretty busy so I didn't get to checking it out until today...

I picked up my kids from school in the truck this afternoon and when I got home the leak was worse. Some coolant had run down behind the air cleaner drum. Not enough to change the level, but enough to make a moderate mess. The lid seal seems OK and no coolant was visible on the top of the reservoir, so I don't think it's the cap.

I checked each of the fittings where hoses lead to and from the coolant reservoir and they were all dry. However, when I removed the coolant tank the place where it rests the underside was wet with coolant. Both ends of the tank were dry and all the fittings were dry. I couldn't determine if/where the actual leak was, but I'm thinking there might be a pinhole in the bottom of the tank.

Has anyone else experienced anything similar? I could order a new tank and hoses, but I was thinking I'd ask the experts before I spend any (more) money in case its something else.

TIA.

Can you pressure test the reservoir with a loaner kit from Auto zone and such? I am still inclined to think it is the reservoir cap. That is what it was in my case.

McReddy