I just replaced coolant reservoir, new hose, and new clamps and the hose is still leaking from the connection point of the hose to the overflow tank. This happens when the car is off. Any ideas? Could it be a bad headgasket or radiator cap or air in cooling system? How could I check

 

Are you sure it's leaking from there, or leaking from radiator side and running down the outside of the hose to the tank where it drips to the ground? What clamps you using?

 

yes I am certain it's coming from there. I am using some plumber clamps right now because no parts store near me has the size I need. I'm not sure if the clamp is the issue though as before there was no clamp even on that side and it didn't leak. It just started leaking after temperatures got below freezing for some reason.

 

What kind of hose and what is the inside diameter? Is your coolant reservoir vented?

At the end of the day this is all pretty simple. You got a nipple with a certain OD, and need a hose of a proper ID, and a clamp suitable for the OD of the hose. Like your actual hoes, not the old hoes that you threw away. But a clamp can't make up for bad fitting hose (over sized) -- the hose has to be right.

Worm screw clamps do not provide uniform clamping force around the circle. That's why spring clamps are used. But the spring clamps are only suitable for certain range of hose OD. Your replacement hose is not necessarily the same OD as the stock hose, so you need a spring clamp for your hose. Unfortunately it's a bit of trial and error because you don't have access to the part drawings with the specs.

 

There's something incredibly wrong with our society when state-of-the-art software prefers spelling of hoes over hose.

 

Maybe


1. The hose is too large. If it easily slipped on maybe you need the next smaller size.

2. Clamp is not tight enough...I usually go with a screwdriver till it stops...let it heat up / cycle, then come back a few weeks later, and f leaking give it a litle more tuturns after the hose gets adjusted / aged

3. Maybe its too tight and cracked the plastic tank

 

I had the same problem on my 88 with a new GM coolant reservoir. I replaced it with another new GM one and guess what: That also leaked. The hose was the correct size. I ended up using two hose clamps next to each other and filed the tank plug a little bit round. That did the trick for me and it hasn't leaked for three years (fingers crossed).

 

Okay so I just bought a new hose and it fits much better and more snug. We will see how it holds up though

 

I will try that next if this new hose I just got doesn't work! Thank you!

 

A better mousetrap: