I'm leaking coolant in my truck. Had a pressure test done and we could not find any leaks. I replaced the hose between the reserve tank and the radiator, and it is still leaking.

I'll drive it for about two days, and the coolant is already gone from the reserve tank, but the radiator is still full. It's always full, I have never had to fill it, but the reserve tank is always empty.

So I have three questions:
1. What else could it be?
2. How can I test it from home?
3. I've been filling it with water, and the cold months are approaching. How do I drain the radiator to refill it with coolant?

Thanks,
Ralph

 

Mine was doing the same thing. Not loosing coolant and fast tho. Dropped it off at my friend's dad's shop. 2 hours later he call me and said the only thing he found was a loose hose clamp. Hasn't leaked sence then.

 

Could be Cap, Mine did that when I bought it.

 

Maybe there is a crack in the reservoir tank and the coolant is leaking out there. Another note is that it passed a pressure test but the engine and system could have still been hot. Your mystery leak could be when the system is cool and fittings and pipe retract. I know it tough to find leaks when there are no puddles.

GL with it.

** Your rad drain plug should look like a butterfly nut on the lower side or back of the rad. Just open that up and it'll drain.

 

Ok, I clamped both ends of the hose between the reserve tank and the radiator, and it fixed the problems. Thanks for everyone's input. Now, is there a way I can drain the water and replace it with coolant? Thanks!

 

i'll post pics for ya tom of the drain plug its real simple i have mine tore a part right now