I know I have a small leak around the water pump, and another probably at the timing chain, maybe, but this is unrelated (I think.) Every time I drive, I lose a reservoir's worth of coolant (almost exactly.)

I can't find the leak. All the hoses look good, and the puddle is under the passenger side front (not the reservoir, which would have actually made sense). I took off the shroud, and the little rubber/asbestos thing underneath. The thing underneath is covered in coolant, and there are metal holes in the frame below the radiator that have coolant in them. So I'm leaning toward "it's the radiator" and I might as well replace it because it's probably the original. But I'm curious if anyone recognizes these symptoms enough to suggest I replace something else instead (or at the same time)? Once this thing is not driveable, it's not easy for me to get new parts, and mail order is not an option at the moment.

(The final photos are to show where the leak is seemingly *not* coming from, to eliminate some Usual Suspects.)

Thank you.

 

It’s either the hose or the radiator

 

Your last response from your Nov 2025 disappearing coolant thread



Is this the same leak or a different one? Since you couldn’t be bothered to share what you found, I don’t care now. Good luck with the repair

 

WTF? Here we go again, another useless thread.

What difference does it make if you fix one leak, but not the other?

Have you thought about buying a new truck. You don't seem to take sound advice to fix what you got or you just do not have the skills/money to fix it.

Those that are new, check his previous help threads. They tend to go nowhere.

 

Passenger side under radiator leak. I was thinking original radiator but then got to thinking o-ring on the radiator drain valve. $1.99 vs $200.00. As I type this, the test gauge has been holding 15 psi for twenty minutes. Not sign of loose coolant.

O'Reilly's has an assortment of Murray o-rings. MRY 24629 is correct for my 1995 truck.

 

At one point, I thought it might be the drain valve, but it was "closed" so I stopped considering it. But you might be onto something. Can you tell me where this o-ring goes exactly? If the valve is closed, and nothing ia attached to it, where would an o-ring even come into play?

 

It’s on the drain plug, inside the radiator.

 

I don't understand. What is it sealing, if there's nothing connected to the drain plug?

 

Well, it’s sealing coolant from coming out since it’s the drain plug for the radiator.

Pull it out, you’ll see.

 

The valve body is tapered. There is an o-ring on the end of the valve stem. The original o-ring gets hard and flattened and quits sealing as when new. Drain the radiator and then unscrew the valve stem all the way and then yank it out.

I was not losing nearly the amount of coolant you have reported.

 

I really just have no idea what you guys are talking about. Maybe that's the problem - maybe I'm missing some part that should be preventing fluid from coming out?

 

Does this help at all?

 

Yes, thank you! Now I know exactly what to check tomorrow.