Found a bunch of coolant on the garage floor this morning then noticed it was all over the bottom of the shroud and the frame and sway bar.

I at first suspected the lower hose then I noticed it had run down the passenger side of the shroud and I suspected the tank might be leaking. I unbolted it and found no leaks. It was down to about half full.

The truck has shown no signs of overheating. Heater still works fine. No signs of a blown head gasket (steam, hard hoses).

I topped it off and took it for a drive and confirmed it is leaking out the overflow hose. Not constantly and not when you rev the engine.

Only thing that makes sense to me would be a bad cap.

 

Are you speaking of the hose that goes from the radiator to the overflow tank? If so then a leaking hose means exactly that, there is a hole in the hose. Sounds like the cap is doing what it is suppose to. The coolant expands some throughout the cooling system usually because of small air bubbles that just cant get out. Radiator caps are rated for a certain pressure, when the pressure is overcome then fluid is allowed to transfer from the radiator to the overflow, hence the name. If you have coolant spilling out its either because you overfilled the overflow tank or because you have already mentioned you believe the hose is leaking.

 

Nope. The actual overflow tube that dumps out onto the windshield washer tank.

It doesn't appear to be an overpressure situation at all.

A new cap is only $7.99 so I'll give it a shot.

 

Sounds more like the tank is being overfilled, the overflow tube is meant to allow any extra coolant to completely exit the system in the case that its overfilled, where are you filling the tank up to, and are you doing it with the engine completely warmed up or completely cooled off. If you want to replace the cap we cant stop you, but just replacing parts and hoping thats it isnt the way to go about it. If you do decide to get another cap be sure to get a stock pressure, getting a cap with a higher pressure can cause damage to the cooling system especially things like radiators with plastic endtanks

 

Ditto that. If you truly "topped up" the recovery tank, it's now too full. Once the radiator blows some coolant into the tank, it has to overflow somewhere >> out the overflow tube onto the floor. BTW, if you have animals, PLEASE make sure you clean that up!!! It tastes good, and WILL KILL them!

 

Nope. The tank was already a tiny bit low last time I checked it (maybe a pint so I didn't worry with it).

When I saw the coolant on the floor this morning I found the tank to be half empty.

It's obviously lost a bunch over the past week but the truck has shown no signs of overheating or overpressure.

When I say "topped off" I mean I filled the tank back up to the cold fill line while it was graveyard cold.

 

Hmmm. Time to start documenting some stuff. Fill it back up COLD to the cold fill line with the truck on level ground. Check it every day in the same conditions -- "graveyard cold" (I like that term) and refill it as needed (not necessarily every time it's low, but say once a week). Document how much you had to add and how often. Don't know how old your truck is or how many miles. You may be right about the radiator cap... I haven't had to replace one in quite a while. A pressure test shouldn't be too expensive. For that matter, a test kit may cost the same as a pressure test. Keep us posted.

 

Does the coolant system still have pressure on it when it is cool?

 

Some, not a bunch. Just make sure it isn't hot.

 

Update on this: new cap seemed to have solved it. No more puking out the overflow tube anyway.

I do have a very small leak where a radiator tank is crimped onto the core (a problem that pre-existed the spew out the overflow).

I'm keeping an eye on it now.