Running w/ no radiator cap

[ChristopherASA]

Ran up to the nearest food mart yesterday, 20 miles away, and developed a serious leak in the "water tube" that runs front to back (or vice versa) on the right side of the engine. The leak was spewing water. In order to get back home, I removed the radiator cap and drove the 20 miles back home. The leak was a drip, drip, and it ran at it's normal "cool" temperature all the way back home and I calculate it "lost" about 1/2 gallons of coolant. So long as I:

1.) keep coolant in the system, and;
2.) get no indication that the engine is running hot,

what are the dangers until I can get this thing properly fixed?

(Please remember that I live 60 miles from the nearest town, mechanic, parts store, or salvage yard, and that transportation to any of those for any reason is ... difficult, at best.)

[royster]

Hey, Christopher ~
The coolant tube uses "o"rings, so that's likely what you'll need to replace, unless the tube itself is corroded. Your avatar box doesn't indicate what engine you have.

My two cents is that if you keep an eye on the temperature gauge, you'll be alright, but not indefinitely. Should the leak get worse, coolant refills will become more frequent. And certainly, keep plenty of water with you! Good luck!

[LSR Mike]

Pressure cap makes the water boil at a higher temperature. and yes there is an o ring on the front at the waterpump the tube. Hope you are lucky!

[geezer101]

Check that all the mounting bolts holding the external water gallery are all tightly done up. If for some reason they have managed to come loose the pipe will back out of the water pump. Yeah don't run it for long with that kind of leak - an 'O' ring is cheaper than a recon'd head and half an engine tear down...

[ChristopherASA]

I'm sorry. Today I'm being stupid. I should have provided more information. The truck is a 1990 Ram 50 with the 2.4 L engine, "base" model (I can't recall off the top of my head what the engine designation is). The tube that is leaking is on the passenger side of the engine and seems to come out of the water pump, runs to the rear of the engine passing under the exhaust manifold, and then disappears behind the rear of the engine. The leak is just under the rearmost part of the exhaust manifold.

And thanks for taking the time to respond, royster.

[ChristopherASA]

I'm sorry. Today I'm being stupid. I should have provided more information. The truck is a 1990 Ram 50 with the 2.4 L engine, "base" model (I can't recall off the top of my head what the engine designation is). The tube that is leaking is on the passenger side of the engine and seems to come out of the water pump, runs to the rear of the engine passing under the exhaust manifold, and then disappears behind the rear of the engine. The leak is just under the rearmost part of the exhaust manifold.

And thank you for taking the time to reply, LSR Mike!

[ChristopherASA]

Thank you for trying to help, geezer101. I'm sorry. I should have provided more information. The truck is a 1990 Ram 50 with the 2.4 L engine, "base" model (I can't recall off the top of my head what the engine designation is). The tube that is leaking is on the passenger side of the engine and seems to come out of the water pump, runs to the rear of the engine passing under the exhaust manifold, and then disappears behind the rear of the engine. The leak is just under the rearmost part of the exhaust manifold.

[royster]

I can't remember that fitting (my truck is identical to yours') but it seems to me that's where hose clamps on.

Your engine is likely a 4G64.

Try to get back there enough to see. If it's hose, you're somewhat in luck.

[geezer101]

The tube that is leaking is on the passenger side of the engine and seems to come out of the water pump, runs to the rear of the engine passing under the exhaust manifold, and then disappears behind the rear of the engine. The leak is just under the rearmost part of the exhaust manifold.

O.k. I would remove the entire pipe and check for corrosion (it is a long metal pipe approx 5/8" in diameter that is shaped like an 'L' that directs around the back of the block to the heater hoses) The gallery I pulled from my engine was so badly corroded it leaked like a shower head once I'd chemical bathed it and pressure tested the thing. Some of these engines develop leaks in places you won't expect - like the underside of the inlet manifold on the 4G63 carb'd engines. The plenum bases corrode out - it was actually a common problem...

[ChristopherASA]

4G64! Yes! I have such a horrible memory some times. I'm pretty certain it is not a hose but will take a closer "feel" tomorrow. Thanks, royster!

[LSR Mike]

Here's a good look at the Pipe..

18971
18972

[ChristopherASA]

This whole thing (the tube) is seriously corroded. Living where I do (in the middle of the desert), I seriously doubt my ability to get into town and find a replacement in some junk yard. If this tube only goes to the heater hoses, if I don't care about using my heater, any reason I can't just block this thing off right behind the water pump?

Thanks, geezer101

[geezer101]

I'm going to say a tentative 'yes' but I am not sure of the impact it will have on coolant recirculation to the back of the block and head. It may cause a serious hot spot around cylinder #4 combustion chamber which would be disastrous (add the extra stress from heat from where you live). I am going to throw a weird idea at you - get a plumber to braise up a replacement out of copper pipe. Only issue you'll need to figure out is how to get it to seal up against the outlet on the water pump. Theoretically the plumber should be able to make a faithful replica with all the elbows and heater connections close to the right diameter pipe. It will look amazing though :grin:

[LSR Mike]

If the o-ring connection to the waterpump is ok , then yeah, weld/solder/braze that connection onto a new pipe and move on. I will confirm the pipe does supply water to the back of the head after passing thru the heater core.

[geezer101]

I will confirm the pipe does supply water to the back of the head after passing thru the heater core.

I had a feeling that was the case. Last thing I wanted to do was serve up some ill-advised course of action and fry someones' engine. I can confirm the external gallery from a van bolts up the same except one of the heater hose ends faces outward instead of up (might get you out of a bind if you need a pipe and can live without a heater)