91 Dodge Ram coolant leak question

[episodic]

Cant see exactly where it is coming from. Not the radiator. Somewhere on the bottom front of the engine. Funny thing is it only leaks when the truck is cool. It doesn't leak at all on a warm pressurized system. I reallllly don't want to invest money into this truck. Is stop leak likely to work. The leak is significant. . .

I can fill it up and start it and run it for 30 minutes - no leak. Drive it down the road. No leak. Turn off the engine and walk away - an hour later - drip drip drip

 

[ja1484]

If it leaks on a cold engine, get in there and dig out the problem. It's probably a $5 hose, clamp, or seal somewhere.

 

[episodic]

I've checked the hoses. If it is a seal - which should I be looking at? It is wet everywhere. I'm scared it is a 'seal' as those are really pricey to replace - especially with it leaking from the front bottom of the engine.

 

[ja1484]

Originally posted by: episodic
I've checked the hoses. If it is a seal - which should I be looking at? It is wet everywhere. I'm scared it is a 'seal' as those are really pricey to replace - especially with it leaking from the front bottom of the engine.

Not always...but sometimes.

Step 1 is clean everything the hell up in there and then watch for the issue to form over time...look for fluid stains on parts...gotta trace it to the source.

If you're sure it's coolant, I'd obviously start at the radiator, hoses, and coolant reservoir.

If you *think* it's coolant, first identify the fluid. If you are unsure of your ability to do *that*, you should probably make peace with your Visa and just take it to the shop.

 

[episodic]

I'm sure it is coolant. I've went through several coolant jugs full of water. . .

I just have to fill it with a jug of water before I go anywhere. . .

Yea, make peace. . . yea. . .

 

[LTC8K6]

Water pump weep hole?

 

[exdeath]

Originally posted by: LTC8K6
Water pump weep hole?

This.

 

[radioouman]

It is the water pump. It DOES leak while you are driving it, but the engine is hot enough that the coolant evaporates. You can smell it even if you can't see it.

Not a huge deal on your truck. Does it have a 318? If so, remove the fan shroud and the fan. Drain the coolant. If the stop cock is stuck, disconnect the lower radiator hose from the radiator to drain. Disconnect the upper radiator hose from the thermostat housing. Might as well remove the housing and get a new thermostat and gasket. Remove the serpentine belt. Remove the A/C compressor and put it off to the side. (Obviously don't take the hoses lose.) Take off the alternator and put it off to the side. (You can leave the wires attached.) Remove the bolts that hold the aluminum bracket on for the alternator and A/C compressor. Remove the aluminum bracket.

The waterpump is now visible and there is a tube sticking out of it on the driver's side where one of the heater hoses clamps on. You will need to pull this tube out of the waterpump and save it for the replacement. It is stuck in there with a rubber o-ring. Make sure you leave it mounted on the engine while you pull out this tube.

Now disconnect the hoses going to the waterpump. As you can see, there is a small hose that goes from the top of the waterpump to the intake manifold. You will want to replace this hose since it is tough to get to. Remove all of the bolts holding the waterpump to the engine. Remove the waterpump. It may be stuck if it is a very old gasket.

Get a new waterpump and gasket. Make sure that all of the old gasket material is off the engine. If you've never replaced the timing chain, this is the time to do it. To do that, you need to drain the oil, use a harmonic balancer puller to pull the harmonic balancer off, remove the crankshaft bolt, remove the crank pulley, remove the timing chain cover, install a new timing chain paying attention to the timing marks on the new gear/chain set and the position on the timing shafts, then install a new timing chain cover gasket.

Now, install the new waterpump and gasket, re-attach the hoses, reinstall the aluminum ac compressor and alternator bracket, install the fan, fan shroud, and serpentine belt. Refill the cooling system through the radiator, and if you change the timing chain, refill the engine with oil.

 

[boomerang]

Originally posted by: radioouman
It is the water pump. It DOES leak while you are driving it, but the engine is hot enough that the coolant evaporates. You can smell it even if you can't see it.

Not a huge deal on your truck. Does it have a 318? If so, remove the fan shroud and the fan. Drain the coolant. If the stop cock is stuck, disconnect the lower radiator hose from the radiator to drain. Disconnect the upper radiator hose from the thermostat housing. Might as well remove the housing and get a new thermostat and gasket. Remove the serpentine belt. Remove the A/C compressor and put it off to the side. (Obviously don't take the hoses lose.) Take off the alternator and put it off to the side. (You can leave the wires attached.) Remove the bolts that hold the aluminum bracket on for the alternator and A/C compressor. Remove the aluminum bracket.

The waterpump is now visible and there is a tube sticking out of it on the driver's side where one of the heater hoses clamps on. You will need to pull this tube out of the waterpump and save it for the replacement. It is stuck in there with a rubber o-ring. Make sure you leave it mounted on the engine while you pull out this tube.

Now disconnect the hoses going to the waterpump. As you can see, there is a small hose that goes from the top of the waterpump to the intake manifold. You will want to replace this hose since it is tough to get to. Remove all of the bolts holding the waterpump to the engine. Remove the waterpump. It may be stuck if it is a very old gasket.

Get a new waterpump and gasket. Make sure that all of the old gasket material is off the engine. If you've never replaced the timing chain, this is the time to do it. To do that, you need to drain the oil, use a harmonic balancer puller to pull the harmonic balancer off, remove the crankshaft bolt, remove the crank pulley, remove the timing chain cover, install a new timing chain paying attention to the timing marks on the new gear/chain set and the position on the timing shafts, then install a new timing chain cover gasket.

Now, install the new waterpump and gasket, re-attach the hoses, reinstall the aluminum ac compressor and alternator bracket, install the fan, fan shroud, and serpentine belt. Refill the cooling system through the radiator, and if you change the timing chain, refill the engine with oil.

You can't beat step-by-step instructions. I'll add that it's a great time to replace the rest of the hoses too if needed.

It may be that bypass hose running from the water pump to the manifold that's leaking. They're buried, it's real hot in that area and they're usually the first to go.