sloooowwly losing coolant

[Chuck_in_WI]

I noticed this past fall that I am ever so slowly losing coolant. I never saw a puddle under the car until yesterday. I was in a hurry so I could not investigate further. Any ideas of where to look further? It did not appear to be under the radiator, but further back. It does not leak all the time, maybe only when it's warmed up?? The oil fillcap is not milky looking.

What else can be wrong? I am putting the car away for the winter very soon and would rather deal with the issue in spring but would kinda like to know now what it might be. Just so that I have more to worry about for 5 months.

TIA

Chuck

[BillWilliams]

You are just going to have to drive it and then get it safely in the air and with a good flashlight, take a look around. Water can run anywhere with ease. So do not rule out the water pump or a leak from one of your hoses.

As you probably know, the water pump wants to leak from a weep hole in the bottom of the pump. Check really good there. There is also a bolt in the passenger side of the motor used to drain the block, check that too.

If the front of the motor is dry, start looking around your freeze plugs and if that is not it, I will let others tell you about the bad places to check.

[Mike Self]

A weeping water pump is hard to diagnose, because coolant dribbles out the weep hole (at six o'clock under the fan & pulley) which is hard to spot in the first place, then is immediately evaporated by engine heat and the fan blowing it around. Water pump leaks usually occur only when the engine is running, making 'em harder to spot.

Three ways to check:

1. If you have access to a pressure tester, pressurize the system and watch the weep hole. See if it dribbles engine off.

2. look for whitish deposits around the weep hole--best way to look is to lay down under the car and look straight up between radiator and engine--use a strong light to illuminate the area. If youre careful, you can do this while the engine is running--warmed up with a fully pressurized system--and you may be able to catch it in the act.

3. grab the fan (engine off of course!) at a blade end and try to rock it axially. If it wiggles, the bearings are going, and the loose bearings have chewed up the shaft seal.

happy troubleshooting

mike

[jgerry2002]

Check the heater hoses, and check the hoses that run from the block to the manifold (assuming you have carb'd car), my '76 has a small leak from this spot.

[colorobo2002]

It could be leaking in your heater box or valve. Does it smell like coolant if you crank up the heat and fan? Check around the heaterbox under your dash.

[Tiger75]

It is a littte pump that has a radiator cap on the end. You can pressure up on your cooling system when it is cold and look for leaks. There is also a water based dye that can be addded to coolant. You use a floresent light to see where it drips out.

[John_in_VA]

Stant makes radiator caps, etc.

From the location of the puddle it points to the water pump, but a look will tell.

[SteveJ]

Get yourself a Stant ST-270 pressure tester.

Great tool. In addition to finding leaks (like when a hose clamp has loosened up), there are some other tests you can do with this tester to see if you have a combustion leak into the cooling system.

They pop up on ebay pretty often, or can be had new at www.toolwarehouse.net

[Napes]

I too, think the location of the puddle indicates a bad H²O pump. If the suggestions from Mike Self (above) indicate that's the problem, then, at least, new pumps are relatively inexpensive and the R & R process is straightforward.

Bob Napier

[Chuck_in_WI]

thanks for all the suggestions. Will look soon. How much $ is a new h20 pump and where are they available?

Chuck