2000 Silverado Coolant Leak

[endlesswinter]

My 2000 Silverado 5.3L occasionally is low on coolant (about once every 200 miles). It leaks randomly, sometimes when the motor is running, other times after the motor is shut down. I have seen a drip coming from the reservoir and coolant hoses area but have not isolated it yet. I have checked all of my lines and fittings and have found no cracks or other sources of a leak. A friend told me it could be a faulty of cracked water pump housing. Does this sound familiar with Silverados?

[MT-2500]

You need to spot the leak.
Have a look around and under everything.
Look under water pump and check rad area.
Check all heater and rad hoses.
Check inside cab carpet.
Check front and rear intake area.
Check under engine area for coolant.
And make sure no coolant in the engine oil.
Check rad cap and overflow coolant tank and hose for leakage.

The also make a leak dye kit for the hard to find leaks.

Pressure test coolant system cold and warm and then hot.

Post back if you see any leaks.

[endlesswinter]

Thanks a lot!

[j cAT]

Originally Posted by endlesswinter

My 2000 Silverado 5.3L occasionally is low on coolant (about once every 200 miles). It leaks randomly, sometimes when the motor is running, other times after the motor is shut down. I have seen a drip coming from the reservoir and coolant hoses area but have not isolated it yet. I have checked all of my lines and fittings and have found no cracks or other sources of a leak. A friend told me it could be a faulty of cracked water pump housing. Does this sound familiar with Silverados?

adding coolant every 200 mi is excessive. the res is at 15psi so any leaks in this area could be the sole cause ...these hoses are easy to inspect...prior to starting when cold look for stains and coolant at the hose fasteners...could also be the res has a crack..its easy to remove...when cold fill to the add cold mark..when checking use a white paper towel ...

what type coolant do you use ...and how often do you service the antifreeze[replace]....the water pump leaking would not cause coolant around the res...area...

[777stickman]

1. deleted!!
2. The most common coolant leaks are the intake manifold gaskets.
3. I have not seen posts about cracked or broken water pump housings though it's posible. If the pump's leaking it's most likely the shaft seal and it will leak out of the "weep" hole.

As MT-2500 said you really need to locate the source of the leak. Look real close around the intake to heads. Pull the spark plugs and check them for possible coolant contamination (coolant leaking into the combustion chambers).

[j cAT]

Originally Posted by 777stickman

1. The coolant recovery tank is not under pressure.
2. The most common coolant leaks are the intake manifold gaskets.
3. I have not seen posts about cracked or broken water pump housings though it's posible. If the pump's leaking it's most likely the shaft seal and it will leak out of the "weep" hole.

As MT-2500 said you really need to locate the source of the leak. Look real close around the intake to heads. Pull the spark plugs and check them for possible coolant contamination (coolant leaking into the combustion chambers).

sir I suggest you recheck your source on this info that I supplied ....as you know I own 2000 5.3L silverado.... and the res bottle is at 15 psi when at operating temp... the little hoses may have a problem ,,,,

[rockwood84]

yep the cat is right the radiator has no cap the cap is on the resevoir. when filling the radiator the coolant must go in the resevoir can't pour it in the radiator.

[777stickman]

j cAT & rockwood84: Thanks for the notes. Makes me remember to stay away from the Y2K's and newer models. My original post has been edited.

Keep up the great posts to you both............777stickman

[wafrederick]

Could be the water pump gaskets also and most parts stores stock them.Seen one van do this with a 5.3 and it was the water pump gaskets.Put a pressure pump on it to find the leak.

[calratliff]

My '03 did the same thing. It turned out to be the water pump seal. It is an o-ring rather than a typical gasket. The reason for the intermittent leaking is the "dexcool" coolant has a leak stopping agent. So it would leak --- then seal off --- then leak again. Had 100,000 miles so I went ahead and replaced the pump instead of just changing the o-ring.