HELP - LT5 water pump/hose leak

[ZR-1 Black Beauty]

I just replaced my LT5 water pump (bad water seal) and decided to replace the hoses and T'stat also. The system is water tight during operation (about 4 houes run time and 100 miles) and during/after engine cooldown, but in the morning 3+ hours later I find about 1/2 cup of coolant under the car about the water pump position. I have checked all the hoses and areas I can access with the hoses and belt in place; no leak or drips. I suspect the water pump hose connection may be leaking, but cannot confirm this without removing the belt and tensioner.

Any other ideas?

Trying to get this done in order to leave Thur for the NCM ZR-1 Gathering.

Thanks!

[GOLDCYLON]

I just replaced my LT5 water pump (bad water seal) and decided to replace the hoses and T'stat also. The system is water tight during operation (about 4 houes run time and 100 miles) and during/after engine cooldown, but in the morning 3+ hours later I find about 1/2 cup of coolant under the car about the water pump position. I have checked all the hoses and areas I can access with the hoses and belt in place; no leak or drips. I suspect the water pump hose connection may be leaking, but cannot confirm this without removing the belt and tensioner.

Any other ideas?

Trying to get this done in order to leave Thur for the NCM ZR-1 Gathering.

Thanks!

Yep could be the hoses to the pump or crossover pipe as well. You sure the pump is secured tight and you used a clean new gasket?

[QB93Z]

You should be able to borrow a Coolant System Pressure Tester from an auto parts store. Then you can pressurize the system and check that it is tight.

Every time I have worked on the coolant system, a lot of coolant ends up sitting on the horizontal surfaces around the front of the engine. It seems to drip onto the garage floor for a couple of days and then stops.

Jim

[Dynomite]

Get a mirror on a stick with a good flashlight. Whenever I work on coolant systems I always flush with fresh water when done. That way it is much easier to identify new coolant leaks from pools of water that may take a day or two to dry out as Jim suggests.

I also use a bit of Permatex on all coolant gaskets/hoses which helps prevent coolant leaks.

See Use of thread Lubricants, Loctite and Sealants (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp.html#post1580070553)

[Schrade]

You should be able to borrow a Coolant System Pressure Tester from an auto parts store. Then you can pressurize the system and check that it is tight.

Every time I have worked on the coolant system, a lot of coolant ends up sitting on the horizontal surfaces around the front of the engine. It seems to drip onto the garage floor for a couple of days and then stops.

Jim

I had the same problem after top end cleanup.

I ended up getting some wide clamps from JEGS, so I could really screw them TIGHT, without cutting the hose...

http://www.jegs.com/images/mini_100/880-30275-300.jpg

[Dynomite]

I had the same problem after top end cleanup.

I ended up getting some wide clamps from JEGS, so I could really screw them TIGHT, without cutting the hose...

http://www.jegs.com/images/mini_100/880-30275-300.jpg



I use SS Hose Clamps with Rolled Edges (http://jerrysgaskets.com/store2/root/index.php?main_page=product_info&cPath=5&products_id=826) from Jerry's on ALL Coolant Hoses.

http://jerrysgaskets.com/store2/root/images/10108255-SS.jpg

[ZR-1 Black Beauty]

Thanks everyone for the advice.

I used a new gasket, cleaned all the surfaces and torqued the bolts to specs. I also used Jerry's hoses and new clamps. Didn't want to leave much to chance.

My surprise is the system is tight during running operating and for a couple of hours after shutdown, but leaks several hours later. I will check the underside of the engine again with a mirror and flashlight.

If the system is tight during operation will a pressure check find any issues? May be worth a quick try.

Thanks again.

I just replaced my LT5 water pump (bad water seal) and decided to replace the hoses and T'stat also. The system is water tight during operation (about 4 houes run time and 100 miles) and during/after engine cooldown, but in the morning 3+ hours later I find about 1/2 cup of coolant under the car about the water pump position. I have checked all the hoses and areas I can access with the hoses and belt in place; no leak or drips. I suspect the water pump hose connection may be leaking, but cannot confirm this without removing the belt and tensioner.

Any other ideas?

Trying to get this done in order to leave Thur for the NCM ZR-1 Gathering.

Thanks!