Can't hold Vacuum in cooling system

[NewArt]

I have my suspicions on mine as well but it's difficult to discern the actual culprit. I'm doing a leak down test tomorrow to see if there's some other problem but I get the feeling there's something not right up top.
The o-rings on the bleeder valve can be changed but that shouldn't be necessary on a new or recent tank. How to test it? No idea.

[JFP in PA]

Originally Posted by NewArt

I have my suspicions on mine as well but it's difficult to discern the actual culprit. I'm doing a leak down test tomorrow to see if there's some other problem but I get the feeling there's something not right up top.
The o-rings on the bleeder valve can be changed but that shouldn't be necessary on a new or recent tank. How to test it? No idea.

If you think the tank or bleeder are leaking, use a system pressure tester to pressurize the system and then coat the bleeder area with a soapy water mix; if it is leaking, you will get a ton of bubbles.

[redeye280z]

I finally did a few more tests today and found that the bleeder valve was leaking. I took it apart and compared it to the one from my tank that was cracked and was surprised to find that the prints were too thin to make a good seal. I had to run to the local auto parts to find some new o rings. I finally put it all back did the test and it held the vacuum so I refilled the system. Now my temperature light won't stop flashing. The tank is a little over filled right now is it possible that the light would flash if you overfill? What could the cause be the sensor was fine in the old tank.

[JFP in PA]

Originally Posted by redeye280z

I finally did a few more tests today and found that the bleeder valve was leaking. I took it apart and compared it to the one from my tank that was cracked and was surprised to find that the prints were too thin to make a good seal. I had to run to the local auto parts to find some new o rings. I finally put it all back did the test and it held the vacuum so I refilled the system. Now my temperature light won't stop flashing. The tank is a little over filled right now is it possible that the light would flash if you overfill? What could the cause be the sensor was fine in the old tank.

Four functions of the coolant warning light:

1. Engine coolant level too low
— light flashes slowly (0.5 Hz)
2. Engine compartment temperature too high
— light flashes slowly (0.5 Hz) (engine compartment blower might be faulty)
3. Engine coolant temperature too high
— light is lit; pointer on the right
4. Temperature sensor at water outlet faulty
— light flashes rapidly (1 Hz); pointer on the right

Note
The temperature warning in point three is indicated if the conditions "engine coolant temperature too high" and "engine coolant level too low" are present simultaneously
(1Hz = 1 flash per second. 0.5Hz = 2 seconds per flash)

[redeye280z]

The light started flashing immediately after I started the car. The level of coolant was top up to the max line and the engine was still cold. The sensor was fine when I took it from the old tank. Is there any way to test the sensor to see if it is working properly. Also as a note when I disconnect the harness from the plug it still flashes I was under the impressing that unplugging it would stop the light from blinking. Logically it has to be something with the sensor since I have just finished removing all these parts and putting them back.

[JFP in PA]

Originally Posted by redeye280z

The light started flashing immediately after I started the car. The level of coolant was top up to the max line and the engine was still cold. The sensor was fine when I took it from the old tank. Is there any way to test the sensor to see if it is working properly. Also as a note when I disconnect the harness from the plug it still flashes I was under the impressing that unplugging it would stop the light from blinking. Logically it has to be something with the sensor since I have just finished removing all these parts and putting them back.

Have you tried timing the flash and comparing that to the data above?

[redeye280z]

It's a slow flash. I am almost quite certain that maybe the coolant level sensor went bad in the transfer. I was just wondering is there a way of testing it?