Engine Coolant Pressure Test Procedure

[7991LXnSHO]

I have reason to suspect one of my cars is leaking coolant from the intake gasket, just like the horror pictures on here where you can not see it until you pull the manifold. I bought the coolant pressure testing kit - with the adaptors that go between the radiator and cap, and a pressure pump and gauge. But there are no instructions! Rather than make it up, what are the right steps to use my new toy, I mean tool set?

 

[liljoe07]

Use the adapter that fits your set up. Pump up the system to about the caps rated pressure. Then check for the leak. Most testers have separate adapters for the radiator and cap. I've never seen one that goes between the cap and radiator. Which tester do you have?

 

[mikestang63]

You need to get the motor up to operating temp. Slowly remove the cap. Place the test tube into the radiator opening. Fill the tube with teh blue dye and then either squeeze the bulb or if equipped attach the vacuum hose to manifold vacuum that will create a vacuum and you will start to see air bubbles in the dye. You want to make sure that there is a small pocket of air in the top of the radiator so the tube is not sitting in coolant, as that will not allow the gases to come up. When you start to see the bubbles start, then pray the fluid doesn't change color to green. You do not want to put the tube in the overflow container- put it right in the radiator

 

[RangerJoe]

I bet you are using the same cheap kit you can rent at autozone, that's the only kit I have ever used too. I pumped it up to 16 lbs and watched for leaks. Also, watch to see how quickly pressure falls off. I did a Google search since I was loosing 2lbsmof pressure over about 45 minutes time. According to what I found, that was acceptable.

Joe

 

[mikestang63]

oops.. sorry about that.. thought you meant exhaust gas leak tester, not pressure tester. Yeah, get the right radiator cap adaptor, pump it up to lb and let it sit for an hour. Come back every 15 minutes and check for leaks and drop in the gauge.

 

[7991LXnSHO]

Thanks! I will get pics after I get some paperwork caught up. I bought a kit off of Amazon, but the big red case does look familiar. It is a Forgemech 21 piece radiator pressure test kit. Cheap, but the pump and gauge seem better than the Stant brand.

The oil looks great. I still need to inspect the plugs. If it is parked for a few days or more, I get white smoke for a bit and it runs rough at startup while smoking. The longer it is parked, the longer the smoke and rough running. After it is warmed up, it runs great. When run every day, it does not smoke etc.

I also have a mystery fluid that builds up in a dip on the manifold that is right below a bolt that is supposed to be blind and dry. (Was that run on or specific?)

Just in case I can not tell white smoke from black smoke, I backed the electric choke way off and have checked the float levels while parked (via sight plugs in a Holley). It does not seem to be fuel related.

I will post again with results, hopefully before it snows.

 

[stang89bidges]

Don't start talking about snow already. I'm not looking forward to taking my car over to Brady and have him deflate my tires for the cold season just yet...