I am changing head gaskets now. Should I do a pressure test on the cooling system before I completly assemble the engine? If I should what is a good tester to buy? Still waiting for parts and the machine shop.

Thank you,
Willie

 

What year is the truck. Why I ask is DI fills just by pouring in the coolant. A DII is the whole air in the system thing. So if it's a DII buy a vacuum system filler. It won't tell you where the leak is but it will let you know you have one before you fill it. Plus when you fill it you wont have any air in the system. Even if you pressure test the system with no fluid in it you wont see a leak either. The only thing is you need a compressor to use the vacuum filler.

 

It is a 2000 DII. That is a good idea to use a vacuum tester. Who makes a tool like that? I do have a compressor.

Willie

 

The big tool guys like snap-on and mac have em. But there are a bunch of other ones out also. Just watch ya get what ya pay for sometimes. I have the snap-on one but I use it all the time. There are some pretty good name brands that make em too so you should be able to find a good one for less.

When you use it and it sucks down the system. turn the valve off and watch the gauge. if it moves, make sure the fit to the reservoir is good and if thats ok then you have a leak somewhere. It shouldn't move at all.

 

It puts the coolant in too.

 

I have a electic vacuum pump that might work if I hook up a gauge and valve.

Willie

 

Thats not really the way those work. Besides it fills the system too. Look into it before you try to make something. The time you spend doing that might be worth just buying one.