Leakdown test/finding TDC

[PromiseKeeper]

I want to do a leakdown test on my 1980 C-10 with a 305. Could someone lend some advice on how to get each cylinder to top dead center to test them? Everything I've read so far tells me that's what I need to do, but doesn't tell me how to do it! I see Summit has a tool to put in the plug hole. Is it worth buying? Thanks in advance!

Scott

[rsandusky]

Line up the mark on the harmonic balancer to 0, compression stroke of cylinder #1 and you will be at Top Dead Center. Every 90 degrees clockwise of crankshaft rotation you will be at TDC of a cylinder in the firing order.

What problems are you having that you want to do a leak down test?

[PromiseKeeper]

It is using some oil and I'm seeing some smoke at idle that is blue and smells like oil. What I'm looking for is to find out if it is rings or valve seals. I don't want to just start throwing money at it if it isnt needed. Thanks for the reply!

[bake74]

     A compression check of each cylinder can determine most of those also, you have to do a dry check on each cylinder, then redo with a couple of drops of oil in each cylinder.  If you have a chilton manual it goes through the steps and how to check for leaky rings, valves bypassing, head gasket and so on.