what does cylinder leak down mean? and how does that happen?

 

It's just compressed air is fed into a cylinder, and the amount of time it takes for the pressure to subside is measured, can give a lot better indication of some conditions than a std compy test.
tabetha

 

mine got 50% leak down on 2,3,and4 cylinder!

 

The great thing about doing a leak down test is you can pin point the fault ie rings, inlet/exhaust valves or headgasket with out dismantling the engine...unlike a standard compression test that basicaly just tells you its down.

 

what tool do you use to do this test as i would like to do mine???

 

Mines a proper snap-on set up with a gauge. You can buy cheap versions that do exactly the same for around 30-40quid......but tbh you can make one also. Get an airline adaptor, a old spark plug and a peice of metal pipe. Smash the plug electrode out so you've just got a threaded part with a hole straight through. Weld the metal pipe to this then weld the airline adaptor on the end....just so you can fill the cylinder with compressed air. Set the piston at tdc on the compression stroke, leave it in gear with the handbrake on and hook up the air line to the fitted adaptor. You wont have a gauge but you can listen/look for the leaks. Oil filler cap off or dip stick out to gauge ring blow-by, ear to exhaust tail pipe to listen for a leaky ex valve, ear to inlet for inlet valve and Ive even managed to find a headgasket failure in the past by air bubble's in the header tank.

 

is this the gauge to use???

http://buy1.snapon.com/products/diag...s/eepv309a.asp

 

Nothing like mine but yeah, thats what your after.

 

Just looked on ebay and the cheapies are around Ł60....I think I must have sold my old spare one for around Ł30, hence where I got that price from in my head.

There's this one....

http://cgi.ebay.co.uk/Sykes-Pickavan...3A1%7C294%3A50

 

cheers for that!!!

 

i made one using the above method, apart from i tapped a 1/4 bsp thread into the remains of the spark plug and wound in a barrel nipple and make some adapters up to take an air line. worked perfectly for me, one completely fooked head