leak down test

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syty9933

New member
i just got my leak down test kit in today ,and had some questions:

How do i move the cylinders to tdc?

how important is a listening tool or what should i use for one?

The instructions say that all engines will have somewhat of a loss of compression past the rings that is audible through the dipstick, and if thats true how am i supposed to verify ring compression loss if that is the case?
 
JSM

JSM

Active member
Re: leak down test

Leak down will give you a % reading after test. Rotate each cylinder using the front crank bolt by HAND. If you put the line in the spark plug and put finger over the end you will feel the air go out as it comes up, then stop as it gets to TDC. Apply air and hope motor doesn't spin forward or back, if it does take note and rotate it more/less from where you were before. If you have a 360 deg marked balancer it makes it a lot easier.

Once you get cylinder pressurized you can feel the dip stick tube, intake, or exhaust for where leak is coming out if you find a bad cylinder. Takes some practice but you will catch on its not rocket science. Hardest part is getting each cylinder to TDC.
 
BoostedSUV

BoostedSUV

Active member
Re: leak down test

Make you sure set the regulator on the leak tester properly before you do any testing. Set it to the 100 percent mark therefore you will have an accurate leakage reading.

I just threaded the hose into the cylinder and cranked the motor by hand until I felt air coming out of the hose. Keep turnig it slowly just until the air stops compressing out and hook up the leakdown tester with the compressor air up to the hose. I put a rachet onto the ALT bolt to hold the motor from turning. The compressor air will push the piston down if you don't.
 
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syty9933

New member
Re: leak down test

i have everything hooked up but cant get tdc, cant turn the crank or even get to it, and if blown may just get rid of it because i cant stand thowing more money and time at somthing that is just shooting me in the face everytime!
 
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syty9933

New member
Re: leak down test

it helped but i still dont know how to put it at top dead center, and i dont feel like taking any more parts off than i have to
 
The_Bronze

The_Bronze

Donating Member
Re: leak down test

You can these old school methods as well:

Pull the plug. Insert a straw (bent at the end that you hold) or wide zip-tie into the hole (don't let go of the other end. I put a couple zip ties together to prevent that from happening) and turn the motor over until the indicatator (straw or zip-tie) is at the highest point. Go past a bit and then back until you are confident that it is close, since it isn't easy to identify the exact TDC. If it's close, the valves are closed and you can get a good reading. If you hear air coming from the exhaust or intake, you can rotate the motor a bit back and forth to ensure you have it closed. You might have to pull the upper radiator shroud to get access to the crank center bolt though (I haven't even had mine together yet so your access might vary. I use a breaker bar to hold it while applying the air to the cylinder so that it piston doesn't fall back.

You can insert the leak checker hose into the cylinder and install a small balloon to the hose end as well, As you bring the piston up, it usually fills the balloon and you can see when it starts to fall. Back it off a bit and you are good. This method sometimes works, but if you have too wear on your rings/cylinder it may not. Just some methods to try if the other ways are too complicated or confusing.
 
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syty9933

New member
Re: leak down test

i have no idea how to turn the crank to tdc for each cylinder can someone give me a step by step?
 
BoostedSUV

BoostedSUV

Active member
Re: leak down test

syty9933 said:
i have no idea how to turn the crank to tdc for each cylinder can someone give me a step by step?
Click to expand...

Use a breaker bar with a 5/8 socket and put it on the crank bolt in the crank pulley. Turn it until you feel air coming out of the leak down tester hose. Its best to have the valve covers off so you can see that both valves are closed. If you have all 6 plugs out you can turn the motor by the alt pulley nut if the belt is still on... Hth
 
BoostedSUV

BoostedSUV

Active member
Re: leak down test

Normally I would come on here and tell Dave he's being a little harsh with a beginner and to lighten up, but this time I won't. Dude I've read so many of your posts and PM's and you are constantly asking the same questions, and getting great answers. Then you'll start a new thread asking the same questions all over again. I would hate to see you give up but dude you have to start listening to the people on here. You can't afford to pay someone to fix it for you so if you are going to ask for help learning please listen. What you are trying to do is not rocket science... I would hate to say it but you're in over your head with a syclone and the lack of general engine logic you have. There's nothing that can't be learned, you just have to be patient and listen to the guys on here that have done this before... The problem is people are starting to realize they are wasting their time helping you because you won't listen and ask somebody or start another thread trying to get different answers because I guess you don't like the ones you got??? I'm extremely patient with learning curves and I have spent a lot of time trying to guide you when others gave up... If you're not going to listen you're on your own. Free help is hard to come by, if you don't want to listen take it to a shop and pay $85 an hour for an "expert" to do it for you...
 
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syty9933

New member
Re: leak down test

BoostedSUV said:
Normally I would come on here and tell Dave he's being a little harsh with a beginner and to lighten up, but this time I won't. Dude I've read so many of your posts and PM's and you are constantly asking the same questions, and getting great answers. Then you'll start a new thread asking the same questions all over again. I would hate to see you give up but dude you have to start listening to the people on here. You can't afford to pay someone to fix it for you so if you are going to ask for help learning please listen. What you are trying to do is not rocket science... I would hate to say it but you're in over your head with a syclone and the lack of general engine logic you have. There's nothing that can't be learned, you just have to be patient and listen to the guys on here that have done this before... The problem is people are starting to realize they are wasting their time helping you because you won't listen and ask somebody or start another thread trying to get different answers because I guess you don't like the ones you got??? I'm extremely patient with learning curves and I have spent a lot of time trying to guide you when others gave up... If you're not going to listen you're on your own. Free help is hard to come by, if you don't want to listen take it to a shop and pay $85 an hour for an "expert" to do it for you...
Click to expand...


i understand exactly what you mean, i really do aprecciate the help and this should be the last thread dealing with the same topic. I already got the answers and im sorry for the inconveinces and thank you again for all the great help
 
BoostedSUV

BoostedSUV

Active member
Re: leak down test

Crank the motor by hand until the rotor points to the ignition wire of the cylinder you want to check. This will verify TDC of that particular cyl and that you are on the compression stroke.
 
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syty9933

New member
Re: leak down test

BoostedSUV said:
Crank the motor by hand until the rotor points to the ignition wire of the cylinder you want to check. This will verify TDC of that particular cyl and that you are on the compression stroke.
Click to expand...

thanks i have everything i need now
 
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