Gary Lewis Posted July 30, 2018 Share Posted July 30, 2018 I'm struggling with find tdc on the compression stroke without compression. Its the rear cylinder which is too tight to insert something. Can I use the rockers position to find it? Yes, but should be able to use the rotor on the dizzy to tell. Trace the plug wire to the cap, note the position, pull the cap and turn the engine until the rotor is pointing at that position. Link to comment Share on other sites More sharing options...
85lebaront2 Posted July 30, 2018 Share Posted July 30, 2018 Yes, but should be able to use the rotor on the dizzy to tell. Trace the plug wire to the cap, note the position, pull the cap and turn the engine until the rotor is pointing at that position. Find TDC #1 on the balancer, rotor pointing back. rotate the crank 180° clockwise and you will be on #4 TDC (firing order 15426378). Link to comment Share on other sites More sharing options...
Tallyho Posted July 30, 2018 Author Share Posted July 30, 2018 Find TDC #1 on the balancer, rotor pointing back. rotate the crank 180° clockwise and you will be on #4 TDC (firing order 15426378). I got it using the rotor. Brilliant idea by the way Gary! I was really struggling trying to get my air chuck to stop leaking when I noticed the furthermost spring kinda looked clocked a bit. I spun the spring around and sure enough its broken Link to comment Share on other sites More sharing options...
85lebaront2 Posted July 30, 2018 Share Posted July 30, 2018 I got it using the rotor. Brilliant idea by the way Gary! I was really struggling trying to get my air chuck to stop leaking when I noticed the furthermost spring kinda looked clocked a bit. I spun the spring around and sure enough its broken At least you found it! I had a similar problem with my son's 1965 Corvair Corsa, at least that one was easy to change, just had to be underneath to do it. Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 30, 2018 Share Posted July 30, 2018 I got it using the rotor. Brilliant idea by the way Gary! I was really struggling trying to get my air chuck to stop leaking when I noticed the furthermost spring kinda looked clocked a bit. I spun the spring around and sure enough its broken If you can get the valve to seat by pulling up while you have air pressure on it then it should seat and stay. Then you can pull the keeper, get the spring off, put the new spring on, and replace the keeper. Link to comment Share on other sites More sharing options...
Tallyho Posted July 30, 2018 Author Share Posted July 30, 2018 If you can get the valve to seat by pulling up while you have air pressure on it then it should seat and stay. Then you can pull the keeper, get the spring off, put the new spring on, and replace the keeper. Thanks, I've never replaced a valve spring before. Are there any special tools required? Once I found tdc on that piston the cylinder was going up in pressure. I had it at 40 psi when I was fiddling trying to get the air chuck to stop leaking. I'm sure it could go more. It looks like there's a chance I might get lucky wish this fiasco. What are common causes of spring failure? If a new spring fixes this should I replace them all? Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 30, 2018 Share Posted July 30, 2018 Thanks, I've never replaced a valve spring before. Are there any special tools required? Once I found tdc on that piston the cylinder was going up in pressure. I had it at 40 psi when I was fiddling trying to get the air chuck to stop leaking. I'm sure it could go more. It looks like there's a chance I might get lucky wish this fiasco. What are common causes of spring failure? If a new spring fixes this should I replace them all? I suspect it is just a flaw in the spring, but I’ve not had one break so I don’t know. Anyway, I don’t think you need to replace them all. As for tools, it takes a valve spring compressor. You may be able to rent/borrow one at your local parts store, but if not you may want to take the truck to a shop to have it done. That way you don’t have to buy the spring compressor. Link to comment Share on other sites More sharing options...
85lebaront2 Posted July 30, 2018 Share Posted July 30, 2018 I suspect it is just a flaw in the spring, but I’ve not had one break so I don’t know. Anyway, I don’t think you need to replace them all. As for tools, it takes a valve spring compressor. You may be able to rent/borrow one at your local parts store, but if not you may want to take the truck to a shop to have it done. That way you don’t have to buy the spring compressor. If you can borrow or rent one that hooks under the spring and pushes down on the retainer, it will work quite well. Use a small magnet to retrieve the keepers. Take everything off and unload the broken spring, put the new one in the tool and compress it until it will go over the stem far enough to put the keepers in (use a dab of grease to help hold them). I usually pull the spring and retainer up against the keepers so the won't slip while I release the pressure. Link to comment Share on other sites More sharing options...
Tallyho Posted July 31, 2018 Author Share Posted July 31, 2018 If you can borrow or rent one that hooks under the spring and pushes down on the retainer, it will work quite well. Use a small magnet to retrieve the keepers. Take everything off and unload the broken spring, put the new one in the tool and compress it until it will go over the stem far enough to put the keepers in (use a dab of grease to help hold them). I usually pull the spring and retainer up against the keepers so the won't slip while I release the pressure. Thanks for that. I'm trying to decide if I should use my pancake compressor or use rope to hold the valve. Right now with the piston at tdc the compressor will fill the cylinder. When I release the little tension I have on the valve will the pancake be enough? Or do I need a compressor with more volume? Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 31, 2018 Share Posted July 31, 2018 Thanks for that. I'm trying to decide if I should use my pancake compressor or use rope to hold the valve. Right now with the piston at tdc the compressor will fill the cylinder. When I release the little tension I have on the valve will the pancake be enough? Or do I need a compressor with more volume? What kind of pressure is the compressor holding in the cylinder? And, how often does it have to run? If you are able to keep something like 100 psi in the cylinder then the size of the compressor, or I should say the volume of the compressor, doesn't matter. The pressure is what holds the valve in place, and if yours will do it then a bigger compressor wouldn't make any difference. Where a bigger compressor would help is if your compressor is having to run continuously to keep the cylinder filled. A bigger compressor would have enough volume to be able to handle the leakage you have without running as long or often as yours. But if yours isn't having to run a lot then a bigger one won't help. Link to comment Share on other sites More sharing options...
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