Bleed lifters?

[Jeepman85]

Hey there. Have an 85 CJ7 , AMC 258 i6 / 4.2l , stock AMC 258 i6 / 4.2l head. I had to do a valve job and am getting ready to put this thing back together (using the same cam, lifters, push-rods, rockers). I have been told that once the rockers have been torqued, there is no other adjustments to be done. I have also been told that the lifters must be bled so a valve doesnt get stuck open and leave me with no compression. Searching some other forums i read that the lifters will automatically go to where they need to be once the rockers are torqued!? Which is it? Any suggestions are appreciated!

 

[IOPort51]

bleeding lifters is a new one on me.

 

[BusaDave9]

Me neither, I never heard of the need to bleed lifters but here is a link saying how to:
HOW TO: Bleed Your Lifters - evolutionm.net

 

[Kane]

Since you are putting your head back on and your entire valve train is basically dry it is a good idea to reprime your oil pump and get the oil back up through the push rods and on the rocker arms. When every rocker is getting visable oil then your lifter are bled. The oil passes through the lifter and up the push rod to the rockers.

In a new motor the lifters are empty and when you are trying to start the motor for the first time this will have a tendency to only open your valves half way and you will never get enough compression to start the motor. I think that is what people are referring to when they tell you to bleed the lifters. A lot of people soak their lifters in oil before installation to help with the priming process. I have seen motors not start because of lifter that are not properly primed.

 

[IOPort51]

I think this would be priming the lifters.

Since you are putting your head back on and your entire valve train is basically dry it is a good idea to reprime your oil pump and get the oil back up through the push rods and on the rocker arms. When every rocker is getting visable oil then your lifter are bled. The oil passes through the lifter and up the push rod to the rockers.

In a new motor the lifters are empty and when you are trying to start the motor for the first time this will have a tendency to only open your valves half way and you will never get enough compression to start the motor. I think that is what people are referring to when they tell you to bleed the lifters. A lot of people soak their lifters in oil before installation to help with the priming process. I have seen motors not start because of lifter that are not properly primed.

 

[Cheepjeep85]

i've always just soaked them in oil before putting them in, then use an oil pump primer to get oil through the motor before starting it. nobody else has said anything but if you could swing it you really should use a new cam and lifters, it would suck to get it back together and have a old lifter collapse and start tickin. you only need to torque the rocker arms down to 19-20 ft lbs.

 

[dalefan88]

i've always just soaked them in oil before putting them in, then use an oil pump primer to get oil through the motor before starting it. nobody else has said anything but if you could swing it you really should use a new cam and lifters, it would suck to get it back together and have a old lifter collapse and start tickin. you only need to torque the rocker arms down to 19-20 ft lbs.

ive always done the same. soaked then in oil.

 

[IOPort51]

one other trick is to remove the handle from a large flatblade screw driver, put it in a drill motor and use it to turn the oil pump before installing the distributer. this primes everything with out turning the motor over.

 

[BusaDave9]

IOPort has a good idea for priming the engine and I agree with the rest of you: soaking the lifters should be good enough but I have seen several links regarding bleeding the lifters with a paper clip or small allen wrench. (Check out the link I posted above) Most of these links are regarding newer engines with overhead cams. I don't know if "bleeding" your lifters is necessary on a jeep engine. Priming should be good enough.

 

[Cheepjeep85]

yep but a better way is to make an oil pump primer out of an old dist. this way all of the oil galleys that would normally be blocked by the dist. and allow oil to flow normally up to the top end, do their job. plus using a screw driver in a drill isn't very stable, you really don't want to let that oil pump shaft wobble around to much. oh and when you prime a motor you need to get a friend to turn it over by hand, a quarter turn at a time every so often, and keep on priming till you get good oil flowing out of all of the rockers.

 

[IOPort51]

good points, just have to pull the drive gear off the shaft .

yep but a better way is to make an oil pump primer out of an old dist. this way all of the oil galleys that would normally be blocked by the dist. and allow oil to flow normally up to the top end, do their job. plus using a screw driver in a drill isn't very stable, you really don't want to let that oil pump shaft wobble around to much. oh and when you prime a motor you need to get a friend to turn it over by hand, a quarter turn at a time every so often, and keep on priming till you get good oil flowing out of all of the rockers.

 

[Cheepjeep85]

i also use a old mechanical oil pressure gauge on a short line hooked up, while i'm priming to make sure i've got good oil pressure. you can watch the oil pressure increase as you turn the motor over while your priming it.

 

[elizabeth968]

Me neither, I never heard of the need to bleed lifters but here is a link saying how to:
HOW TO: Bleed Your Lifters - evolutionm.net

Too dumb to be a joke. Someone does not know the difference between bleeding and draining. Draining the oil from a lifter serves no practicle purpose. Use of the paper clip serves only to relieve pressure for dissassembly of the lifter. Draining oil from a lifter accomplishes absolutely nothing unless you are cleaning the lifters. Who would do that much work for little to no useful purpose? Average cost of a lifter is barely over $2.

 

[Jeepman85]

Thanks for all the advise! I just put the rods and rockers back in and it all worked out without priming or bleeding the lifters! Don't know if I just got lucky or what, but it fired up on the first crank and had plenty of compression! Thanks again.