Hydraulic Lifter Adjustement Problems Doing '80 Valve Stem Seals.....
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From: Massillon,Ohio USA
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St. Jude Donor '08-'09-'10-'11-'12
Hydraulic Lifter Adjustement Problems Doing '80 Valve Stem Seals.....
Valve seals going good, have cylinders 7,3 & 2 remaining to do Sunday afternoon. In putting the rockers back on and adjusting or trying to adjust them per the Service Manual, seems I can only adjust the rocker down far enough to take the lash out(to where you can just spin the pushrod with no play). The Service Manual also states to "tighten one additional turn"(which I already knew)to center the hydraulic lifter plunger, which I understand. What is happening when I try to do this as stated, having leftover air pressure in the cylinder, it's opening the valves enough where I can hear the remaining pressure escaping!!! Can this be right??? Also, on the valves that I have'nt done the seals yet I can definetly tell the rocker nut is down further on the stem at least a thread or slightly more than on the ones I've done. Seems something is odd, or is it best to just go ahead and tighten them down the additional "full turn"??? Is it because the engine is not running and oil pressure is not pumping "up" the lifter???
Melting Slicks
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From: Wichita, KS
Re: Hydraulic Lifter Adjustement Problems Doing '80 Valve Stem Seals..... (Paul Borowski)
STOP!
The lifters can bleed down and bottom out if you do this with the engine off. Just run them down until you get the lifters at zero lash and wait until you start the engine to adjust them.
The lifters can bleed down and bottom out if you do this with the engine off. Just run them down until you get the lifters at zero lash and wait until you start the engine to adjust them.
Race Director
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From: Beverly Hills/Pine Ridge Florida
Re: Hydraulic Lifter Adjustement Problems Doing '80 Valve Stem Seals..... (1979toy)
Hi Paul. Just got done helping a friend do this with his 67 hydraulic lifter motor so it's fresh in my mind. I don't have the service manual here, but I'm sure you do. Refer to the section on valve adjustment. It tells you to set #1 cylinder at TDC, and then set those valves listed, then rotate the balancer 360 degrees till #6 is at TDC and do the rest. I loosened the rocker nuts till I could push/pull the push rod up and down slightly. Then I tightened the nut till I couldn't push/pull anymore, then went down 1 full turn. I've never understood this "spin the pushrod" deal. Maybe I've got strong fingers, but I can spin that sucker with the rocker nut all the way down. :) Chuck
Racer
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From: Berlin,NJ,USA
Re: Hydraulic Lifter Adjustement Problems Doing '80 Valve Stem Seals..... (Chuck Gongloff)
I just did the adjustment on my 76 engine. Just take out the slack and go 1/4 turn down. After they are all adjusted start the engine and readjust by backing off until they start to click and then turn down 1/2 turn.
I know the book says 1 full turn but that is really tight.The engine will be happier at 1/2 turn.
To keep the oil from runnig all over I took and old valve cover and cut it in half, long ways. Bolt the two bolts on both sides and that will keep the oil from running all over.
I know the book says 1 full turn but that is really tight.The engine will be happier at 1/2 turn.
To keep the oil from runnig all over I took and old valve cover and cut it in half, long ways. Bolt the two bolts on both sides and that will keep the oil from running all over.
Pro
Joined: Feb 2002
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From: nyc ny
Re: Hydraulic Lifter Adjustement Problems Doing '80 Valve Stem Seals..... (Paul Borowski)
79toy is right bring the vavles to Zero lash. This will be enough to start the engine let it warm up then adjust vavles while running this is the only fulproof way. while the engine is running you can tell if a lifter is not at zero because they will make noise (claking sound) adjust down to silence not more. Then adjust to factory spec :smash: :seeya
Le Mans Master
Joined: Sep 2000
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From: Orlando Floriduh
Re: Hydraulic Lifter Adjustement Problems Doing '80 Valve Stem Seals..... (Paul Borowski)
Paul... The lifter's, having oil in them, actually DO open the valve after "0" lash but then bleed off. That's why the engine misses ( and you have to wait until it smooths out to go another 1/4 turn ) when you adjust the valves with it running. Here's a short cut. Measure (with accurate caliper's) the amount of threads above the rocker nut on one valve that is adjusted. Now just set the rest Almost to that piont and you will be very close. Then set them all with the engine running. :cool:
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Re: Hydraulic Lifter Adjustement Problems Doing '80 Valve Stem Seals..... (silvervetteman)
Thanks all for the comments. Looks like the best way is to do it while the engine is warmed up and yes I have seen the engine miss until it smooths out-reason for going a 1/4 turn at a time. It just seems the Service Manual acts like after all the lash has been removed, it's OK to tighten them the additional full turn without even starting the motor. I like the old "cut-in-half valve cover", seems that would work great. I was just hoping I'd be able to set the valves BEFORE starting the car because on an '80 I have the A.I.R. disconnected, EFE vacuum disconnected, the heater hose that goes over the passenger side valve cover disconnected, alternator and hose clip behind it pulled towards left inner fender with the belt off--it's just on these later cars it seems more difficult to "run" the car. It's surely not like the earlier simpler C3s!!!
