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Bleeding lifters

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jakelandry

10+ Year Contributor
976
157
Oct 13, 2009
Minden, Louisiana
I’ve bled down my lifters for years using various solvents, oils, ultrasonic cleaner, etc. Went to install a set of new gsc lifters today and noticed that their install sheet said something quite the opposite of the standard procedure I’ve used for 10+ years now.


It really seems like you’re doing the opposite of bleeding the lifters if you’re replacing the air with oil. I fail to see the purpose of releasing the plunger and purging the oil just to replace it with more oil which will retain the lifter at max height on startup conditions. Anyone care to comment?
 
Honestly that makes zero sense. We are bleeding the lifters because they can not be fully pumped up as it could cause a valve to hit a piston if the lifter is not operating in its correct range because of over pumping/full.

I only swear by 1g small hole lifters in all my personal cars, nothing fits in those things so it's a 45 min job on the bench vice at a slow squeeze bleed. On 3g revised lifters I also use a small allen wrench as listed above to push out any un wanted oil.

Star the car and let warm up and after about 10-15 min of normal slow driving and they should refill properly as the lifter tick dissapears.

Moral of the story, you and everybody else has been doing correctly for the past 30 years, don't worry bout it.
 
I bleed then cycle clean oil and re-bleed if I can, but my lifters go in lubed but NOT pumped up, always bled. Safe to not bend cute little valve stems/heads :)
 
I follow the procedure in the 3000GT FSM and use diesel fuel to prime and bleed them. They can be full and once installed they will not pump up on starting but still lube them until the oil fills them.

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I follow the procedure in the 3000GT FSM and use diesel fuel to prime and bleed them. They can be full and once installed they will not pump up on starting but still lube them until the oil fills them
this is what my dad used to do
 
On my GSC lifters i did the oil and bled after so they were squishy. They need to pump themselfs up inside bit dont forget the spring inside the GSC is also stiffer then oems so its essentually already pumps up when bled anyway and can support itself better vs oem can
 
What if everyone has bled lifters down for the past 30 years for no reason (other than to purge contaminants)? Just going to present a scenario here, nobody hang me for it.

Argument 1: The FSM says to do it. I don't have a fsm in front of me now, but does it say why? I mean it also has a guide on how to replace a head gasket but you don't just do it for fun. Maybe it is suggesting that you follow that procedure when cleaning old lifters? The procedure also leaves you with a lifter filled with incompressible fluid which would "hang the valve open and risk contact". Maybe it's physically impossible to have piston contact on a stock cam grind with stock valve install height and max lifter travel. I don't know.

Argument 2:
People say they leave them bled down to prevent the valves from hanging open and contacting a piston, but are we really foolish enough to assume that GSC doesn't know this? They make a cam with ~1/2" of lift and 280 duration, they make lifters, valves, and valve guides but they don't know anything about piston to valve clearance? Maybe you say " it doesn't hurt anything to install them bled down". This is the logic i've used for 10+ years but I've also had ticking lifters in every single motor I've ever run (new old, 1g, 2g, 3g, cleaned, various oil types and pressures, etc.) after this procedure. By this same logic, you could also potentially toss a rocker with bled down lifters and a valve height below spec in an extreme case or with an improperly shimmed regrind cam. Maybe it's physically impossible to have piston contact on a "huge" cam grind with stock valve install height and max lifter travel. I don't know.

With age I find the more I question myself on topics I know, the more I learn I've blindly done things for many years. I know there are 100 threads on this. I know nearly every person on this forum has bled down lifters and assumes they know how to do it correctly. I know lifter tick was a huge concern back in the 90's when everyone with a new dsm had 20k on a motor and it was clanking like it had an issue. What I don't know is the purpose and proper way to "bleed" lifters.
 
For what it’s worth you say your lifters tick in any motor/ any lifters/ any various combination. I have gsc 3g revised lifters in my 2g with the kiggly hla regulator and I haven’t heard a peep from mine.

On the stock motor they were quick noisy upon warm-up until the above upgrades. I followed the gsc install recommendations with BC 272s. No issues here.

-Daniel
 
What if everyone has bled lifters down for the past 30 years for no reason (other than to purge contaminants)? Just going to present a scenario here, nobody hang me for it.

Argument 1: The FSM says to do it. I don't have a fsm in front of me now, but does it say why? I mean it also has a guide on how to replace a head gasket but you don't just do it for fun. Maybe it is suggesting that you follow that procedure when cleaning old lifters? The procedure also leaves you with a lifter filled with incompressible fluid which would "hang the valve open and risk contact". Maybe it's physically impossible to have piston contact on a stock cam grind with stock valve install height and max lifter travel. I don't know.

Argument 2:
People say they leave them bled down to prevent the valves from hanging open and contacting a piston, but are we really foolish enough to assume that GSC doesn't know this? They make a cam with ~1/2" of lift and 280 duration, they make lifters, valves, and valve guides but they don't know anything about piston to valve clearance? Maybe you say " it doesn't hurt anything to install them bled down". This is the logic i've used for 10+ years but I've also had ticking lifters in every single motor I've ever run (new old, 1g, 2g, 3g, cleaned, various oil types and pressures, etc.) after this procedure. By this same logic, you could also potentially toss a rocker with bled down lifters and a valve height below spec in an extreme case or with an improperly shimmed regrind cam. Maybe it's physically impossible to have piston contact on a "huge" cam grind with stock valve install height and max lifter travel. I don't know.

With age I find the more I question myself on topics I know, the more I learn I've blindly done things for many years. I know there are 100 threads on this. I know nearly every person on this forum has bled down lifters and assumes they know how to do it correctly. I know lifter tick was a huge concern back in the 90's when everyone with a new dsm had 20k on a motor and it was clanking like it had an issue. What I don't know is the purpose and proper way to "bleed" lifters.
yes i also question many things in life i once thought i knew LOL

the idea is you want them to bleed up themselfs again, same as how i read here many years ago while doing the work ( might of been in haynes also but not sure as it was many moons ago now ) i think it was said you rev it to 3k ish to re pump them up and then they shut up again.

it worked then and will work now so its 2 ways, bleed and allow to bleed up or bleed and repump leaving them hard for install.

a post from 2006 says dsm says leave them down and a 3kgto forum says use diesel fuel and leave them pumped up! so its both ways will work and what goes better for you perhaps?
i just rebled mine and left them in a pot and when i go to install them i will bleed them in the oil and leave them down as i did before so they can build them selfs up. it worked the first time but i dont see any technical reason to leave them pumped up? yes oil pressure keeps them pumped up anyway but they self adjusting where as leaving it full is not self adjusting till it thins out some so thats what im rolling with LOL for now till i learn a new reason at least haha
 
a 3kgto forum says use diesel fuel and leave them pumped up!
If you use diesel fuel they don't stay "pumped up", it doesn't take much pressure to cause them to leak down/collapse unlike motor oil. What it does do is lubricate them and eliminate any air in them. Once the oil starts reaching them it replaces the diesel fuel and they act normal.

I haven't measured anything but the point of the lash adjusters is to keep the roller on the rocker in contact with the cam lobe and there is some anecdotal evidence that fully extended they can keep the valve from closing.
 
BogusSVO always leaves his spare good lifters just soaking in a (giant) can of diesel fuel, and so I've always done that too. I've just bled them out before installation and never had an issue. I have however personally witnessed a 4G63 bend 10 out of 16 valves on start up when the lifters were left pumped up. Dude said eff bleeding or soaking the lifters and just started it. As Steve said, this is super anecdotal evidence but man did that stick with me.
 
What if everyone has bled lifters down for the past 30 years for no reason (other than to purge contaminants)? Just going to present a scenario here, nobody hang me for it.

Argument 1: The FSM says to do it. I don't have a fsm in front of me now, but does it say why? I mean it also has a guide on how to replace a head gasket but you don't just do it for fun. Maybe it is suggesting that you follow that procedure when cleaning old lifters? The procedure also leaves you with a lifter filled with incompressible fluid which would "hang the valve open and risk contact". Maybe it's physically impossible to have piston contact on a stock cam grind with stock valve install height and max lifter travel. I don't know.

Argument 2:
People say they leave them bled down to prevent the valves from hanging open and contacting a piston, but are we really foolish enough to assume that GSC doesn't know this? They make a cam with ~1/2" of lift and 280 duration, they make lifters, valves, and valve guides but they don't know anything about piston to valve clearance? Maybe you say " it doesn't hurt anything to install them bled down". This is the logic i've used for 10+ years but I've also had ticking lifters in every single motor I've ever run (new old, 1g, 2g, 3g, cleaned, various oil types and pressures, etc.) after this procedure. By this same logic, you could also potentially toss a rocker with bled down lifters and a valve height below spec in an extreme case or with an improperly shimmed regrind cam. Maybe it's physically impossible to have piston contact on a "huge" cam grind with stock valve install height and max lifter travel. I don't know.

With age I find the more I question myself on topics I know, the more I learn I've blindly done things for many years. I know there are 100 threads on this. I know nearly every person on this forum has bled down lifters and assumes they know how to do it correctly. I know lifter tick was a huge concern back in the 90's when everyone with a new dsm had 20k on a motor and it was clanking like it had an issue. What I don't know is the purpose and proper way to "bleed" lifters.
While you are using cams for hydraulic lash adjusters, the ramp is designed for zero lash. So if bled down, valve/valve seat may be damaged by seating valves too fast. If pump up, the risk of valves not closing properly and it may burn valves would be concerned more than the risk of piston/valve contact. It's the same theory why not recommended to use solid lifters with hydraulic cams.

Like Steve mentioned above that using diesel is the original way that Mitsubishi shows in the factory service manuals (Diesel number 2 in Japan. I don't know if Japanese #2 is the same as the US #2). And there is a tool (leak down tester for HLA) for the lifters to determine if it's time to replace or not. I sometimes see the FSM in english mistranslated or skipped some info.

1st pic for inspection.
2nd pic for installation.
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Thank you everyone for your input. @steve ive always been under the impression that the diesel was just a cheap solvent to purge old oil and trash out. Though it does make some sense that it would give a little more than oil due to its viscosity and ability to creep out the lifter’s clearances, it’s still an incompressible fluid so i feel like that’s a risk of falling under the “hangs your valves open” category. That said, I do think that’s a valid argument and probably the most sensible explanation I’ve heard in favor of installing them pumped up.

I suppose using that same argument, who’s to say that they don’t bleed down to the right height just from cam pressure when installed with oil? Sure they take the cam’s full ramp without collapsing, but that is an instantaneous force with some oil pressure added behind the oil’s incompressibility. Perhaps 20 seconds of constant force if overextended is enough to push a slight amount of oil around the check ball’s seat and set the lifters at a point of contact rather than fighting to keep the valve open.

BogusSVO always leaves his spare good lifters just soaking in a (giant) can of diesel fuel, and so I've always done that too. I've just bled them out before installation and never had an issue. I have however personally witnessed a 4G63 bend 10 out of 16 valves on start up when the lifters were left pumped up. Dude said eff bleeding or soaking the lifters and just started it. As Steve said, this is super anecdotal evidence but man did that stick with me.

I also keep my old lifters submerged until I’m ready to use them, but that doesn’t explain why gsc suggests pumping new lifters full of oil to an incompressible state.

Every scenario I’ve ever seen where someone has bent valves (online only, never in person) has been by people who also admitted they never checked their valve height, or ran regrind cams with washers for shims, or never checked valve clearance to begin with. Not to challenge your statements or anything just stating my research/experience also.
 
After contacting gsc, I figured I would offer their response for future searches.

“If your protrusion height of your valves is correct and the base circle of your cams is correct then our lifters will not hold your valve open at full extension. You also do not have to put them in at full extension simply push the lifter down slightly like you do to bleed and release the check ball mid stroke. The lifter will not have air in the bottom and it wont be a full extension.”

My interpretation:

1. Proper geometry won’t hang a valve open at max lifter height.
2. If you still don’t trust them…After purging all air and locking the lifter at max height, depress the check ball, push lifter downward 1/2 travel, release check ball, allow spring to return lifter to max height allowing partial travel but limiting air trapped inside.
 
I always pump them up. I've never seen a 4g63 with scorched cam lobes,. You want to get the air out of them to fill them with oil, bleed them of air which will prime them with oil

So you install the camshaft and it presses down on the rocker and releases the built in oil pressure so that rocker is now set, and the higher risen lifter is full of oil like it would be if it was in the proper lift position for the valve, full height and filled with oil.


If youre not pre pumping them youre waiting for the oil pump to send pressure into the head to fill the lifter. Why wouldnt you already have them filled with oil like they would be when you removed them from the head

Pressurize them so the lifter doesnt wait for the pressure from the pump to the head
 
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