Hydraulic lash adjuster question

[ejp2fast]

I just pulled off my head and rocker assembly. my haynes manual says that when you pull out the hydraulic lash adjusters they should not depress... on my number 3 cylinder on the intake side my hyd lash adjuster i can press it like a button in and out, and all of my others on intake and exhaust are solid. how do these exactly work and what makes them go bad? 91 Festiva GL, auto, FI..... thanks.

[Damkid]

they run off of oil pressure when the engine is running and "should" self adjust

[phantorn]

They should be hard to compress but its not a surefire way to check them

[ejp2fast]

i plan on replacing all 8 while i have it all apart..... is there another way to check beside how hard they compress?

[freshtiva]

All my shop manual says is:
" Inspect hydraulic lash adjuster operation by pushing down each rocker arm by hand. If a rocker arm moves down, replace the hydraulic lash adjuster."

[Dave G]

Opps! (I guess?) - when I had the yellow car's engine out I soaked the adjusters in solvent and got them losened up nicely so I could push the plunger in & out with my finger. They are not noisy, runs fine... I figured that zero clearance (which is what you have when they are frozen solid) is a bad thing.

[jglutz]

I think...I don't have any lit in front of me...but the manual says they should not push down while they are installed...meaning after taking the valve cover off only...try to push the rocker down at the valve. Not after the rocker and lash adjuster has been removed.

My recollection is the lash adj has an internal check valve assy that fills with (traps) oil and keeps it fully extended once it's filled with oil.

Jim D. would be best at this one.

[sasquatch]

is it true that you have to clean them out of oil each time you take them off?

[phantorn]

not to my knowledge

[phantorn]

The motor guy said to put them under oil and see if they pump up.They should after a couple of pumps and then be really hard.Noise while running is his major reason for replacing though and he replaces them all as yoy said you were gonna do

[phantorn]

under oil as in a can or bowl

[ejp2fast]

I don't know if i'll be replacing them now that i have called advanced auto parts, autozone and the dealer and they don't have anything......
does anyone have a FI parts car with the rocker assembly that would have the hyd lash adjusters?

[gottafesty]

rockauto.com sells the lash adjusters. I think they are like $12 or something.

[gottafesty]

check this post for a discount code to rockauto.

http://www.fordfestiva.com/forum/viewtopic.php?t=15984

[ejp2fast]

i actually checked rockauto.. where are they within the site? i went to ford-1991-festiva GL-engine... and nothing about hyd lash adjusters.. HELP