UKPaul

Hi,
I was trying to change my valve springs with the heads still on the engine. Filled the cylinder with air @ 130psi & compressed the spring. Trouble was that the keepers were stuck in the valve spring cap, so the spring just pulled up to the cap. If I used a different compresser which pushed down on the valve cap, then the valve opened. I there any way to free the keepers from the caps, because I really don't want to pull the heads off?
TIA
Paul

mapman

Try a light tap with a rubber mallet. :smash: Works for me.

norvalwilhelm

With air in the cylinder give the retainer a sharp crack with rubber or plastic hammer. It is common to have to rap a retainer with a rubber hammer. I have done heads both ways and find doing them on the car with air pressure is easy. Apply pressure with the valve spring compressor tool then give it a good hit with the rubber hammer and it will break loose.

Richard Cooper

Paul,
I just did my valve stem seals last weekend and I had the same trouble, just do like Mapman and Norval said. I used a brass hammer and tapped both sides of the spring, but I did it with no air pressure in the cylinder. You just want to give it a light tap, if you hit it to hard the spring could collapse to much and the keepers fall off letting the stem fall into the cylinder. I tried it with the air pressure in the cylinder and could not get the keepers to come lose so I tried it without air and it worked fine. Good luck.

Paul Borowski

When I did my valve seals two weeks ago on my '80, I used like a 7/8inch 1/2inch drive socket on an extension and gave it a quick, light rap while the cylinder is pressured up and you can tell right away by the sound it makes when the keepers are free and unstuck. :yesnod:

UKPaul

Hit it with a hammer? Excellent! Would that be a 16lb hammer, or something more subtle like a 12lb one? (then I can say to the GF, "Look, it's their fault, they told me to hit it. I didn't know it would break :( Erm.... can I borrow £1500 to buy those Trick Flow heads please?") :jester
Do the keepers free up quite easily with just a few taps? I did think of tapping the valve caps, but I've seen a spring compressor actually broken in 1/2 when some keepers refused to let go. I've also had a head leap up off of a bench when some keepers let go with a really loud "crack", after putting a LOT of torque on the compressor, so I was a bit worried that if the Vette keepers had seized in the same way then a lot of force would be needed (assuming that they've been in place for 20 years & 70 000 miles). Would it help at all if I soaked them in penetrating oil 1st? Or am I just being paranoid ;)
:cheers:

WESCH

Hi
Had similar problem when I replaced the valve stem umbrella seals on my 68 big block. The hammer trick didn't work on the solid lifter strong springs, so I had to turn the piston to TDC and push the valve against the piston.
This sounds horrible, but only light force is required to free the keepers. Once they are freed, the air pressure will keep the valve closed.
Be aware that if the piston is not at top dead center, the engine might turn with air pressure applied. On my car, this wasn't a problem due to manual gearbox holding it , but on a auto trans ?
Good luck. Gunther :seeya

xfactor974

Bring the piston up to TDC and don't even worry about putting a compressor to it. With the piston at TDC the valve doesn't have enough room to drop in.

Dalannex

Everytime I go to take a set of heads apart I always wack the caps on the springs with a rubber hammer to unstick them from the keepers before I even attempt to compress the spring. Works great. BUT, be a little careful to not hit straight sideways. A local machine shop had a new kid working there and he would really nail the side of the spring with a rather large ball peen hammer to get them freed up. They started to notice an unusual case of bent valves right around that time. Ends up he was hitting them straight sideways hard enough to bend the valves. Not that there's all that much danger of that though, he was really hitting them hard. :eek: He works behind the parts counter now. :lol: If you just give them a light smack with a rubber mallet, straight down on the spring on one side of the valve stem, they crack right loose. Later. :cheers:

-Justin


[Modified by Dalannex, 2:42 PM 4/9/2002]

UKPaul

Thanks for all the help everybody. I used a rubber hammer & a 13/16" socket (nothing special with the size, it was just clean!) to free the keepers. Worked a treat. Did it with the piston just down from TDC, so the valve head didn't hit it, & then brought it up to TDC to hold the valves up when I took the springs off.
But I've now got another problem :rolleyes: I noticed that the spring seats for the exhaust valves aren't as deep as the inlet ones. This is because the fitted inlet spring length is 1.19/32" (1.594"). The cam & springs that I've installed call for a fitted length of 1.7". Am I going to get spring bind? Think I need another post on this one.
Justin: That guy who's now behind the parts counter reminds me of somebody that worked in our production dept years ago. We were getting a very high failure rate which turned out to be the way this guy was fitting the new EPROMS containing my software. He was placing them over the socket & because he hadn't used a tool to straighten the legs up, they weren't aligned with the socket holes. His solution? Hit the EPROM repeatedly with a large hammer :smash: until it was at the correct height. The check to confirm correct installation was to turn the pcb over - if the EPROM didn't fall out then it was in OK! :lol: Unfortunately they sacked him :( I was looking forward to his next solution to a problem - it's not often you have an uncontollable gut laugh when developing software :D (I heard that he's changed his name to Bubba & has moved to the States ;) ).
:cheers:

norvalwilhelm

If you want to know about spring bind put the spring in a vice and compress it until it is solid. Measure this solid length. Be sure to use a retainer on the valve when doing this compression. Now take this compressed length of the spring only and subtract it from the installed height. Will it clear and do you have an extra .060 left over for safety.
If your installed height is 1.594 and the collapsed measurement of the spring is 1.100 add .060 to this value for safety so 1.594 minus 1.160 equals .434. If the lift of the cam is more then this you are in trouble. You can gain installed clearance by getting different retainers and also different keepers. Between the 2 you could gain and extra .100 installed height.