Lyman 4500 leaks

[tommag]

My 4500 extrudes a ribbon about 1/4" wide past the o-rings on the piston. I replaced the o-rings with the closest size I had on hand. They measured 1/8" wide, 1 1/8" O.D., and 7/8" I.D.

I heated the piston and cleaned the lube out of the grooves before installing new rings, but I still get that leak past the o-rings.

My thoughts:
Improper size o-rings,
Not enough heating time before applying pressure to the lube.
Just a Lyman thing, live with it.
Daniel has created a such a perfect lube in his Speed Green that it is impossible to contain:roll:

All help greatly appreciated.

Tom

[carpetman]

On Lymans and RCBS sizers when you finish using them, back off the pressure a few rounds. If left with pressure they will ooze.

[tommag]

Thanks, Carpetman.

[chaos]

I had an O-ring fail like you said. It is not a standard sized O-ring that is in any of my kits. I tried some that were close and they failed. I called RCBS and ordered one......which they sent for free......Replaced it and it never leaked again.

[madman]

If your "O" ring is under size in diameter you can remove the "O" ring and use a few wraps of dental floss in the grooves. Re install the "O" rings and test fit them. It should be a tight fit.

[monadnock#5]

With my 450 I've found I need to plug the heater in and walk away for at least 20 min. Without the preheat, I put too much pressure on the piston, so that when the sizer finally comes up to operating temp the lube squirts out in three different places.

Beyond that, +1 to those who spoke before me. When I'm done I back the piston off 2-1/2 revolutions, every time. That depressurizes the system, and I know that I need 2-1/2 revolutions to get me back to where I was on the next go round. A new O ring also sounds good. Lyman lubers are an art as much as a science. Any variable that you can easily eliminate is worth the relatively small price.

[dubber123]

Madman offered a good tip. I'll try to offer another; On the old 450's with the brass sleeve, (no O-rings), I removed the sleeve from the plunger, and wrapped enough Teflon pipe tape on the plunger body to make the brass ring a snug fit in the lube sizers bore. It's been a couple of years, and no leaks.