Lyman 450 pressure nut

[pilgrim98908]

I just got my old (purchased about 198?)Lyman 450 out of a box I put it in back in about 1991, the last time I did any casting. It was well and truly gunked up but I'm fixing that.

Taking it apart to clean brought a couple things to my attention, most of which I managed to resolve but this set of issues has me stumped.

See the pics below of my pressure nut. There are no O-rings on it, nor grooves for any, and I don't recall any ever being there - but it has been a long time. You'll see in the first pic that there is a very short stud (maybe .005 high) on the minor diameter of the piece, duplicated 180* around. Is this piece as it should be? Not having grooves, do the O-rings count on clean living and righteous thoughts to stay in place, or what?

Second photo, see the transverse groove across the upper surface of the nut. The multitude of scratches come from using a screwdriver blade to keep the nut from turning with the pressure screw as I tried, eventually successfully, to back it out. The groove is so shallow that I find it hard to believe that I put it to its intended use. So, what's it for? And if that is what it's for I'm gonna take a hacksaw and cut it deeper.

Finally, and this might have just been a lazy draftsman, but the Lyman exploded diagram shows the screw being threaded only a short ways top and bottom. Mine is fully threaded, which would appear to be necessary for it to function as I understand.

TIA,

Pilgrim

[avogunner]

That picture isn't of a 450 pressure nut. It looks like the seal plug from the bottom of the sizer but that should have an o-ring also. Since you're putting this sizer back into service after 20+ years, my suggestion would be to order a whole new pressure screw assembly (http://www.lymanproducts.com/store/page151.html). It's not expensive and will get you up and running in nothing flat.
Semper Fi.

[Ed_Shot]

+1 for the new pressure screw assembly. Bought my 450 about 1970 and only recently got the replacement kit....very pleased with it.

[pilgrim98908]

That picture isn't of a 450 pressure nut. It looks like the seal plug from the bottom of the sizer but that should have an o-ring also.
Semper Fi.

Well, yeah,but . . .

It's not a seal plug - it's properly threaded to act as a nut and it served in that capacity for more than a few years, even without O-rings. Apparently, with a tube of grease under, it there is enough resistance to rotation of the nut to allow it to work its way down the screw rather than rotate freely.

To be sure, I wound up with some lube (well, more than some, but not a lot) atop it when used, but it did function. Ignorance was bliss - it wasn't till I started overhauling the machine and reading stuff here that I realized something was amiss.

I don't recall if I bought the 450 new or from some reloader friend, so the provenance of the piece is uncertain.

It's good to see that there's a rebuild kit and silly to think that heavily-greased metal parts need be replaced, but there it is. I think before I order it I'll do some clearance measurement and try putting a couple O-rings on that weird piece; maybe even get a machinist friend to cut a groove. Can't hurt (I guess) and anyway, I never screwed anything up so bad I couldn't throw it away.

As to a seal plug . . . here's a pic of the base of my 450. I note the piece staked in; I read that the factory did that. My question is this: is that staked-in piece the seal plug or is that fine circular line part way to the center the rim of the seal plug? And if it is, can it be driven out from inside the grease reservoir with a brass or hardwood drift?

Pilgrim

[avogunner]

Hmmm, that's interesting. I've never seen one (pressure plug) that looked like that. Maybe someone's homemade version? It sounds like a fun project to reuse it....Good luck

[Hardcast416taylor]

This probably sounds like a stoopid suggestion, but. If you know anybody nearby that uses a 450 luber, ask to take a look at theirs - especially the bottom side.Robert

[pilgrim98908]

Hmmm, that's interesting. I've never seen one (pressure plug) that looked like that. Maybe someone's homemade version? It sounds like a fun project to reuse it....Good luck

More info, more questions

I just got nearly all of the old grease out of the reservoir and I see something in the bottom that makes ??? Over my head.

It is a very thin lip (looks like brass) nearly at the bottom of the resv. In fact, it looks like a sleeve with two small holes in it 180* apart. In further fact, what it looks like is a sleeve that would have fit around the minor diameter of the weird "nut," with the two little studs on the nut engaging the holes, as though the so-called "nut" were a two-piece assembly. A

The sleeve (I'll call it that for convenience of reference) apparently does not go clear to the bottom of the resv, though, for I can dig grease out of chambers below it that I take to be passages to the die.

I'm using heat to thin residual grease that's locking the sleeve in place and to expand the reservoir walls to create clearance around the sleeve, then using a hook to try to get hold of one of the little holes and lift it out. Hah! This might turn out to be a long, fiddly job but it must be done, for I'm pretty sure a whole new assembly won't go in there until the sleeve is removed.

[pilgrim98908]

Hmmm, that's interesting. I've never seen one (pressure plug) that looked like that. Maybe someone's homemade version? It sounds like a fun project to reuse it....Good luck

In light of my discovery of the "sleeve" I refer to in my previous post, I'm wondering the same thing. I can imagine some enterprising guy with a lathe machining the nut in my picture and getting fancy by making a sleeve for it to get a tight fit instead of those nasty old 0-rings that wear out. Then I buy it, run low on lube, it hangs up in the bottom and when I give the handle a hard pull the first time i had to recharge the reservoir the little tits pull out of their holes, leaving the sleeve well and truly stuck. X##%¥&$!!!

Pilgrim

[kayak1]

Well, yeah,but . . .

It's not a seal plug - it's properly threaded to act as a nut and it served in that capacity for more than a few years, even without O-rings. Apparently, with a tube of grease under, it there is enough resistance to rotation of the nut to allow it to work its way down the screw rather than rotate freely.

To be sure, I wound up with some lube (well, more than some, but not a lot) atop it when used, but it did function. Ignorance was bliss - it wasn't till I started overhauling the machine and reading stuff here that I realized something was amiss.

I don't recall if I bought the 450 new or from some reloader friend, so the provenance of the piece is uncertain.

It's good to see that there's a rebuild kit and silly to think that heavily-greased metal parts need be replaced, but there it is. I think before I order it I'll do some clearance measurement and try putting a couple O-rings on that weird piece; maybe even get a machinist friend to cut a groove. Can't hurt (I guess) and anyway, I never screwed anything up so bad I couldn't throw it away.

As to a seal plug . . . here's a pic of the base of my 450. I note the piece staked in; I read that the factory did that. My question is this: is that staked-in piece the seal plug or is that fine circular line part way to the center the rim of the seal plug? And if it is, can it be driven out from inside the grease reservoir with a brass or hardwood drift?

Pilgrim

The bottom of my 450 looks just like yours. My pressure plug doesn't look like your, mine has the 0 rings on it.

[JonB_in_Glencoe]

Your brass ring sleeved pressure nut was not homemade. It's the same one as came with all the lyman 45's.

As this has come up before, I am fairly sure that lyman sold their earliest 450's with this brass ring sleeved pressure nut.

Most people prefer the newer style with O-rings and Lyman sells them. But, I prefer the older brass ring sleeved pressure nut, if it hasn't been mangled, first you don't have to replace anything (yes the orings do wear), and if you do not use too much pressure, it's rare to have lube leak.

[pilgrim98908]

Well thank you, Jon. Your reply clarifies the thing for me and the picture looks pretty much like what I envisioned. Now the problem remains of how to get that sleeve out of the lube chamber. I guess I'll just keep heating the cast iron to expand it and trying to fish the sleeve out. Your pic helps a lot showing how I might get hold of it. Anybody else's thoughts will be welcome.

Pilgrim

[GP100man]

Knock the plug out the bottom , get the kit & install it .

Get the linkage update also .

When ya mount the sizer again be sure to put a gasket of sorts underneath .

[pilgrim98908]

Thanks for the advice, GP. I have updated linkage; in fact the press had it when I got it.

As to the kit - if I can knock the plug out through the sleeve it'll give me another avenue to remove the sleeve intact. And if that works I'll just try to rehab that piece. If I can't then a new unit is the answer.

Pilgrim

[JonB_in_Glencoe]

Knock the plug out the bottom , get the kit & install it .

Have you done this ? was it difficult? I have owned three different 450's with leaky bottoms and wondered if that was easy ? if the old plug is replaceable and just find a new oring to fit?
Jon

[avogunner]

Your brass ring sleeved pressure nut was not homemade. It's the same one as came with all the lyman 45's.

As this has come up before, I am fairly sure that lyman sold their earliest 450's with this brass ring sleeved pressure nut.

Ahhhh, that makes sense. So that's what a brass pressure screw looks like without the brass sleeve. Thanks Jon

[pilgrim98908]

Well, I got the sleeve out and it did finally require knocking out the bottom plug so that I could take a brass drift and tap the sleeve out from bottom to top. Just wasn't enough purchase anywhere on the sleeve to use a mechanic's pick to snag it and lift it out, not even with heat on the reservoir wall to expand the cylinder. Even driving it required persistent a tapping of one side and then the other all the way to the top.

For the info of those who might wonder, the bottom plug is staked in place but not so firmly that it resists being driven out with a brass rod and a light hammer. To do it, work way your with light taps around the circumference; two circuits did it for me.

I made a quick try at reassembling the nut and reinstalling it but the sleeve is simply too tight a fit, which may have been the source of the original failure. I could make the nut go down by putting the screw through it and tapping it down just an inch or two but I'm certain the fit was too tight to back it out with the screw in normal use. I had tap the other end of the screw to get it back out.

So, I'll reinstall the plug with a new O-ring, polish up my credit card, fire up the browser, and order the repair kit and a new depth adjusting screw; can't remember how I broke that one.

Pilgrim

For the mechanically curious ...

[pilgrim98908]

Jon, the plug was easy to tap out with a 1/4" brass rod I had handy. Give the plug the first tap, a firm one, on one side. Tap with increasing firmness until you feel it give little, then begin working your way around the circumference with more taps. It's not set in there very hard.

I'm going to make a base plate for mine out of 1/4" aluminum plate. That platewill be clamped to my bench between the 450 and the bench top by the mounting bolts. What I intend to do will require marking the plate in a fashion I leave to your imagination, but I'll have a machinist cut a circular 0-ring groove in the plate where the bottom plug will go. Then, with an 0-ring in that groove I'll bolt the machine down, thus sealing from external leakage any grease that gets past the bottom plug O-ring.

Pilgrim

[Larry Gibson]

Pressure nut on my 450 I got in '68 is the same brass one as yours. Subsequent three 450's have the 0 ring pressure nuts. Not sure when the change was made.

Larry Gibson

[JonB_in_Glencoe]

pilgrim and Larry,
thanks for the info.
Jon

[pilgrim98908]

The new parts came in. A thorough cleanup and fresh paint have given me this.

And that requires a good source for lube. Which is me, as it turns out, whipping up a load of Ben's Red Blend and figuring out a neat way (I hope) to load the thing. It is so obvious that I can't believe it hasn't been done here before but I don't find it in the search, so please bear with me if it has. I'm going to start a new thread in the Lube section for it.

Thanks to all who helped.

Oh! One more thing - the rebuild kit came with a fairly large, white, nylon bushing. I don't see any place for it, and the exploded diagram shows nothing like it. Can anyone tell me what it's for?

Kent

Well, never mind a thread featuring what I did. I looked in the right place and found PVC pipe molds have been made. No surprise at all.