Lyman 45 pressure nut

[Chuck Perry]

This past weekend I picked up a Lyman 45. I am just in the learning stages of casting, so bear with me. The press was heavily fouled with about 100 years worth of old lube. I boiled the press for a couple hours and now have it pretty darn clean, right down to the bare metal in a few spots unfortunately! A kind soul over on THR posted a .pdf of the original manual, and I have been going over it trying to figure this thing out. It seems I am missing the pressure nut. I have the reservoir cover and the threaded pressure rod, but there is nothing else inside the cylinder. Am I correct that there is no piston or other assembly that goes inside the reservoir cylinder except the pressure nut? I was digging around on this site and saw a few references to people buying replacement Lyman 450 pressure nuts and using them on their 45's. Are there any other parts I need to purchase? Should I buy the o-rings also?
Thanks in advance. I just joined the site tonight and can see that I will be losing many hours here!:drinks:

[454PB]

You are correct, the pressure nut is all that is contained under the reservoir cover. My older 450's have a pressure nut that utilizes a brass compression ring that finally quit working, so I order some of the newer type pressure nuts (which use two O-rings) and replaced them. They work much better!

[imashooter2]

You get the nut and O rings complete when you order from Lyman. I've got three 45's. I run one with the old brass skirt and plastic bag gasket and the other 2 with the new style O ring nuts.

[Chuck Perry]

Thanks guys, I'll order the part today. I did find my pressure nut; it was bottomed out in the reservoir and wouldn't budge. Another question: the manual talks about compressing a brass ring and putting it in the reservoir over top of the pressure nut. There is a brass key chain ring looking thing that came seperate from the machine with mine. I don't see anyway to compress this thing enough to make it fit in there. Is this what the plastic bag fix I read about replaces? So, when I get up and running, I'll fill the reservoir with lube, load the pressure nut, top it off with a plastic bag and then cover it all with the top cap? There seems to be nothing that holds this top cap in place, is that correct?

[imashooter2]

The plastic bag goes under the brass skirt and seals the split where most of the leakage occurs. Place a standard sandwich bag over the nut, rough trim off at the top of the nut and insert the unit such that the screw goes through the bag. The plastic covers the entire interior of the nut and is trapped between the nut and the side of the reservoir tube.

The new O ring nuts don't need anything added to seal efficiently.

Nothing goes on top of the pressure nuts. Fill the reservoir with lube, screw on the nut, cover with the cap.

You did get the old nut out right?

[Dennis Eugene]

or you could just buy a Star. Dennis

[imashooter2]

Question: How do I fix my Chevy?

Answer: You should buy a Ferrari.

[floodgate]

Chuck:

I was about to suggest that you check to see if the old pressure nut had bottomed out in the reservoir - I see that it has. It should have a couple of dimples in the top; or you can see the split in the brass piston ring if it is the older type. Either way, try to hold it from turning with a punch or a long, skinny screwdriver while you turn the screw to jack it up and out.

Floodgate

[Chuck Perry]

Thanks again guys. I did get the nut out; old style brass skirt. Parts are on the way, going to start looking around for sizing dies. This project is getting expensive; with the Lyman order today I'll now have $20 invested in my Lyman 45. Guess I shoulda just got the Star:mrgreen:

[Dennis Eugene]

lol good one

[pincherpartner]

Hi Chuck,
I hope I'm not too late with this post, but do yourself a favor and order a new pressure screw. I recently "inherited" the no. 45 and found that the old screw's base came off the screw. (Yes, I'm still a Nooby to casting) The new ones are a one piece design and should eliminate this problem. Then the only problem is that the old reservoir cover will not fit. So you can either drill it out, order a new cover (which I'm assuming would fit over the reservoir tube), or just leave it off which is what I am doing. Now with the new screw it works perfectly. Or as perfectly as it can without it being a Star.
:mrgreen:

[Chuck Perry]

pincherpartner,

Thanks, but I simply can't afford to spend anymore on this money pit :mrgreen:

My pressure screw looks ok so far(it'll break the first day right!?!), but it's good to know that it too can be replaced with modern parts.

[pincherpartner]

Well if you do, let me know as I bought a spare thinking that it would be made the same way as the original. But the new design should last.

[Chuck Perry]

Got my new pressure nut yesterday; fits great! I ordered 3 o-rings and received 2 installed on the nut, plus one spare. Kinda thought that the pressure nut would have included these, but oh well, can't complain for what I paid. Got another question now. Is there anything that goes into the base where the die rests? Any kind of o-ring or other seal that I need to check on? Was reading another thread about a similar item on the 450, got me worried. With no die installed, I can see daylight looking down thru top to bottom.

[kodiak1]

Chuck Perry you should look at Carbine Tree and see his pressure nut assembly and they work on the 45's excellent tighten her down and you can do 50 plus bullets before tightening it again. The one I put on the 4500 works great but my handle gets in the way a bit.

Ken.

[floodgate]

Chuck Perry:

"Is there anything that goes into the base where the die rests?"

No, when properly seated, the taper on the base of the die body seals on a matching taper in the base of the tool. I've never noted any leakage at that point in normal use.

Fg

[imashooter2]

Got my new pressure nut yesterday; fits great! I ordered 3 o-rings and received 2 installed on the nut, plus one spare. Kinda thought that the pressure nut would have included these, but oh well, can't complain for what I paid. Got another question now. Is there anything that goes into the base where the die rests? Any kind of o-ring or other seal that I need to check on? Was reading another thread about a similar item on the 450, got me worried. With no die installed, I can see daylight looking down thru top to bottom.


Very odd... I ordered 2 nuts and they both came with O rings installed. I didn't order any O rings since I expected them to be on the nuts.

The die will come with an O ring at the top. No further seals required. It'll be fine. Sometimes if you're cranking on the pressure, they can leak a bit around the screw in the bottom of the reservoir. Mounting it on a thin cardboard gasket fixes that.