Leaking primer in my L-2M

[SteveR]

I have a leaking primer in my L-2M. I haven't disassembled it yet, but I assume there are some O-rings or gaskets that will need to be replaced. Does anyone know what O-ring sizes are needed? I'd like to have them on hand when I take it apart.

Thanks!

[3Dreaming]

Re: Leaking primer in my L-2M

What kind of primer?

[3Dreaming]

Re: Leaking primer in my L-2M

If you let me know what you have I might have some Orings I could send you. I have a big bag of primer Orings.

[SteveR]

Re: Leaking primer in my L-2M

Thanks, I appreciate the offer! I will get a picture of it and post here.

[SteveR]

Re: Leaking primer in my L-2M

Sorry for the delay, I finally took a picture. It is a Lunkenheimer primer. Apparently some of these are sealed with a packing thread instead of an O-ring. People on the supercub forum have re-packed them with teflon coated plumbing string, but I don't like the idea of having teflon in the fuel system. Maybe I'll take the string out and just coat it with a light layer of fuel lube?

If anyone has experience with the Lunkenheimer I'd like to hear it. Looks like these have been around for about 100 years.

[Ragwing nut]

Re: Leaking primer in my L-2M

Sorry for the delay, I finally took a picture. It is a Lunkenheimer primer. Apparently some of these are sealed with a packing thread instead of an O-ring. People on the supercub forum have re-packed them with teflon coated plumbing string, but I don't like the idea of having teflon in the fuel system. Maybe I'll take the string out and just coat it with a light layer of fuel lube?

If anyone has experience with the Lunkenheimer I'd like to hear it. Looks like these have been around for about 100 years.

some of those had a leather packing. I have one of those apart and that is what it looks like. I have a couple new ones too, but won't guarantee they won't leak without being checked first.

[Hank Jarrett]

Re: Leaking primer in my L-2M

This is the primer used in the BC-12 Taylorcraft. Part of the group is currently trying to get the right leather Cup Seals and I found 4 of them. One of the guys is going to rebuild and test one before we try to get more (in case there is a size problem and we have to make them larger). If the interior looks like ours measure the bore of the primer and we will see how close to ours are.
Note that the cup seals ARE NOT like the patent drawing shows. Evidently the original seal configuration wasn't as good as it could be. ;-)

Hank

[LostnSpace]

Re: Leaking primer in my L-2M

Sorry for the delay, I finally took a picture. It is a Lunkenheimer primer. Apparently some of these are sealed with a packing thread instead of an O-ring. People on the supercub forum have re-packed them with teflon coated plumbing string, but I don't like the idea of having teflon in the fuel system. Maybe I'll take the string out and just coat it with a light layer of fuel lube?

If anyone has experience with the Lunkenheimer I'd like to hear it. Looks like these have been around for about 100 years.

I maintain a 1929 New Standard and the primer in it is exactly what's on the printed page, gary

[Hank Jarrett]

Re: Leaking primer in my L-2M

When you open it up to rebuild it please take photos and post so the rest of us will have an idea what we will face.

[high time cub]

Re: Leaking primer in my L-2M

Sorry for the delay, I finally took a picture. It is a Lunkenheimer primer. Apparently some of these are sealed with a packing thread instead of an O-ring. People on the supercub forum have re-packed them with teflon coated plumbing string, but I don't like the idea of having teflon in the fuel system. Maybe I'll take the string out and just coat it with a light layer of fuel lube?

If anyone has experience with the Lunkenheimer I'd like to hear it. Looks like these have been around for about 100 years.

Hi SteveR,

Whether you use the old string packing or replace it with a new one, you can simply apply a mixture of graphite powder and fuel-lube. Cotton candle wick works well as new packing material.

If you completely disassemble the plunger, be sure the concave side of the brass washer is facing the packing.

Along with the general care and feeding of these old Lunks, you occasionally have to tighten the packing nut if it starts to weep. Leave some threads between the fascia nut and the packing nut for this purpose.

I’ve repacked these primers successfully with cotton string as well as teflon coated string - both work OK. One catalog I have describes the kit for the Parker large barrel primer as having a neoprene seal and teflon cord for the packing nut. A little teflon coated string in this application shouldn’t be a problem.

Do you have the short or long-drink model Lunk?

The yellow 1930 catalog page you posted is actually from my collection. The small globe shut-off valve shown on that page can be added to any Lunk. Wow, 100 year old Lunkenheimers - imagine that….

Best,

HT & V