Lunkenheimer Primer

[Don]

I need to repair/ overhaul my lunkenheimer primer. Is there a repair/ overhaul manual for my 1946 BC 12D primer? I have searched the forum,but can't seem to find any info. Any help will be appreciated. Respectfully yours, Don

[Ragwing nut]

Re: Lunkenheimer Primer

Is it an early brass one? If so, only a leather packing in the nut, if it is bypassing internally, you will have to replace it

[Don]

Re: Lunkenheimer Primer

The primer is not brass. It is steel. The body appears to be a threaded tube with the intake and output lines on one end and the piston and packing nut on the other. Is it repairable? If so where do I look for replacement parts?

Don

[Ragwing nut]

Re: Lunkenheimer Primer

where is it leaking. The packing is the only thing replaceable and you will have to make that

[high time cub]

Re: Lunkenheimer Primer

http://www.supercub.org/phpbb2/viewtopic.php?t=15203&highlight=lunkenheimer

The original packing used under the nut is 3/32 braided cotton cord, 5 inches long.

HT

[Len Petterson]

Re: Lunkenheimer Primer

Cotton cord = candel veek?

[Don]

Re: Lunkenheimer Primer

Ragwing, HT, Len, Thanks so much for the replies and the info. It appears that the brass washer no longer stays in the nut, holding the packing . The washer has worn thin and slips down the shaft and binds the shaft so it won't move. Any suggestions?
Don

[Ragwing nut]

Re: Lunkenheimer Primer

Ragwing, HT, Len, Thanks so much for the replies and the info. It appears that the brass washer no longer stays in the nut, holding the packing . The washer has worn thin and slips down the shaft and binds the shaft so it won't move. Any suggestions?
Don

replace the primer

[Jim Doody]

Re: Lunkenheimer Primer

Does anyone have an idea what the pitch/thread is on the inlet/outlet of the Lunkenheimer primer? Or better yet a part number? It is not 5/16-32 as is pictured beside it. Notice that the threads are slightly tapered, I believe it is metric? Thanks, Jim

[Marv]

Re: Lunkenheimer Primer

I would say it is metric thread. The name sounds like German to me, and they definetely use metric threads and measurements. Marv

[clear_prop1961]

Re: Lunkenheimer Primer

Jim- I have a Lunkenheimer calalog from the late 1920's and it shows a 5/16-32 USF thread on the primer. This is the same thread for the 1/8" primer line and nuts you can get at a/c spruce.

Don- I don't know where you can get the brass ring/washer you mention.. you may have to make one. I'm looking at one on my desk and it is .528od and .062 thick with a inside chamfer on one end. The id is about .450. Hope this helps.
Jerry

[Len Petterson]

Re: Lunkenheimer Primer

Pipetread most likly 1/8 pipe tread it it is tapered.
Pipe is measured by the ID of the pipe in schedual 80 and therefore the pipetread is about 3/8" in diameter or as the book specs say:At the end of the pipe and tread .36351" at the inner end of thread 0.3840"
witha 27 threads per inch pitch.
There is also a 1/16 " pipetread very rare but I seen it in some smaller fittings and as pluggs in hydrualic valves. small OD is 0.27118 " and large innner end is is 0.29044".
Note what a pipe tread is always taperd and if you tighten it to hard it will expand the part it enters into and can/will crack it!
A good sealer is needed for the gasoline! NOT teflon tape!
My primer is using a Oring for piston seal but it is newer then the 46 still a " lunkenhimmer"
German by the name only! made in USA. if you need a leather packing make onesoke the leater in Neets Foot oil to soten it or cut up an old valet the leater vill take shape as you put in no large forces are needed if you du it rigth.
The brain is stronger then bran! in any case!
Len

[jmvolpp]

Re: Lunkenheimer Primer

The primer on N44305 is the brass, spring loaded, Imperial version, presumably original. Normally, it would require one pull to acquire fuel from the gascolator before it would fill, now requires several. Does this qualify as an internal leak (nothing visible outwardly) and, if so, could it be responsible for a less than smooth idle? Is this one rebuildable, or would I be aggravation ahead to replace it with a Kohler/Essex?

Mike V.

[Mark Julicher]

Re: Lunkenheimer Primer

It is possible that the primer is leaking internally. It uses leather gaskets and they can crack or dry out. Check valves are a ball and seat if memory serves me... and dirt could make them not seat. Disassemble carefully, clean, and put some EZ Turn on the leather and see if it helps. The old brass is brittle, so be gentle. This is NOT owner maintenance.

[jmvolpp]

Re: Lunkenheimer Primer

Upon inspection of N44305's Imperial primer, it was found that the small screen at the inlet port was nearly covered with debris. The balls and seats were in good shape, as was the piston and cylinder. All is well now after cleaning and reassembly. Thanks for the tip!

Mike V.