Bendix Mag S4LN-21 P lead needed

[Gillie]

Older style shielded ”square nut “ P lead with external filter needed real bad .
If any of you fellas or ladies have a set in the used parts bin and want to trade for cash , please let me know .
Thanks
Bob

 

[Bob Turner]

I run those. I think you can still buy them - I machine the plungers from Teflon rod. Easy. Better to buy new capacitors.

 

[Gillie]

Thanks Bob . I am not having any luck sourcing the shielded lead .
will call Bogert Aviation today , they make unshielded p leads , I’ll ask about capacitors .

 

[Hiperbiper]

Aircraft Spruce has the filters. Might have the p lead too.
Chris

 

[Gillie]

Thanks for the help Hiper

 

[Bob Turner]

Shielded 20GA White Wire M27500-20TG1T14 | Aircraft Spruce ®

Shielded 20GA White Wire M27500-20TG1T14 This shielded & jacketed aircraft wire conforms to MIL-C-27500 & replaces MIL-C-7078/3. It incorporates MIL-W-22759/18 basic wire and features a Tefzel insulation, a shield of tin- plated cop

www.aircraftspruce.com

 

[Bartman]

For what it's worth, I had a great experience with SteinAir.com this week. They're an avionics/electrics shop with an online store and lots of helpful videos.

 

[Gillie]

Thanks Bob & Bart . Being a retard , I need all the help I can get

 

[Hiperbiper]

Gillie,
What is actually wrong with your p lead? Broken? Shorted?
Do you have all the parts?
Chris

 

[Gillie]

The shielding frayed and separated /broke at the nut that fastens the lead into the mag . The insulation on the lead wire where it passes thru the same nut is also cracked/broken and a strand(s) of the shielding poked thru the break in the insulation and shorted the lead out .
what I cant understand is how all the wear and tear occurred . Vibration maybe but that shielding is tuff stuff .

 

[Bartman]

if it is just the end of the wire that is worn, do you have enough slack to cut it clean and redo the terminals for the p-lead cable and the shielding?

 

[Gillie]

No Bartman , for safety sake , I need a good serviceable used/rebuilt or new lead-filter assy

 

[Bartman]

Gillie, I'm not that familiar with mags and the parts of them but we did replace the terminal on one p-lead during the annual last month. Can you post a photo of the stuff you're trying to replace? I'm curious what it is you're talking about.
Thanks

 

[Gillie]

 

[Gillie]

 

[Gillie]

These picts are from another fella that has the same P lead on his mag in his C180

 

[Bartman]

what is that part called?

 

[Gillie]

It is the P lead for a Bendix Magneto S4LN-21 . It is actually a airframe part . The “modern” equivalent is a MF3A

 

[Hiperbiper]

Magneto Filter - FAA / PMA Approved | Aircraft Spruce ®

Magneto Filter - FAA / PMA Approved Lone Star Aviation’s Magneto filter (FEED THRU) (Fail Safe Design) attenuates both low and high frequencies of noise generated from bendix magneto ignition systems. The firing of the aircraft spark plugs

www.aircraftspruce.com

A bit of soldering and you're good to go...

Chris

 

[Gillie]

Chris , I looked at that one but dont like the “pigtail” . On the older style , the P lead wire itself is more rigid with stiff insulation on it . It has to support the lead contact washer and 3/8” insulators and be pushed straight into the socket in the rear of the mag .
I think that the lonestar lead would work great for attaching a ring connector for mags with the external stud .
That said , if push comes to shove , I think that I could make it work .
Thanks for going out of your way to give me a hand .