My faithful LM13, been working for years, suddenly stopped.

Found green oil inside case, oil leaking out the case at front, and no
HV at plates and filaments not lighting were the first problems.
Found 2 bad oil filled bathtub caps, one leaked oil, and fixed both
which restored plate HV to the 67 plate. HV at 77 and 6A7 is unknown now.

A serious problem is filaments of 6A7 and 77 tubes will not turn on
unless I do strange things to position those tubes in sockets and then
carefully tighten their chassis clamps. HAve to jam styrafoam between
6A7 and metal frame to make filaments light no matter how I tighten tube
base clamps.

I see that all 3 tubes pins are barely touching the socket contacts
during insertion. Do not know why pins do not push deeply into socket
contacts.

Since LM13 worked for years, apparently this shallow barely touching pin
to socket WAS OK originally and STILL must be ok and normal. Nothing
has changed about this tube set. The filaments all measure 5 ohms.
Possibly there is corrosion on the socket contact where tube pin
touches. CAIG contact cleaner DEOXIT does not help corrosion.

Using two screwdriver blades to supplement the filament pin to socket
contact connections, I can make the filaments of both 6A7 and 77 light
up. Their filaments are in series.

Really need help, suggestions, hints with this filamanr problem.
The problem is NOT INTERMITTENT...rock solid.

Thanks, 73, W6MIK, Dave