found black tar like substance surrounding my expansion valve
 

what is the black tar like substance i found caked almost completely over my expansion valve when i removed it. Is it suppose to be there. what is it's purpose. Thanks for any help you can offer. Ray, in the 95 degree heat and humidity in South La.

Does the car have an aftermarket "rust or noise proofing" material applied to it?

Also, it it the original expansion valve? It could also be lots of oil residue and road grime mixed together over the years.

Its insulation and a moisture barrier. The TXV gets cold and without the black stuff applied, will form condensation which then will drip in undesireable places.

ray m,

Usually it's A/C insulating tape, called Prestite. Forms an amorphous black mass/mess with time ;)

black tar cover
 

Should i get some from NAPA or someone and apply it to the new one. or can i insulate the thing with that styrofoam in a spray can they sell at Lowes or something

Expansion Valve
 

1984 300d Turbo 139k
Use Styroform Or Pipe Insulation With Tie Wrap I Use Two Cleaning Pads, Just To Keep Water Out New Frezze Up Valve They Disable The Compressor If The Evap Gets Too Cold

That gooey stuff is also called monkey doo. Helps to insulate where foam is just too tight to work correctly and will help keep the line from sweating.

monkey doo
 

I can identify with that discription. Thanks Diesel Giant. The new evaporator is comming from you and I will wrap it. It wasn't in the directions you gave for ac system change over. Thanks all RAY M