I am trying to bring the AC back to life in my 70 corvette.  I bought a new expansion valve and it is different from the one that is on the car now.  The one on the car does not seem to be the correct part.  It has a long bulb that is clamped to the AC line.  The correct expansion valve simply has the end of the copper sensor line turned into a tight coil. 

The question is does the "tight coil" attached at the same place as the bulb and how should it attached?  The bulb was attached with a clamp similar to a radiator clamp.

Thanks

Mickey

The bulb supplies expansion or contraction of an internal gas based on temperature.  By attaching the bulb to the line, or evaporator, it "senses" the temp, and responds.  The clamp is not uncommon for clamping to the line.  Just be sure to cover it with A/C insulting tape.  That's the black goo in strips.  This insulates the bulb to the line, and makes it more accurate and responsive.  If it's not insulated/covered, the surrounding air will affect it's operation, and cause malfuncting A/C, when nothing else is wrong.

The expanded or contracted gasses apply varing pressure on the expansion valve.  This causes the valve to open or close, and change freon flow.   The coils in the line are not going to affect the operation of the unit as a whole.  It just makes for a neat install.  Replacements may not be coiled to allow different mounting locations.   If everything else fits, there is no reason you cannot gently coil the line.  Just take great care not to kink it.  That will ruin it's operation.

Ken,

Thanks for the reply.  With this new part (which should be the correct part), there is no bulb.  Instead of the copper line ending with a bulb it ends with this very tight coil.  Imagine if you wrapped the end of the copper line as tightly as you can around a ten penny nail.  If you go to Eckler's and look up and expansion valve for a 1970 you will see what I mean.

Should I clamp it the same way as the other and put the insulation tape around it?  Do you think it will make sufficient contact to read the temp properly?

Thanks

Mickey

Just a bit different design.  Yes clamp it as before, and insulate it.  Be sure not to collaspe the coil of tube as you tighten it down.  This could cause it to rupture and fail before putting it to use.  You just want it snug against the tube to transfer the temperature.  I would think the correct end could be found, but there should not be a problem with the one you have.