Took my 87 300D in today to have A/C charged. The car sat up last summer and the A/C wasn't used at all. Summer before required top off 1 lb of R12. A/C--climate control works good but obviously has a slpw leak therefore the top off---to my surprise the general automotive shop called and said the A/C would not accept a charge--they think expansion valve is blocking out the charge------is this correct? I didn't think the expansion valve did that--could anything else be preventing the charge?
TIA
Joel