Just chatted with the shop and they said that all the valves are not really bad, but, while they have the dashboard off we might as well replace all of them. The quote was $800.00 parts and labor. Does this sound reasonable?
'90 420 SEL (sold)
'72 280 SEL 4.5
'98 ML320 (for sale)
'05 Jeep Grand Cherokee Ltd (offroad in style)
'87 Chevy Blazer (AZ Pin Strips)