A bad diaphram will do several things -- it is resistant to flexing when installed, so the valve won't open and close on demand, tending to stay in one position or the other (that is, too much heat, not enough), it won't seal correctly when closed (too much heat, a real pain in the summer), and it will leak into the solenoid coil and corrode it, causing the valve to stick even more and eventually fail. This can cook some PBCUs.
Cheap and easy enough in a W126, no reason not to spend the $30 or so. Ditto for a thermostat -- if it won't come up to temp quickly under load in the winter, replace the thermostat. Cheap, fairly easy, make a huge difference. Note that a 603 in bitter cold weather will NOT come up to operating temperature at light load no matter how long you idle it. I've been stuck by a train and sat there watching the temp gauge slowly fall while I froze... Peter -----Original Message----- >From: "M.Afzaal.Khan" <[EMAIL PROTECTED]> >Sent: Oct 18, 2006 1:42 AM >To: Mercedes Discussion List <mercedes@okiebenz.com> >Subject: [MBZ] Heat & AC Failure monovalve > > >Ok Its better now we know the car model ! As mentioned >earlier on ,first replace the monovalve then check for other faults,which >simply may not exist after the monovalve has been replaced. > >i had a similar fault with varied a/c symptoms ,all was normal after >replacing only the monovalve. (worn diaphragm) >mak > 300SE/1990 > > >> That last posting regarding heat and AC failure - the car is a 1990 300SE >> thanks, >> les >> >> _______________________________________ >> http://www.okiebenz.com >> For new parts see official list sponsor: http://www.buymbparts.com/ >> For used parts email [EMAIL PROTECTED] >> >> To Unsubscribe or change delivery options go to: >> http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com >> >> >> >> -- >> No virus found in this incoming message. >> Checked by AVG Free Edition. >> Version: 7.1.408 / Virus Database: 268.13.4/476 - Release Date: 10/14/2006 >> >> > > >_______________________________________ >http://www.okiebenz.com >For new parts see official list sponsor: http://www.buymbparts.com/ >For used parts email [EMAIL PROTECTED] > >To Unsubscribe or change delivery options go to: >http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
