<VV> Thermostats

[J R Read]

Well, I've had one or two over the years which seemed to gradually fail.  By that, I mean that the bellows were not tightly closed (like new), but they were not fully open either - let's say, they were 15% expanded.  In those cases, the door was not tightly closed (when cold), but certainly not fully open.  Maybe open 1/8 - 1/4 inch.  IIRC those stats failed within 6 months of my first noticing that slightly open condition.

As you describe your stat problem, I think that I would check again for a possible drag on the movement of the door.

Later, JR

  ----- Original Message ----- 
  From: Jim Simpson 
  To: J R Read 
  Cc: Virtual Vairs 
  Sent: Tuesday, July 31, 2012 11:00 PM
  Subject: Re: <VV> Thermostats


  Every thermostat that has failed in my car has failed "open" (fully expanded).  The bellows is designed to be at full expansion when it springs a leak and the butyl alcohol evaporates.  That's what bugs me about this one; if it is opening at all, it seems to opening at a higher than normal temperature.  That's certainly NOT a normal failure mode.

  But I may be over reacting and perhaps the damper door is just closing before I get back to check on it.  That's why I wanted to see what the "normal" opening temperature is.

  I've heard that the reproduction thermostats fail more often/more quickly than the GM originals, but I like to see some data on that.  I've certainly had a number of GM originals fail over the last 44 years.  (And I think I'm handling them correctly -- for instance, not putting any torque on them.)

  So does anyone have a surplus of original GM thermostats that they want to sell?

  Jim Simpson
  Group Corvair


  On Tue, Jul 31, 2012 at 11:03 PM, J R Read <hmlinc at sbcglobal.net> wrote:

    The "fail"position is open.
    Later, JR