REPOST: 5k recirc flap repair procedure

[steveb@newkla.kla.com]

There have been a number of postings regarding fogging up the inside of the
windows.  Most responses have noted a leak in the heater core, but on these 
cars it is also possible that the fresh air/recirc flaps are not functioning 
properly.  I performed this procedure and posted my results to the list some-
time last year about this time, so I took some time to scan the archives to 
find the posting.  My hat is off to Dan S. (exposing my shiny head :) ... 
those hypertext archives are GREAT!  I was able to find the original posting 
from 23 Feb 1995.  Here it is, and I hope that it is of assistance to those 
of you in need ...

============================================================================

Did the fresh air/recirc flap fix last night on the '88 5kCSQ, so I wanted 
to give a quick report to the net about the experience.  I had received the 
Tech Bulletin by fax from Linda@Carlsen (Group 87 Number 90-01 Date 
11/30/90).  It states that it applies to '84-88 5000s & 100/200s from '89.

The procedure calls for removing the glove box and glove compartment liner.  
In addition, I found it useful to remove the plastic airbox cover over the 
A/C & blower in the engine compartment behind the firewall (which means 
removing the right windshield wiper).  

The problem with the car was that the plastic mount that held the vacuum 
motor in place had broken, as had the flap return spring.  The TB states 
that the mount breaks due to a shifting of the seal, causing the adhesive 
to seal the recirc flap shut.  I did find that the recirc flap seal had 
shifted (but the fresh air flap seal had not !?).  The replacement bracket 
is a pretty substantial piece of bent metal that gets screwed into the 
remaining plastic rails with two self-tapping screws.  If both flaps are 
removed the location can be accessed from above or below, but I found that 
it was more easily accessed from the passenger footwell.  The procedure 
states to attach the bracket with a certain self-tapping screw.  The screw 
that is called for has a "Phillips" head ... which is quite difficult to 
attach, even with a stubby screwdriver.  I would recommend getting two 
self-tapping sheet metal screws with the 1/4" hexagonal head and a flange 
to keep it from sliding into the socket.  If I used them I could have used 
a ratchet to attach the bracket.  I also pre-drilled small holes in the 
plastic (by twisting the drill bit between my fingers) to minimize the 
chance of breaking the plastic and making the screws easier to start.  

I did buy a replacement vacuum motor because I knew that there was a leak 
in the line, but I found that what had happened was that the line got pulled 
off the motor when the bracket broke.  The motor was in acceptable shape, 
but I replaced it anyway.  I'd recommend that the part not be purchased 
before the operation ... wait to see if you need one first.  

Since the spring had broken and there was no explicit diagram either in the 
procedure or the Bentley, I had to guess where it was supposed to attach.  
I connected it to a horizontal plastic bar that went between the same mount-
ing rails that hold the vacuum motor (there were no other candidates).  
Attaching the spring to the recirc flap was one of the more difficult parts 
of the process!  I recommend having a 6mm allen wrench handy to help with 
R/R of the vacuum motor and the spring.

Thanks to Carl DeSousa for working out the cost+20% at Carlsen!  This whole 
project cost ~$30 including the replacement vacuum motor!  It took me be-
tween 3-4 hours to perform.

Steve Buchholz
s_buchho@kla.com
San Jose, CA (USA)