Date: Fri, 17 Dec 2010 12:06:04 -0500
Reply-To: David Beierl <dbeierl@ATTGLOBAL.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@ATTGLOBAL.NET>
Subject: Bosch heater blower disassembly/reassembly
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This will have photos later, but for now here's how to do it:
Removal - Have everything at room temp or warmer. Remove two wire
spring clips retaining motor in case. *If there aren't any, stop
right there, because it isn't a Bosch and you're on your own for now.*
Note the clearance between housing lip and impeller and then split
the housing -- gently twisting a 3/8" screwdriver tip in the openings
will release the catches one by one. Don't lose the rubber piece
that you must remove. Note depth of shaft in impeller and angular
alignment of motor in case. Take care not to knock off any metal
clips on impeller -- they're for balance.
Set 4-6" vise jaws just wider than motor and align case so that lips
of motor housing have maximum support from jaws. Make certain they
don't foul the motor. If necessary you can improvise something but
it needs to have some weight behind it. A foot of 3" pvc pipe
stuffed half full of rags and sitting on concrete comes to mind.
Take a drift (1/4" IIRC) and *large* hammer - lead is great and a
three-pounder is not too big - and drive the motor out in two
stages. First stage is to fairly gently make sure the motor will
move in its housing. If it's absolutely bound up tight in there with
rust you could drive the shaft right down through the
armature. Heating the housing with a blow dryer will no doubt help
in that case, along with penetrants.
Once you've established that the motor will move without undue force,
drive it down so the impeller is resting on the housing. Now if a
small boy is handy station him with his hand under the motor. If not
then tune your senses to the squeaking point. In either case make
sure that the motor has clearance to fall through the vise without
fouling anything. Drive harder and shift the impeller. As you get
close to the disengagement point use gentle taps until you can gently
wiggle the impeller off while supporting the motor -- dropping it
end-first on the concrete may not kill it but it certainly won't
improve it and will probably dislocate the shaft. If you're using
the short pipe stuffed with rags method then it can fall on the rags.
Replacement - Align motor and insert by hand as far as possible. If
necessary support housing on open vise jaws and use a socket to drive
the motor in - do not strike the shaft. Since the impeller's not
covering things you'll be able to see when the motor is seated. Put
on the spring clips so you don't forget and to make sure they line up.
Now set the motor *shaft* on the vise anvil or other hard/heavy
object and drive the impeller on to the same depth it was
before. Don't overcook it -- if you go too far you'll have to go
back to step one and drive it out a bit.
Clip the case back together and check the clearance between the case
lip and impeller.
Before you button up the heater box, run the blower on all three
speeds -- it should purr like a kitten.
Yrs,
d