AC refurb - Sanden and other new components

Gary Knox

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I just completed refurbishing the AC system for my '74 CS. A good friend is a retired mechanic with AC certification, so we did it together, using R-12 that I had. I'm delighted, as the system works perfectly and produces air at the console in the mid-30's F.

Purpose of this post is to help anyone else who may be contemplating this conversion. I replaced everything in front of' the tubes coming out of the firewall new. I've developed a one page document of all the materials I used, along with sources I used or possible alternatives (i.e. for the authentic Sanden compressor which I bought as a close-out). I also have about 25 close-up/detailed pictures of the mounting bracket (used OE that was on the Bosch compressor), minor modifications it needed, and what the components look like in the completed installation.

IF you would like a copy of the materials and short summary of procedure, send me a PM with your e-mail address. I don't know how many pix I can send via e-mail, and I don't have a public pix storage spot, so we'll need to work out either CD/DVD or thumb drive for those.

Hope this can be helpful.
 
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steve in reno

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Gary I would appreciate this info.
This will be next winters project.

Pics can be resized to send via email.
Easy to change a 3meg into a 175kb, and free http://www.picresize.com/#
I am not a geek so there may be better ways for transfer of files.

thank you for this offer

steve
 

JFENG

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. I don't know how many pix I can send via e-mail, and I don't have a public pix storage spot, so we'll need to work out either CD/DVD or thumb drive for those.

Hope this can be helpful.

Gray,
Thank you for the parts list. Nice.
If you want help with the pics I can post them to Picassa or Photobucket for all E9 folks (with a password ="Knox" r something similar to help keep the riffraff away.

I'm sure others would also be willing to help Out similarly
 
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Gary Knox

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PLEASE - if you want the info, send me your e-mail address. Asking for it without the address just increases the effort required!!

THANKS for your consideration by following directions!! - ha.
 

Gary Knox

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Steve,

Thanks for your suggestion. I tried to do that, but the system stated it is 'an invalid file'. I have it in MS Word, and I thought that was acceptable.

Sorry - Guess I'm STILL a techno peasant in the 21st century!!
 

Gary Knox

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Here is the document - not easy to read here, unfortunately - had to copy and paste.

’74 BMW 3.0 CS with original air conditioning – refurbishment
Components:
Compressor: Sanden SD-510HD, ear mounts with 2 groove pulley:
Mount attached to engine was for a Bosch rotary compressor. Sanden fits on it with minor modifications. Tensioner bracket fits as well.
Belt is ½” X 31” Kevlar reinforced.
AP Air Inc. Is possible supplier of ‘real’ Sanden compressors. Their part # is: 509 416

Receiver Drier: Approximately the same size as OE – bought from BusPartsExperts.com
Part # BPE 2695 (sight glass and port). Slightly larger diameter, required larger hose clamps
to attach.

Condenser: Parallel condenser, Universal Air Conditioners Inc. Part # CN20015XC
Quarter inch aluminum plate/ six rubber cushioned bolts for 3 mounting points. Refrigerant: Freon R-12
-------------------------------------
Hoses & couplings:

#10 connectors and hose connected to evaporator output tubing at rear of engine bay to low
side port. Also from port to compressor inlet. 135 degree connector at compressor,
hose coming out to rear and right side.

#8 connectors and hose from compressor outlet to top of condenser – 90 degree connector on
both ends.

#6 connectors and hose from bottom of condenser (straight connector) to receiver drier inlet
(90 degree connector at receiver/drier inlet)
#6 connectors and hose from receiver/drier outlet (straight connector) to high side port, and
from port to input tubing for evaporator at rear of engine bay.

Procedure:
Fitted all components and hoses/connectors, double checking length measurements before cutting hose. Used PVC tubing cutter to cut hoses. “Clocked” the hoses with connectors by marking both components with Sharpie marker (silver on black hoses, black on silver connectors) to maintain correct orientation when installed. Crimped ferrules on tubing in clocked position for hoses with AC hose crimper.

Connected 5 CFM vacuum pump to system via R-12 gauges and pumped for about 2 hours, obtaining 200-300 microns air pressure in system (high sensitivity vacuum gauge).

Installed some liquid R-12 in high side port, then vapor in low side port. After several hours, checked for leaks with extremely sensitive Freon sniffer. Found none, so started car and operated AC system until sight glass bubbles gone (2 lbs required), then added another 6 oz of R-12.

Center console outlet air at full blower speed and 1500 rpm engine speed was <35 degrees F.
 

bill

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Gary: I like the idea of keeping the OE evaporator (cheap.) Is there a valve of some sort that has to be cleaned, behind the evaporator?
 

Gary Knox

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  • We purged the evaporator system with the 'official' AC cleaning fluid and compressed air. Did not remove the valve at the evaporator. Too 'lazy' to remove all the stuff needed to get the the valve!! Thankfully, it all works good.
 
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