Automotive Air Conditioning Information Forum (Archives)

steven on Wed June 16, 2010 1:56 PM

Year: 1986
Make: porsche
Model: 944
Engine Size: 2.5
Refrigerant Type: r-12
Ambient Temp: 88
Pressure Low: 0
Pressure High: 175
Country of Origin: United States

Just got my a/c up and running but only cooled for a few days (r-12 system that was empty for at least 7 years). New receiver/drier and compressor. No leaks. When system stopped working after a few good days of cooling, low pressure was 0, high side, 175. I'm in the process of replacing the expansion valve and will flush the rest of the system this time.

No debris in the the expansion valve when I removed it (I was assuming it was stuck but realize I may have debris elsewhere that I'll look for when I flush). The old expansion valve had a small rubber insert that fell into the engine bay somewhere. New one doesn't have it. How important was the little rubber insert (looked like a small rubber reducer, about 3/4" long that fit into the smaller diameter tube of the valve-inlet?)

Thanks
Storch
1986 porsche 944

http://www.autoacforum.com/forumimages/expansionvalve.jpg

HVargas on Wed June 16, 2010 3:50 PM

Does the gauge move off 0 at all or just sit still? Small chance it could just be that your gauge's aren't depressing the valve. More likely though your expansion valve is bad. That would be the first place I would start. Remove it and see if you can blow through it. Do you have a picture of the new and old expansion valve as well?

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: Arizona Mobile Air

steven on Wed June 16, 2010 4:31 PM

I was able to blow through it. I did put a stock pic on the previous post but didn't do it correctly. Here it is:

The rubber insert fit into the smaller diameter threaded section (inlet). Can't find the insert on any parts diagrams for the car. Wonder if it is really necessary or could have even been part of the problem blocking the valve?

Edited: Wed June 16, 2010 at 4:52 PM by steven

ice-n-tropics on Thu June 17, 2010 9:15 AM

Rubber insert is a sealing shipping dust cap and is intended to be discarded
Cordially,
hotrodac

-------------------------
Isentropic Efficiency=Ratio of Theoretical Compression Energy/Actual Energy.
AMAZON.com: How To Air Condition Your Hot Rod

steven on Thu June 17, 2010 9:52 AM

Don't think it's a dust cap... it is a tapered rubber insert / sleeve. Also, it was in the expansion valve inlet when I removed the valve from the car (it's the factory installed valve.

I'm just not sure whether to install the insert with the new expansion valve or just leave it out. Hoping for some input from those who have installed this type of valve before.




Edited: Thu June 17, 2010 at 2:36 PM by steven

steven on Fri June 18, 2010 10:06 AM

Edited: Fri June 18, 2010 at 10:13 AM by steven

steven on Fri June 18, 2010 10:12 AM

Flushed the system this morning...all went well, nice and clean, no blockages or gunk. Went to install the EV and turns out the part I have is the mirror image of the stock part and won't fit (the smaller diameter inlet is in the location where the larger diameter outlet is and the hard lines won't flex and I'm not forcing it).
I was just going to delete the rubber sleeve/insert from the old valve since the new one didn't come with it and no parts diagrams show it for my vehicle.

In looking for a suitable valve, local parts houses list a block style expansion valve. Can I use that as a replacement? How would I deal with the extra inlets/outlets.

Storch



Edited: Fri June 18, 2010 at 10:19 AM by steven

bohica2xo on Fri June 18, 2010 12:12 PM

I would ignore the mystery part if replacing the valve. Consider it part of the old assembly.

As long as the replacement valve you do install has a proper seat for the O ring, and seals well you are good to go. If the replacement valve you have has the wrong connections, don't install it. There is a proper flow direction for the TXV, some even have arrows forged into the body.

The H type in your last picture will not work on your system. The "extra" ports are for the suction line, and this is how it senses suction temperature.

Your system would appear to be dealer installed A/C. The factory system that year did use the H block. The previous years ('83~'85) used a TXV similar to yours, BUT it had an external equalization line as well as the sensing bulb.

Matching your old valve up is the best bet. You need the same size lines & flow direction. Are all of your hose connections crimped, or are there some hose clamps in the system?

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

ice-n-tropics on Fri June 18, 2010 12:17 PM

Stephen,
The tapered sleeve rubber part doesn't belong in the TEV inlet. Maybe it came from upstream, e. g., a shipping plug from a prior receiver drier change or a hose liner failure.
The block valve would be a PITA to fab evaporator and hose line adapters with dubious benefit.
One of the strangest engineering things I ever saw on a Porsche was the following:
Some early years 944 had a short life compressor mounting bracket which lost it's fixation to the compressor and endangered steering control. Audi did a countermeasure which was a steel restraining cable to keep the compressor from falling into the steering column "U" joint when the bracket would fail.
hotrodac



-------------------------
Isentropic Efficiency=Ratio of Theoretical Compression Energy/Actual Energy.
AMAZON.com: How To Air Condition Your Hot Rod

steven on Fri June 18, 2010 2:21 PM

"Your system would appear to be dealer installed A/C. The factory system that year did use the H block."

That would explain why the local parts houses list the block style TXV. But the original factory parts manual shows the type that was installed and I photographed.

Oh well, found an online supplier who's photograph matched what I removed exactly. It's on order and should be installed next week.

Just wondering if that rubber sleeve was the cause of the blockage all along.

Thanks again.

Steven

Oh...all the a/c lines are oem crimped (no clamps).

bohica2xo on Fri June 18, 2010 2:52 PM

Steven:

A/C was sort of secondary to the euro car makers back then. Many times the A/C was installed at the dealer after it landed in the US with a kit from the parts department. Small changes may have been made along the way to use a different vendor part as well.

The FSM may be showing the older valve, which looks like the one you have. It did have a second line on it for the equalization port that may not be obvious in the FSM pictures. Your system may be a half step between the 85 & 86 model years, with no equalization - and not yet an H block.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

steven on Sun June 27, 2010 9:01 AM

Well. so far ordered what should be the correct Porsche replacement TXV but the same incorrect part keeps arriving by UPS. Any idea where I can source the correct part? The original is a Nippondenso. There are some #'s on the top: 047500-0630, ND 9E05 but google doesn't seem to be helping me out.

Steven

bohica2xo on Sun June 27, 2010 2:35 PM

Steven:


This is the valve Shown for the 1985.

The 1986 shows a block type valve.

You are showing pics of a TXV without external equalization.

At this point, you need to buy the part in person, and match up the size & type. Obviously the 944 you have is a mid-year change not covered in the books.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

jscholten on Wed June 22, 2011 10:02 PM

Quote
Originally posted by: steven


Steven, did you ever find a part that matched the 047500-0630 part number? I'm having the same problem trying to find the same part shape as the old part...the new ones are taller and will not fit. I may have found one on densoproducts.com...could not find the 0630 part but both 047500-0610 and 047500-0640 translate to part number 475-0101 which looks like the right part. Any suggestions are welcome...thx.

steven on Wed June 29, 2011 10:11 AM

Never did find it. Got a used one from a parts car locally. Denso told me that the part was custom made for Porsche and that I'd have to go to the dealer for the part.