AC Redo – Some Questions

[tirwin]

Originally Posted by Bob Kontak

Thought I was nuts. Wayne put new servers in this weekend.

Seeing your profile pic reminded that I got to shake the hand of the man this morning -- the one and only Vic Elford. I got him to sign my copy of his performance driving book. PCA had a coffee and cars event at PEC Atlanta and he was there with Bob and Cam Ingram and Bill Warner. They told some great stories. It was a blast.

[Irhmsd]

Originally Posted by tirwin

The convenience of a lift makes all the difference in the world for this kind of job. I'd say someone who knows what they're doing and doesn't run into something like a stuck hose fitting that wastes a bunch of time -- couple of hours to get them off and a couple of hours to get them on.

Thanks!

[kuehl]

Originally Posted by Irhmsd

How long should it take a knowledgeable porsche tech to replace all hoses in my 1974 with front and rear condensers?

8 hours is fair for a shop or a DIY; from the time you get the car up on jack stands to the end when you put your tools away. If you follow the logical directions and do not get side tracked looking at or fixing other issues not related to AC, 8 hours.
A lift does not save you that much time.
The LH front and RH rear tires need to come off.
Dirt falling down that has accumulated behind the hoses is the annoyance, so baseball cap, safety glasses, and a shop vac are needed.
For a DIY, floor jack and 4 jack stands get you where you have to go.
It's a weekend job.

[NY65912]

I just completed the Kuehl AC upgrade. Here's what I learned. I worked with the car on 4 good jackstands in a 1 car garage. I had 30" between the driver's side and the wall, 18" on the passanger side, 18" in front and if the garage door was closed 18" in the rear. I worked slow and methodical.

I replaced the evap, drier all hoses, front condenser, added the Duel Kuehl rear wheeelwell condensers and a new compressor in approx 24 hrs total time over 2 months.

The main pieces of advice are:
1 - READ the manual Charlie supplies and read it again. It is exact.
2 - Try to fish the new lines behind the windshield washer tank or if you remove it empty it! Trying to reinstall a full tank on my M491 car was not fun.
3 - Call or email Charlie with any question and he will promptly answer. I think he takes a little longer to answer smoke signals.
4 - Yes, it can be dirty, very dirty. Wear safety glasses
5 - Did I mention reading the manual?

Every thing becomes self explanitory as you go. One step at a time.

[tirwin]

Maybe I read the question too narrowly. I read it as asking a shop just to R&R hoses and nothing more. I estimated 4 hours of labor to do that. Maybe that's optimistic. A lift certainly isn't required.

For a DIYer that would be completely different and depends on what needs to be done in the process. I have a pair of cutters that have a wide mouth and they use a replaceable razor blade. They are super handy for this kind of job. (Note my system was bone dry.) I used those to make strategic cuts in a few places of the old hose. Basically I made cuts at the 4 corners of the tub and a couple of others places. Had he old hoses off in no time. Installing the new hoses was not bad either -- at least to me it wasn't the big deal some people have made it out to be. I have done far worse jobs in my Porsche ownership (replacing the headliner and replacing torsion bars comes to mind).

I probably spent the most time on installing the two wheel well condensers and the evaporator. I did the condensers separately while I had the engine out of the car so it's hard to say how long I spent there. Like others said though, reading the material ahead helps.

Overall, like Charlie said it's a good weekend project barring any unforeseen setbacks. I did have a setback with my old decklid condenser. Sourced a new one that blew a pinhole leak the first time it was pressurized. Had to wait on it's replacement. Had one flare fitting that really put up a fight. You can burn daylight on some of the dumbest little things. I repainted the protective cage after I pulled the old nose condenser. Some people don't get distracted by that kind of stuff but I do. There's an extra 30 minutes right there.

[rokemester]

Hope all is well with your project! We've had an unfortunate cold snap with a return of snow and road salt in NE Ohio.

[Ramp]

Originally Posted by rokemester

Hope all is well with your project! We've had an unfortunate cold snap with a return of snow and road salt in NE Ohio.

Thanks - My PC is down and I've been sidetracked but have been making progress.

Here's what's done. I have some pics now but more in a day or so when my PC is back up.

1. All new Griffiths hoses are in. Took about 6-7 hours taking my time. Probably took a pound of gravel off the car. I will still need to adjust them a bit once all components are back in so I can test fit. The hoses up over the front washer fluid canister in the driver wheel well are a pain - I had to remove the canister (easy) and put it back (hard). The line from the front drier under the driver-side back to the rear condenser is not too bad but feeding it through to the engine compartment from underneath was hard until we "lubed" the line.

2. New Khuel Front Condenser installed.

3. Rear Condenser flushed, cleaned and reinstalled.

4. New Khuel drier installed.

5. Evap flushed and cleaned. New Thermo Expansion Valve installed.

6. Evap blower baffle made per other Pelican posts.

7. Front condenser blower motor replaced and reassembled. New foam padding installed around base of front blower. Cleaned the blower area and battery grounds while in that area.

8. Bought a media blaster and cleaned off the steering rack skid plate, front condenser cage and front skid bar - ready for paint this weekend.

9. Compressor media blasted and cleaned. Clutch removed, inspected and cleaned up. The compressor and seals "seem" to be intact in good condition. no oil seepage showing. Still haven't decided on replacing it or keeping it. I used 2 cans (16oz) of Ester 100 Oil to "run through" the compressor; I know you can't flush. I added 4oz at a time to the compressor and then used a nut driver/drill to crank the compressor over until the oil was expelled. Repeat until the oil was "relatively" clean. I may do more but ran out of oil.

10. Made a new thermostat guide tube from copper tubing sourced at hobby shop for $1.59 (plus $7.00 for a flaring tool at HF). Still need to be installed. Q: The guide tube should be 1/2 way through the Evap - Correct ?

[rokemester]

Great progress! Thanks again for sharing your work. This thread will be so useful when I eventually address my AC.

[Discseven]

Originally Posted by Ramp

Last week took care of some small things -clean all grounds and battery terminals, started cutting a baffle for the Evap housing, put the front condenser blower with new motor/fan assembly back together, cleaned up the speed control and area, removed dryer, and took the clutch off the compressor.

Q: Take a look at the compressor - It was pretty clean and I didn't see and signs of leaking so I may juts put it back on - Thoughts ?

Attack mode!

(With compressor out Ramp, you might want to look at / replace shaft seal (if it has one.) A few bucks for the seal.)

[Ramp]

Originally Posted by Discseven

Attack mode!

(With compressor out Ramp, you might want to look at / replace shaft seal (if it has one.) A few bucks for the seal.)

I looked at all the seals once I had the clutch off and didn't see any obvious signs of seepage. I then de-greased and media blasted the compressor. The clutch bearing moves very smoothly and doesn't show any signs of wear. I haven't seen oil seepage from any seals so as of now I'm inclined to reinstall it and see what happens ! It's a gamble.

[kuehl]

You have gone the mile so why ponder the yard it will take to disassemble the compressor, inspect its pistons, bores, wobble plate and reed gaskets. If all looks good drop in a seal kit.

[Discseven]

Originally Posted by kuehl

You have gone the mile so why ponder the yard it will take to disassemble the compressor, inspect its pistons, bores, wobble plate and reed gaskets. If all looks good drop in a seal kit.

CG... is this the 10 hour project you mentioned when I was dealing with my system?

[Ramp]

Originally Posted by kuehl

You have gone the mile so why ponder the yard it will take to disassemble the compressor, inspect its pistons, bores, wobble plate and reed gaskets. If all looks good drop in a seal kit.

Haven't done this before but there's a first time for most things. Does anyone have a link to a good thread/article/etc. that has pics/details on this ?

[Ramp]

New Question:

There seems to be a baffle for the front condenser blower - see below. I don't have one and don't believe I need one. Thoughts ?

A/C Condenser Baffle Plate
Part #: 911-501-581-01-GRV-OEM

[mthomas58]

Originally Posted by Ramp

Haven't done this before but there's a first time for most things. Does anyone have a link to a good thread/article/etc. that has pics/details on this ?

Porsche 911 Nippondenso A/C Compressor Rebuild | 911 (1965-89) - 930 Turbo (1975-89) | Pelican Parts DIY Maintenance Article

[mthomas58]

Originally Posted by Ramp

New Question:

There seems to be a baffle for the front condenser blower - see below. I don't have one and don't believe I need one. Thoughts ?

A/C Condenser Baffle Plate
Part #: 911-501-581-01-GRV-OEM

The blower motor actually mounts to the baffle - I think you'll need one or need to fabricate one.

[Ramp]

mthomas58 - Thanks for the link !

It would appear that my 'baffle' is built onto the tub. From the parts diagram it looks like a separate component.

[mthomas58]

Originally Posted by Ramp

mthomas58 - Thanks for the link !

It would appear that my 'baffle' is built onto the tub. From the parts diagram it looks like a separate component.

OK looks like you're good to go!

[Ramp]

OK, need some advice on this part. I took the compressor mostly apart yesterday. I don't see any rough spots or flakes of metal. The oil was a bit dirty but I expected that since the oil drained from the rest of the system was close to black.

What am I looking for or at ?? The pistons go up and down smoothly with slight finger pressure. I'm thinking, clean, replace the o-rings and seal and put her back together.

Thoughts ?













Awesome Hatchet Porterhouse that evening - the hatchet bone was 20"

[kuehl]

You need to inspect:
1) Pistons for scratches and worn moly coating (grey black coating).
2) Cylinder Bores for scratches and 'chatter' marks.
3) Wobble plate (round aluminum disc on shaft) for grooves cut by piston
half bearings.
4) Shaft for rust or pitting wearing shaft seal rides.
5) Reed plate assemblies (aluminum plates, steel reeds, polymer (plastic like) coating
6) Thrust and needle bearings.

Wipe off the shaft. Hold it firmly with fingers of one hand. Gently tap the back section or case half with plastic mallet against the mount boss to separate the case halves; keeping the shaft with the pistons in the front section.

Inspect and provide pictures.