veduta

No. The additional hardware is all part of securing the new bracket to the original compressor mount. The 3 bolts that secure the mount are still there along with the adjustment bolt. Tension is adjusted just as it was before.

If all goes well tonight it goes in for charging tomorrow. I'll get to find out if I did it correctly! I'll let you all know the results. Fingers crossed!

Karrera Coupe

@veduta how is your installation going? Apologies for asking. Thanks in advance.

veduta

Sorry to all for those of you awaiting the conclusion of this self inflicted AC journey. Here is an update. Two weeks ago I completed all of the wiring under the deck lid as well as the installation of the three additional interior vents. I then double checked all of the hoses and connections in preparation for our first charge of the system. Good thing I did as I found I had missed an O-ring at the connection to the evaporator! I washed the car and headed to the shop after the car had basically not been off the jack stands for a month. A few miles down the road and a terrible squealing and screeching from the engine had me pulling over immediately. This was accompanied by the appearance of illumination on the dash for the alternator warning light. No issues with the belt upon examination so I turned around and headed for home with a heavy heart certain that I had somehow done something wrong to cause this issue. The terrible noise quickly started again and in an abundance of caution I decided to pull over and call AAA for a tow. I had it brought to my mechanic as in my mind I had done something terrible and didn't want to risk causing more damage, better safe than sorry when it comes to these cars and my limited experience.

As it turns out it was failure in the alternator bearing shaft and was purely coincidental and unrelated to my AC work so a new alternator and a lighter check book and I was on my way! My mechanic is not set up for anything AC related beyond much more than a charge and I had intended to take it to a local AC specialty shop with a great reputation in Cape Coral. I got it down there and dropped it off and headed to work with the help of the wifey. I sat biting my nails all day waiting for word from the AC shop and when I got the call I held my breath. Sure enough the report was the system will not hold pressure. AArrgghh!! He offered to charge the system to see if he could identify where the leak was and I approved. He called back a few hours later and told me he could hear hissing coming from Evaporator box and no where else. He didn't want to open the box and I knew it would be much easier for me to do it so I told him I would be by after work. AArgghh! I picked it up last night and opened the box and removed the evaporator. Sure enough there were two pin holes in one of the alluminum tubes! I don't know how it happened or how I managed not to notice it when I installed it but I was so focused on reading the instruction book and following directions that I did not take a good look at the unit before I installed it. I emailed Charlie at Griffiths and sent him some photos and he graciously offered to replace it if I send it back to him. He truly is a good guy and stands behind his product. If there is a chance it came like that from the factory and the defect was missed he wasn't going to take a chance and he is sending me a new one. I will have the new evaporator next week but we will be out of town the following weekend so I may not have another chance to install it and take it for charging before the Fourth of July, but as soon as I do I will be back to share the results! Cheers!

Keith Guidus

Many thanks for the update! Keep it up!

Steve Dawson

Good news about Griffiths standing behind his product. Sounds like his good reputation is well-deserved. Thanks for the updates, this is great information for those of us contemplating A/C upgrades. Good luck with the install.

RE: alternator
I experienced a similar failure last month. Turns out the "tolerance ring" (a cheap plastic disk that centers the bearing in the non-fan end alternator housing) cracked and fell out. This allows the end of the rotor to wobble around and make contact with the stator windings, which makes an awful noise and destroys the windings. Classic case of a $2 part failing and destroying a $xxx part. I took mine to an alternator repair shop and they deemed it unrebuildable, so I ended up buying a replacement rebuilt unit.

veduta

Steve, Bingo on both points. It was the ring for me as well. I didn't know for sure at the time what the problem was and that noise was really scary! I'm glad I gave it to my mechanic because the new one came with an internal voltage regulator and the old one had to me removed and some wiring modified and I'm not confident doing any procedure without really good documentation.

Karrera Coupe

Thanks @veduta for the update. I am learning from you vicariously!
Good luck. Your coming down the final straight and the checkered flag of cool air awaits.
I am eagerly awaiting the happy ending that you will hopefully share with the rest of us, the owners of spring and fall only air cooled 911s.
Cheers

veduta

Quick update for those who might be interested. I installed the replacement evaporator from Grifiths ( Thanks Charlie! ) and brought it in for it's initial charge. I went with a shop that specializes in nothing but Auto AC and had a lot of great reviews. I handed of the detailed instructions for charging but I could tell the owner of the shop likely wasn't going to look at them at all but I rolled the dice. Picked up the car in the afternoon with the report that temps were blowing from the vents in the 50's but it just didn't feel like it was getting as cool as it should. I picked up vent thermometer and I read 60 degrees from the vents but it did drop down into the high 50's after about 15 minutes on a 91 degree day. I know plenty of members like Pavegeno are getting temps in the 30's and 40's so I'm confident I can do better. I checked with the AC shop who charged the system and was told he put in about a "pound and a half" of refrigerant and Charlie's instructions say to start with 36 ounces so I suspect that's the real problem. I spoke with Charlie about it and he suggested I double check that the thermostat is working properly and that I have a good understanding of what the freeze point is so I can manage the thermostat and prevent the evaporator from freezing up in this ridiculously humid climate. He said "Let's check all of our stuff before we go back to the shop to check theirs" so that's what I'm doing this weekend. I also picked up a set of AC test gauges from Harbor Freight so I can check and record the HS and LS pressures which will also tell me more. It's difficult to find good quality shops down here in SW Florida and I'm reluctant to return to the same shop so once I check pressures, I may choose a different shop but I'm hoping to get this all wrapped up and chilled out by next week.

I can tell you that even with vent temps in the high 50's it was a night and day difference from before. I can drive in the summer on the hottest of days and not be sweating from everywhere. Sorry the saga is getting so long but I'll hopefully be delivering my final update next week. Fingers crossed (again)!

Keith Guidus

Can't wait!

Pavegeno928

make sure they had the deck lid down when they were putting in freon. If the engine lid was up the suction of the engine fan pulling air across the rear condenser would be non-existent thus driving temps and pressures up resulting in them not adding enough freon.

maybe as simple as connecting your gauges with the engine lid resting on the hoses to accurately see what is going on.

Good luck!

Pavegeno928

still getting low 30s out of the vents in 90+ temps. Good luck!

crracab

Your system is undercharged. You should start with at least 36oz. of R-134. My system has this charge and I get low 30's temps at the center vent in central Florida at idle, in full sunlight when the ambient temp is in the high 90's. When I took the car to the shop for its initial charge the tech was reluctant to put enough refrigerant in the system because the high side pressure was climbing. I pointed to the sticker in the engine compartment which states that the factory filled the system with 47.6oz. of R-12, that the new system with two additional condensers is bigger, and that the engine lid was up. Start with 36oz. and adjust up or down until you get temps in the low 30s.

ljpviper

Any update, did you finally sort out the final issues?

veduta

Hi Ljp, Honestly I'm not experiencing the same success as some of the other guys here. It's a complicated charging process and I'm still trying to get it sorted out. Here is where I'm at. After getting vent temps in the upper 50's on a 90 degree days I bought my own set of gauges and tested the pressures for myself. All instructions that I can find say that to test the pressure you need to turn the thermostat to the highest setting and the fan on the highest setting. When I do that with the engine at idle I get a low side pressure in the high 50's and a high side pressure around 225 which would indicate enough refrigerant. With the thermostat all the way and the fan as high as it goes I am only getting vent temps in the high 60's low 70's but with the thermostat dialed down to the freeze point and the fan on 2 I get temps in the low 50's which is really pretty good but nowhere as good as others. In traffic on a 90+ degree day I'll get temps in the 60's.

I took it back to the shop and then got the same readings and came to the conclusion that there is enough refrigerant. They even removed the refrigerant and put it under vacuum for 10 minutes and then re-charged and the system took roughly 24 ounces before High side pressures went up between 225 and 250 and they felt as though that was right on the edge of adding too much. Made sure they knew to measure with the deck lid closed and they did. Same performance with Vent temps after that. If I could maintain vent temps in the low 50's I would be fine with that, ecstatic even but were not there yet. I think potentially the next move is a different shop and asking them to put it under vacuum for an extended period of time and then slowly start to fill again and see where we can get it. I don't know why it will only take 24 ounces when the Griffiths manual says to start with 36. I haven't given up yet but still trying to figure out where to go with it.

veduta

One of the reason why it is confusing is the instructions for the thermostat. The manual says to perform an ice water test with the probe to determine the freezing point of the thermostat so you can prevent the evaporator from freezing up. The test revealed the freeze point is very shortly after the compressor engagement, maybe only a quarter of a turn. If I run the system just below the freeze point I get vent temps in the 50's depending upon the ambient conditions and I'm pretty happy with that. The High side pressure under those circumstance are lower and might indicate room for a little more refrigerant but perhaps not opening the thermostat all the way skews the test. I think a different shop willing to follow the instructions to the T and recording everything is my next step. If after that nothing changes then I will accept that this is just as good as it will get for me.