Help with priorities please...mech work : )
08-31-2011 | 08:50 AM
#16
Three Wheelin'
Joined: Sep 2003
Posts: 1,526
Likes: 0
From: SF Bay Area
I do not remember where I got mine. I think is is probably a single stage pump but I could be wrong. I do know it evacuates the system in no time. Here is the one Harbor Frieght has
http://www.harborfreight.com/25-cfm-...ump-98076.html
I got my gauge set at Harbor Freight.
http://www.harborfreight.com/a-c-man...source=linking
Here is the adapter
http://hires.amazonwebstore.com/FJC-...source=froogle
http://www.harborfreight.com/25-cfm-...ump-98076.html
I got my gauge set at Harbor Freight.
http://www.harborfreight.com/a-c-man...source=linking
Here is the adapter
http://hires.amazonwebstore.com/FJC-...source=froogle
08-31-2011 | 10:41 AM
#17
Rennlist Member
Joined: Sep 2007
Posts: 12,155
Likes: 371
From: Johnson City, TN
Agree, AC work is much easier than expected. Did a 928 and a Benz, plus have been hanging around a shop watching.
I shopped around and found that NAPA also has Mastercool Gauges (high quality/brass body) for less than $100. Flush gun $80. Shrader valve removal tool $10.
Then, HF 2-stage vac pump $120
Observation --
928 O-ring kits were short / need to do all O-rings / insist on all / buy a few kits / ones at NAPA are too thick or too thin.
Flushing evaporator was difficult due to access. Need to use some sort of hose attachment or rig to butt up against pipes.
Flushing is a potentially dangerous activity. I liked it, though. 100 PSI. Empties the reservoir very fast. Expensive flush from napa $32 per quart --- good because it blows and dries moisture and lots of old oil and old leak trace out.
Expansion valve needs to be replaced, drier, O-rings, compressor-entry O-rings (not in kit), fuel cooler O-rings (not in kit).
I shopped around and found that NAPA also has Mastercool Gauges (high quality/brass body) for less than $100. Flush gun $80. Shrader valve removal tool $10.
Then, HF 2-stage vac pump $120
Observation --
928 O-ring kits were short / need to do all O-rings / insist on all / buy a few kits / ones at NAPA are too thick or too thin.
Flushing evaporator was difficult due to access. Need to use some sort of hose attachment or rig to butt up against pipes.
Flushing is a potentially dangerous activity. I liked it, though. 100 PSI. Empties the reservoir very fast. Expensive flush from napa $32 per quart --- good because it blows and dries moisture and lots of old oil and old leak trace out.
Expansion valve needs to be replaced, drier, O-rings, compressor-entry O-rings (not in kit), fuel cooler O-rings (not in kit).
08-31-2011 | 11:07 AM
#18
Racer
Joined: Aug 2011
Posts: 324
Likes: 0
From: Fayetteville AR
** Laughs ** - No it won't. By the time you finish fixing one thing something else will go wrong.
BTW A/C is not that complicated. I think many avoid learning about A/C because it seems technical. Arizona A/C has the correct rebuild kits for the compressor and the o-rings for the connections. They sell a crimp kit and barrier hose so you can make your own hoses. They sell a blue bubble solution that is very good for finding leaks.
While it is necessary to trouble shoot the A/C to see what is wrong - the rest is almost predicable. The clutch has a bearing that is replaceable and sourced from other than Porsche for very little money. Harbor freight sells a set of gauges and a vacuum pump. The gauges can be adapted to the R12 system with a small adapter that can be had on the Internet for a couple of bucks. R12 can be found on Craig's list for a reasonable amount. If smoke was coming off the compressor it is probably from a belt slipping suggesting it is more than the clutch and the compressor has frozen. Then again you do not know until you look at the whole system.
In many ways it is just a matter of going through a 20+ year old system and reubuilding it. For the price of a shop doing the job one time you can buy the tools to do the job. Get a good book on A/C first. I went to a local shop and talked the guy into letting me watch him working on a few systems. Cost - a bag of Butter Fingers candy bars.
BTW A/C is not that complicated. I think many avoid learning about A/C because it seems technical. Arizona A/C has the correct rebuild kits for the compressor and the o-rings for the connections. They sell a crimp kit and barrier hose so you can make your own hoses. They sell a blue bubble solution that is very good for finding leaks.
While it is necessary to trouble shoot the A/C to see what is wrong - the rest is almost predicable. The clutch has a bearing that is replaceable and sourced from other than Porsche for very little money. Harbor freight sells a set of gauges and a vacuum pump. The gauges can be adapted to the R12 system with a small adapter that can be had on the Internet for a couple of bucks. R12 can be found on Craig's list for a reasonable amount. If smoke was coming off the compressor it is probably from a belt slipping suggesting it is more than the clutch and the compressor has frozen. Then again you do not know until you look at the whole system.
In many ways it is just a matter of going through a 20+ year old system and reubuilding it. For the price of a shop doing the job one time you can buy the tools to do the job. Get a good book on A/C first. I went to a local shop and talked the guy into letting me watch him working on a few systems. Cost - a bag of Butter Fingers candy bars.
09-01-2011 | 06:08 AM
#19
Three Wheelin'
Joined: Sep 2003
Posts: 1,526
Likes: 0
From: SF Bay Area
http://www.ackits.com/
They have kits with the green seals that fit the 928 and sell most supplies you would need.
They have kits with the green seals that fit the 928 and sell most supplies you would need.
09-01-2011 | 06:15 AM
#20
Three Wheelin'
Joined: Sep 2003
Posts: 1,526
Likes: 0
From: SF Bay Area
I have to admit I am confused on this flushing thing. I have never done it and read in a few places where it is generally not needed. If you flush the system then you would need to add oil. I have again been confused as to how much oil the 928 system takes. The bigger problem is how much oil to add if you just flush out the condensor.
The system I have for retrieving the freon has a oil collection cup that is used to measure the amount of oil removed with the freon. This amount is to be added back to the system before charging. I assume when you rebuild a compressor you keep track of the oil drained to replace it.
Nothing I have read clarifies the amount of oil issue.
The system I have for retrieving the freon has a oil collection cup that is used to measure the amount of oil removed with the freon. This amount is to be added back to the system before charging. I assume when you rebuild a compressor you keep track of the oil drained to replace it.
Nothing I have read clarifies the amount of oil issue.
09-01-2011 | 08:54 AM
#21
Rennlist Member
Joined: Sep 2007
Posts: 12,155
Likes: 371
From: Johnson City, TN
I found conflicting information on oil. 350ml ref in WSM, seemingly restated as 280ml in a later service bulletin. Filled our 86 with 350ml and the right amount of R12, but it doesn't get quite cold as expected and seems to mirror the symptoms of Worf's thread (he realized he had oil overfill), though he didn't quantify it fully.
To get the level correct I think one has to remove fully.
One AC site talked about "black death" from oil breakdown and suggested that ac oil change was a missing piece of automotive maintenance, such that system life would extend if oil were changed.
Am still learning.
To get the level correct I think one has to remove fully.
One AC site talked about "black death" from oil breakdown and suggested that ac oil change was a missing piece of automotive maintenance, such that system life would extend if oil were changed.
Am still learning.
09-02-2011 | 06:02 AM
#22
Three Wheelin'
Joined: Sep 2003
Posts: 1,526
Likes: 0
From: SF Bay Area
I found conflicting information on oil. 350ml ref in WSM, seemingly restated as 280ml in a later service bulletin. Filled our 86 with 350ml and the right amount of R12, but it doesn't get quite cold as expected and seems to mirror the symptoms of Worf's thread (he realized he had oil overfill), though he didn't quantify it fully.
To get the level correct I think one has to remove fully.
One AC site talked about "black death" from oil breakdown and suggested that ac oil change was a missing piece of automotive maintenance, such that system life would extend if oil were changed.
Am still learning.
To get the level correct I think one has to remove fully.
One AC site talked about "black death" from oil breakdown and suggested that ac oil change was a missing piece of automotive maintenance, such that system life would extend if oil were changed.
Am still learning.
