Underfilling A/c

[jdnet]

Hey guys,

Got a question. I had a new plate and bearing put on my a/c compressor a couple of days ago. After the repair I was informed that I didn't have any refrigerant in the system. Althhough a week before I had the system check and the pressure was good. So something had to go wrong during the repair. The compressor wasn't removed nor was the gas evacuated so my only guess was they got the valve stuck while checking pressure.

Basically my problem is that I don't want to have everything removed to pressure test the system as it will probably leave me with more pains than I have already. So here's the thing. I was thinking dof putting about a Rs. 1000 is refrigerant and checking the pressure for a few days. A thousand would mean that the gas is less than half it should be. If the pressure hold up I would add more to bring it to the correct level.

Is this acceptable or do I just need to get everything taken off the car and worry about replacing more things that would inevitably need replacing?

[The Don]

Hey guys,

Got a question. I had a new plate and bearing put on my a/c compressor a couple of days ago. After the repair I was informed that I didn't have any refrigerant in the system. Althhough a week before I had the system check and the pressure was good. So something had to go wrong during the repair. The compressor wasn't removed nor was the gas evacuated so my only guess was they got the valve stuck while checking pressure.

Basically my problem is that I don't want to have everything removed to pressure test the system as it will probably leave me with more pains than I have already. So here's the thing. I was thinking dof putting about a Rs. 1000 is refrigerant and checking the pressure for a few days. A thousand would mean that the gas is less than half it should be. If the pressure hold up I would add more to bring it to the correct level.

Is this acceptable or do I just need to get everything taken off the car and worry about replacing more things that would inevitably need replacing?

I'm not sure why you will need to have everything removed to pressure test the system. My main concern at this point is not the lack of refrigerant but the possible lack of lubrication for the compressor as I think in most systems the compressor oil is added along with the gas and if there is a release of the gas you can usually assume the lubrication oil would have disappeared too.

If there is no gas in the system, why don't you simply fill the system up with Nitrogen and do a pressure test and if that holds fill the system up again with gas and lubricant run for a few days and test again. This sounds too obvious, and I would have assumed this would have occurred to you already so what did I miss?

[jdnet]

yeah air conditioning is not really my strong point to be honest. I can barely figure out what's wrong with the a/c in my room, much less a car. The last problem I had with an a/c got sorted out by dumping a can of that no leak stuff that you can find at auto parts stores. Anyway I took it down to a garage that list member vvti suggested and we did do a pressure test. Wasn't holding pressure. No leaks in the obvious places so it's either a leak at the evap core or it's a overheating compressor. I really wish it's the evaparator core. So both the parts will need to come out on friday for testing. I'd hate for it to be the compressor that I just had repaiired.

[The Don]

yeah air conditioning is not really my strong point to be honest. I can barely figure out what's wrong with the a/c in my room, much less a car. The last problem I had with an a/c got sorted out by dumping a can of that no leak stuff that you can find at auto parts stores. Anyway I took it down to a garage that list member vvti suggested and we did do a pressure test. Wasn't holding pressure. No leaks in the obvious places so it's either a leak at the evap core or it's a overheating compressor. I really wish it's the evaparator core. So both the parts will need to come out on friday for testing. I'd hate for it to be the compressor that I just had repaiired.

I see. Well things kind of depends on the sophistication of the testing chaps. Now there are electronic devices that can help pin point a leak but sensing leaking gas. I am yet to see one in any AC shop I have been to but then the chaps I use are hardly sophisticated. The other method is simply to pressurise the system with Nitrogen and use the soap bubble technique on the joints etc.

You can also isolate the compressor completely if they have bits (stoppers) that go at the end of the lines that seal the lines and help them isolate a section to test for a leak. If the evaporator is accessible then its not too difficult to get out for a leak test. In some cars this requires the dashboard to be taken apart.

The other usual culprits are the seals between the evaporator and the lines inside the engine bay, the condenser and the seals between the lines and the compressor. But it sounds like the obvious ones have already been ruled out.

I'd hate it to be the compressor too, as evaporators you can replace with generic units but the compressors, you need to find an original replacement and this is becoming more difficult....

[harshansenadhir]

Nitrogen pressure by sections would be the way forward. Even the evaporator you can pressure test without taking the dash apart (in most cases).

Fair to suspect the compressor as it was the item which was repaired. Few tricky points where pressure test might fail

1. If the leak is from the high / low gas charging nipples / valves then its difficult to diagnose as pressure gauge will be attached to the system through these valves.

2. There are leaks inside the compressor where leaks only materializes when the compressor rotates. Standstill it won't leak.

Personally I'd prefer a leaky compressor than evaporator as it spares the trouble of taking the dash apart which is a hassle and most makabasses don't know to remove / refix a dash properly.

[CARBON B4]

I see. Well things kind of depends on the sophistication of the testing chaps. Now there are electronic devices that can help pin point a leak but sensing leaking gas. I am yet to see one in any AC shop I have been to but then the chaps I use are hardly sophisticated. The other method is simply to pressurise the system with Nitrogen and use the soap bubble technique on the joints etc.

Noticed you are in Nugegoda, so where do u normally go for a/c stuff ? I usually go to ATCO on Stanley Thilakerathne, guys are pretty good and seem to know what they are doing.

[The Don]

Noticed you are in Nugegoda, so where do u normally go for a/c stuff ? I usually go to ATCO on Stanley Thilakerathne, guys are pretty good and seem to know what they are doing.

I go to a chap located in Kohuwala who was recommended to me by a friend. But to be honest I am not totally satisfied with the work which was sadly done in my absence. Now my car has a little problem which some JDMs have that the condenser was a little small and the evaporator also developed a leak and both were replaced. But still the cooling isn't great in the hot sun. Part of the problem is the rotary compressor which seems to only develop good compression above 2000 rpm, so I am not entirely sure what to do about it.

ATCO is very close to where I live though I haven't use their services. I did use Custom auto AC once and while I had issues with the job they did (unnecessary replacement of bits that did not need replacing) I can't say they were that bad in terms of the work they did, but again there was inadequate cooling in the hot sun.

I wonder if the problem is the crappy malaysian or thaiwani evaporators they fit because I've never been able to get an AC fixed properly. Any ideas?

[CARBON B4]

Part of the problem is the rotary compressor which seems to only develop good compression above 2000 rpm, so I am not entirely sure what to do about it.

ATCO is very close to where I live though I haven't use their services. I did use Custom auto AC once and while I had issues with the job they did (unnecessary replacement of bits that did not need replacing) I can't say they were that bad in terms of the work they did, but again there was inadequate cooling in the hot sun.

I wonder if the problem is the crappy malaysian or thaiwani evaporators they fit because I've never been able to get an AC fixed properly. Any ideas?

If the a/c is cooling only at high revs, chances are your compressor is having some issue. So running it like that will make it worse and u many need to replace the entire unit. If the car is parked in the hot sun ,always put the shutters down to let the hot air out , it will put less strain on the a/c system. You might see an improvement in cooling. Another thing would be the 3M clear tint for the windscreen, the dash is what gets heated up the most so the a/c needs to work its ass off to cool it. One guy in office got it done any says there is a significant improvement in cooling.

Anyway try out ATCO, so far I dont have any complaints about them...

[The Don]

If the a/c is cooling only at high revs, chances are your compressor is having some issue. So running it like that will make it worse and u many need to replace the entire unit. If the car is parked in the hot sun ,always put the shutters down to let the hot air out , it will put less strain on the a/c system. You might see an improvement in cooling. Another thing would be the 3M clear tint for the windscreen, the dash is what gets heated up the most so the a/c needs to work its ass off to cool it. One guy in office got it done any says there is a significant improvement in cooling.

Anyway try out ATCO, so far I dont have any complaints about them...

Well in terms of my first car, it has nothing to do with the compressor as the compressor was changed to a piston type to improve compression. The whole system was replaced yet satisfactory cooling wasn't achieved (This was custom auto AC). I actually regretted changing the compressor as a piston type compressor is heavier on the engine.

In my current car again everything was changed apart from the compressor, and the compressor was checked and seems to be delivering satisfactory compression on reves higher than say 1500, yet under the hot noon sun, unsatisfactory. I must add the car is black as well which doesn't help. Before I do anything I want to get to the bottom of why this is the case.

[CARBON B4]

In my current car again everything was changed apart from the compressor, and the compressor was checked and seems to be delivering satisfactory compression on reves higher than say 1500, yet under the hot noon sun, unsatisfactory. I must add the car is black as well which doesn't help. Before I do anything I want to get to the bottom of why this is the case.

I think the color thing has very little effect, its true that light will reflect back on white/silver surface but the impact maybe not much. A lot to do with the size of the windscreens, as this is the main place where heat enters the car.

When I had a Honda EK3 had the same kind of issue, the guys at Atco said the factory condenser was small, and did not do well in our heat. So I fixed a bigger condenser and I think the fan was also changed. There was a noticeable difference.

The B4 is also not that great in the scorching sun, I only drive in the morning and evening and the car is parked under a shed

[jdnet]

Nitrogen pressure by sections would be the way forward. Even the evaporator you can pressure test without taking the dash apart (in most cases).

Fair to suspect the compressor as it was the item which was repaired. Few tricky points where pressure test might fail

1. If the leak is from the high / low gas charging nipples / valves then its difficult to diagnose as pressure gauge will be attached to the system through these valves.

2. There are leaks inside the compressor where leaks only materializes when the compressor rotates. Standstill it won't leak.

Personally I'd prefer a leaky compressor than evaporator as it spares the trouble of taking the dash apart which is a hassle and most makabasses don't know to remove / refix a dash properly.

Sorry was busy the last few days. So didn't get a chance to reply or get the problem fixed till today. Anyway it's solved. Basically the compressor was leaking out of every seal and o-ring. The compressor itself was in top shape though so I had all the seal and o-rings put in. The funny thing was that each time they fixed one leak, a new and completely different leak popped up.

The temp reading at the vent reaches 4 c before the compressor shuts off so it should be good.

I like the fact that I could keep my compressor instead of putting in some used one that I know nothing about.

Anyway it goes to show that some compressor problems can be fixed if you find the right guy for it.

[The Don]

Sorry was busy the last few days. So didn't get a chance to reply or get the problem fixed till today. Anyway it's solved. Basically the compressor was leaking out of every seal and o-ring. The compressor itself was in top shape though so I had all the seal and o-rings put in. The funny thing was that each time they fixed one leak, a new and completely different leak popped up.

The temp reading at the vent reaches 4 c before the compressor shuts off so it should be good.

I like the fact that I could keep my compressor instead of putting in some used one that I know nothing about.

Anyway it goes to show that some compressor problems can be fixed if you find the right guy for it.

Who did you utilise for the job?

[harshansenadhir]

Sorry was busy the last few days. So didn't get a chance to reply or get the problem fixed till today. Anyway it's solved. Basically the compressor was leaking out of every seal and o-ring. The compressor itself was in top shape though so I had all the seal and o-rings put in. The funny thing was that each time they fixed one leak, a new and completely different leak popped up.

The temp reading at the vent reaches 4 c before the compressor shuts off so it should be good.

I like the fact that I could keep my compressor instead of putting in some used one that I know nothing about.

Anyway it goes to show that some compressor problems can be fixed if you find the right guy for it.

Good to know that it was a happy ending though it can be bitch to find out where exactly the leak is.

Very well said about the repairing of compressors rather than replacing, contrary to the popular belief.

[jdnet]

Who did you utilise for the job?

place in pepiliyana recommended by vvti.