J30 A/C r134 fill valve'm not sure

[TetsuoK]

I need to fill the r134 in my '95 j30. It sat on a lot for about 6 months, and it all just sort of lost its charge.

I'm not sure where the fill valve is, though. There is what LOOKS to be the fill valve, a green capped one with an "H" on the cap. I thought this might be the high pressure fill.

In this case i'd want to fill it through the low pressure fill, but i'm not sure where it is.

The reason, also, why i wonder this, is because the adapter for filling it from the can of r134 does not couple with the fill valve. the fill valve on the infiniti is the exact same width as the coupling adapter, so it is not connecting to anything.

Has anyoen got a picture of it under the hood wheer i shoudl be filling it ?

[maxnix]

First, since it all leaked out and that has not been addressed, how will refilling help on the long term?

Second, if you cannot identify the correct valve, doesn't that give you some pause?

Third, since it has been exposed to the atmosphere for 6 months, that should tell you an evacuation and dryer replacement are required. How will you know the correct charge for the refrigerant and lubricant otherwise?

Finally, if you are not willing to replace the whole system after your experiments, I really recommend you take it to a professional AC technician and address the loss and seal problems before attempting a recharge. I really think you are in way over your head and will do more harm than good, and increase your maintenance expense long term and shorten your car's AC life short term.

Anyway, posts like this concerning operational issues belong in the Infiniti Online Mechanic Forum, so you may try a search there. But please do some research before attempting shade tree repairs. Another good source for general fixes is http://www.fuzzcats.com/J30/

Do get the FSM and TSB also.

[TetsuoK]

well, i'm really not too worried about doing any damage. Granted, I don't have auto a/c experience, but I did quite abit of work on home a/cs and refrigerators as a technician for a couple years.

I flipped the hood for about 5 minutes and made a quick assesment.

The evaporator core is clean, no holes. The suction accumulator looks fine, all the hoses I can see from the condensor and to the condensor look fine, and the compressor looks to be in good condition - i'd need to take a better look to make sure its actually fine.

I just can't seem to locate that low pressure valve, and don't have a chilton's for the car yet.

Just wanted some advice for where to find it. I figured it would be ont he left side, but my eyes are missing it.

[elwesso]

i moved this to the J30 forum!!!

CHILTONS... EWWWWW

Anyway, the low service port is on the low side accumulator thing you talk about..

[brandonjustice93J30]

who needs a Chiltons when the factory serivce manual is in the trunk on the left hand side? There's a chapter on the HVAC system...and the port is located against the firewall on the passenger side. I just refilled mine after the system had pieces replaced and they wanted nearly $150 at the dealer to refill it. I spent $40 roughly on two cans of refrigerant/oil combo and another can of oil, works great now.

[TetsuoK]

heh. apparantly I do.

It and the jack were removed from that nice little pocket at some point during the car's previous ownership.

If anyone knows the part number for it (which i surely don't) I'd like to order it from Nissan.

[DominickJ30]

See, the problem with that is you probably over of underfilled the system, possibly causing problems in the long run. Thats why its important to put the proper amount (in weight) into the system.

[TetsuoK]

coming from a cfc cert background, I've learned alot about refrigerants.

Something few people know is that you can refrigerate your car with propane in the system if you really wanted to. It has a flashpoint above 1000F, and unless your car catches afire because of a gasoline leak, you have little to worry about in the case of it. its also very environmentally safe.

I don't recommend doing it unless you have extremely durable aluminum (or better) components, and that is topic for a completely different discussion.

When it comes to 134 leaving the system, its seldom ebcause of the leaks you might consider. r134 is a teeeny tiny molecule. Even the thickest of metal is porous, and left in a parking lot on a sun (or in the case of a house, when people mount a/c's on top of the roof as opposed to the shady side of the house) r134 has an amazing knack of finding its way through each little pore of metal that flexes itself in and out as night turns to day and day to night. You don't need a hole in a seal, or a loose clamp in order for refrigerant to find its way out into the air. It will do it on its own if you neglect your a/c.

Now as far as overcharging your system - that is bad.

Undercharging is a little different, and for diagnosing some problems, its really nothign to worry about, and I can tell by the low micron measurement, that there isn't much in there right now.

[brandonjustice93J30]

I read the underhood placard and filled to factory specs using my friend's Dad's AC guages from his shop....low chance of underfilling or overfilling in my case...I didnt quite do the wal-mart special

[brandonjustice93J30]

ouch...I'm sure there's been a few posts in the for sale area with service manuals....and in my opinion better to just get a different jack if you can spare the trunk space

[vishesh]

I've re-filled the refrigerant in my J30 twice in the past two years from the low-pressure valve. I basically end up having to re-fill it at the beginning of the spring/summer season (obviously, there is no need for A/C during the fall/winter).

Anyway, like brandon said, the low-pressure valve is near the firewall on the passenger side. IIRC, it has a blue-ish colored cap that has "L" embossed on it. I just followed the instructions on the re-fill kit and watched the included gauge carefully to make sure I didn't overfill. Piece of cake.

Maxnix, I think you are being a bit pessimistic in discouraging TetsuoK from re-filling. Especially given what has been said about how easy it is for R134a to leak without there being a real problem.

Also, as a final note, there is a self-diagnostic procedure described in the J30 FSM that you can use to diagnose any major problems with the cooling system. I don't remember where it is off the top of my head, but it can be done entirely through the controls on the in-dash A/C control panel. I recommend running this diagnostic first to make sure that it is only the low refrigerant--and not something else--that is causing the problem. If you can't find the diagnostic procedure in the FSM, let me know.

[TetsuoK]

Yeah, like I said, I dont' have the FSM because it wasn't included with my car, so if you could fill me in on that, i'd GREATLy appreciate it.

Also, if you could look on the lower left of the FSM, there should be a part number, i think its 11 digits. if you could let me know, i can probably also order it real quic.

[vishesh]

Here are the relevant pages from the FSM. This should have all the info you need to conduct self-diagnostic procedures on the cooling system using nothing but the in-dash temperature controls.

[vishesh]

Page 33

[vishesh]

Page 34

[vishesh]

Paage 35

[vishesh]

Page 36

[vishesh]

I don't have a physical copy of the service manual...just electronic, so no part number. There are plenty of service manuals on ebay though. Just search for "j30 manual". Careful not to get the owners manual...the service manual has all the detailed info.

[TetsuoK]

thanks alot vishesh, i really appreciate it.

I also managed, in the meantime, to find a digital copy of it at phatg20.net

i also found my friend's civic manual, so we're going to work on his car this next week as well.