AC - Sourcing parts, some explanations, put in your input!
 

Hey guys -

Trying to put together a pile of AC information. I have my FD and my project car with problem AC systems that I'm trying to fix. BIG problem is many parts ARE NOT AVAILABLE FROM MAZDA. This is a killer problem, which I'm hoping to find a fix for.

So, first, some AC 101. There are only a few pieces to the system -

Compressor. This is the belt driven part on the motor. Compresses the freon (duh).

Condensor. This is the "AC Radiator" at the front of the car. It's like an intercooler for the AC - the compressor compresses the freon, the condensor takes heat out to cool the charge and transfer heat to the air.

Receiver/Drier. Also called an accumulator. This is the metal can up front by the battery. It is filled with dessicant and removes water/moisture from the system.

Evaporator. This is the box under the dash. Has a core (like a heater core) that air flows through. The core is chilled by freon, air goes through, air gets cold.

Expansion valve. This is the "magic" of the system. It's inside the evaporator, it's an orifice. The high pressure freon passes through and blows out to the low pressure side, which results in drastic cooling. This is how the freon gets "cold" and chills the evaporator.

AC lines. There's 2 types, larger low-pressure lines and small high-pressure lines.

O-rings. There's O-rings at most junctions in the system to seal it. AC's run VERY high pressure, and O-rings are the best bet to seal it up.

That said, there are 2 different AC systems on the FD - the Nippondenso and MANA. In general, base/R model cars have MANA, Tourings have Nippondenso. The parts are TOTALLY different - you can't use one part on another system, period. The lines don't attach to each other, nothing.

Also, there are 2 different Freon types. The 93-94 cars used the old R-12 freon, which is now not made any more, hurts the environment. The '95 cars used R-134a, which is used in all modern vehicles and is environmentally friendly.

OK, that said, here's the problems I'm running up against. I can NOT find a MANA R-12 expansion valve or receiver/dryer. Mazda doesn't make it any more - part is no longer available, no stock, you're outta luck. Same goes for the drier. Also, the parts don't seem to be available in the aftermarket.

The drier I have a hunch could be found for a different car. The bracket is attached to the MANA drier, and I bet there might be one out there that would work that just doesn't have the bracket. That's no biggie, as a bracket could EASILY be fabbed. Expansion valve is a whole 'nuther problem - it's pretty specific. The Nippondenso expansion valve IS available easily - I found one at Pep Boys IN STOCK.

Anyhow, I wanted this post to be more concise, but I'm rambling :). Any input on where to get parts?

Dale

Freeze 12 Thread
 

Dale - welcome back from the Dead - is your website up?

Check the Freeze 12 thread - there is a link to a source for a receiver/dryer - not sure if it is MANA or Denso.

Jim

You don't have to use an R-12 specific drier. A drier that will work with R-134a will work with R-12 as well. Same goes for the expansion valve, but the operation will be less than optimal.

The expansion valve can probably be sourced from an auto A/C supply house such as www.ackits.com since it is a pretty standard design (two threaded connectors and a sensing bulb).

Link for FD AC Parts
 

Here's the parts link from the FD thread - I have no experience with these guys, but I may be in the market for a new compressor...


http://www.caawparts.com/index.asp?P...APAAID=1192485

Good - we're getting somewhere! :)

I pulled the evaporator box out of the project car tonight and got the expansion valve out. It's a little different than many of the style - has the threaded in/out for the high/low pressure sides, a sensing bulb, and another tube that goes to a freon source - that tube is very small diameter.

Looking at parts diagrams, it seems a late '80s-early 90's 626 expansion valve is the same. I'm hitting up Pep Boys tomorrow to see if they have one in stock to compare with - I'm also going to look at driers as well to see what they have. I know one of the guys in parts there and he's willing to dig around some.

The drier is looking like it might be a special case. Why they couldn't just use a standard drier I'll never know. That link is a big help, and it looks like that could be a good source for driers. The pics do definitely show the MANA and Nippondenso driers - the weird part is the ND drier is the cheap $10 - most times it's the pricey one! I have a feeling it won't work on a MANA system, though.

I'll keep you guys posted. There's another FD guy in town (Surfmon/Travis) that needs some AC fixin', and I want to get to where I can DO this.

Dale

Good writeup Dale


Later

since the lines that go into the compressor aren't threaded, can you use any compressor?

-Dan

Probably not....the mounts and the pulley alignment still have to match up with what's on the car, even if the lines fit.

I'm not too worried about compressor availability....you can buy parts to rebuild them all day long. I believe it is a Nippondenso TV12.

This might be the correct expansion valve for the MANA system....not sure on the fitting sizes, but it is rated at 1.5 tons (which is about what the shop manual says the system capacity is), and is externally equalized (the little tube you're talking about).

http://www.ackits.com/merchant.mvc?S...Mazda90RX7_1-3

The link that was posted earlier....I don't know if their dryer pictures are wrong, or what, but one of those could be the right dryer, but the dryer with two tubes coming out the top is DEFINTELY wrong. Both the MANA and ND driers used the same sort of pad mount attachment for the lines.

Dryer Pics
 

I agree - the dryer with the "screw-on" fittings will not work - I know my Denso Dryer is a pad type - but I thought MANA was different on the top somehow - and that was a big clue as to which system you have.

Now Dale - I have a new question. Where do you get the "Mineral Oil" that's needed for an R12 (or HC12) based system? The Auto parts places only have the PAG oil that works with R134A.

How about Walgreens? Don't they sell "Mineral Oil" as a remedy for "system backup" - if you know what I mean...

Jim

The most obvious difference is in the sightglass. The lines for the ND drier have the sightglass sitting right on top of the drier, where the MANA system has the sightglass in a little cube about an inch or two down the line from the drier.

I also believe that the ND drier is perfectly flat on top, whereas the MANA drier has a raised area on top where the lines bolt to it.

To get R12 oil, you'll probably have to order it. Or, hit up the more hard core auto parts stores - I got a 1qt. thing of it a few years back at a NAPA, one of the parts places that primarily services mechanics.

If that fails, AC Source has it -

http://www.acsource.com/index.asp?Pa...OD&ProdID=1378

Also, AC source has a REALLY nice high side adapter -

http://www.acsource.com/index.asp?Pa...OD&ProdID=1261

I have that one, lets you put a regular manifold gauge set on the FD's high side.

OK, I went a'searchin' for an expansion valve today. I pulled the evaporator box out of the project car last night and got the valve out of there. Pep Boys, no dice, but NAPA has one that looks JUST like it, it's a general Mazda valve, should have it on Tuesday. They pulled up the pic on the screen.

Weird thing is if you look for "mazda expansion valve" on Ebay you find quite a few Mazda expansion valves that look right, from late 80's/early 90's Mazda cars, like the 323 and 626. Seems like it would be easier to source locally.

Oh, another goodie for you guys - the O-rings for all the pipe fittings in the system used to be CRAZY expensive. Mazda now sells packs of O-rings that are VERY cheap, work with R12 and R134a, and are readily available. I think one of the 10-packs is $3 or so. Attached is a pic I got SOMEWHERE, it's gold - shows what kits you need for the various O-ring sizes.

Dale

I found MANA expansion valves for $8....

http://www.ackits.com/merchant.mvc?S...Mazda94RX7_1-3

I've asked them about the drier, since the one they have pictured is obviously wrong.

Just looked at the 1993 page....they have what appear to be Nippondenso driers for $7

http://www.ackits.com/merchant.mvc?S...Mazda93RX7_1-3

I've asked them to clarify if it is ND or MANA.

Another common failure item is the AC thermoswitch. Again, there are two types depending on the AC type. You can see pictures on pages 3-H 5 and 3-I 5 of the 1993 parts manual in the stickies. Part numbers are FD01-61-J20 for the MANA and ND01-61-J20 for the Nippondenso.

Both are a pain to replace because the probe is integrated into the sensor and is embedded in the evaporator so the R-12 or R-134a must be evacuated and the evaporator removed to replace the sensor. Removing the evaporator is not that hard itself but draining and refilling the system requires specialized equipment or a trip to an AC shop.

for real Dale, hurry up and get your learn on so I can drive around with my windows up

seriously though, let me know if you need an extra hand/brain. I got every afternoon off

t

Hey guys check www.blackdragonauto.com
They carry alot of Z & Rx7 parts to retore many Rx7 as matter fact I have use them to restore two first that I have many years ago. Btw the a.c related parts are located on page 56.
khris

SWEET - just ordered one! Got one in today from Napa, but it doesn't look like it will work. That one looks dead-on, though.

Dale

Here's the thread I started on their forum....they haven't responded since I posted several times last night:

http://www.autoacforum.com/messagevi...threadid=19323

5 & 6 Groove Compressors?
 

Searching Autozone, Advance, O'Reilly's websites, I see listings for 5 and 6 groove compressors (with clutch). I thought all cars used the same pulley and belt - both Mana and Denso. And both systems used identical compressors - true?

The really strange part is that even the "bare" compressors without a clutch are listed as different part numbers - and described as 5 & 6 groove. How can it make a difference if you're just buying a bare compressor without a clutch?

Also - I found this link on the Advance site - the price looks like a mistake - too low by about $100. Someone should try to get a good deal here....

Jim

http://www.partsamerica.com/productd...pe=389&PTSet=A

Hey Dale can you use different condensor? Btw I happen to charge mine about two weeks ago it work fine and then the compressor seems to catch now then, and then it totally stop. I have use the book to troubleshoot per the manual, and it seem if I jump the compressor it work, all wiring is good and I even replace the switch below the dryer, and the dryer itself got replace, except for the compressor and condensor? What do guys think can cause the compressor not to kick in when I turn on the air beside the wiring which I test and I got continued from the compressor to relay to ecu which indicate that wiring is good.
khris

Have you jumped the thermoswitch attached to the evaporator to see if that also helps?

You're sure it isn't shutting down because pressures are too high/low?

Is the relay bad?

Are the fans running constantly if the A/C button on the dash is on?

I am about the replace the thermoswitch on my car and have all the necessary equipment (I think) - recovery unit, recovery tank, gauges, R-12 cans, and mineral oil.

However, looking at the recharging procedure in the manual (section G) I cannot find anything about recharging the compressor oil. Presumably taking the system into a vacuum will remove all the old oil? Is there a service port on the compressor?

Hey I believe you are right about the pressure in the system, after checking everything, compressor work fine if jump, pressure switch was replace same thing, and thermoswtich seems to work fine. However according to the manual if the pressure in the system inaccurate, the pressure switch will shut the cut power to the compressor which make sense. What I don't get is when I de pressure the system I still can't charge it?
Khris