Drier recommendations

[Patcon]

I would pressure check with dry nitrogen not air. Air will introduce moisture. The nitrogen will help purge the system. Charge with niteogen. Then after testing, vacuum it down and charge with refrigerant

[S30Driver]

To clarify what I have done, I have or had a working converted to R134a system but had a very slow leak requiring me to recharge the system every year or so.  I have just rebuilt and installed a fresh motor and as part of that, I purchased a new Sanden 508 compressor to replace the factory unit. (the source of my leak)  With the new compressor installed, I have to replace the 2 flex lines that connect to the compressor which has the high / low ports in a different location requiring about 5" longer lines and connections with modern o-ring fittings.  Nissan used most all #8 flange fittings in the factory system.   Currently waiting on delivery of the parts to build and crimp the new flex hoses, then... I can re-charge the system.  If I remember right, I think I used close to 2+ 12oz cans to charge the evacuated system. 

Looking back, the drier was the easiest part of my upgrade, the copper hardlines connected easily, and fits perfectly in the stock bracket.

Edited July 13, 2021 by S30Driver
addition

[Cruzzar]

As mentioned above I would like to keep the engine bay stock looking . I would like to keep the hard lines going to the compressor which would entail using a drier with compression fittings. I will be upgrading to a new condenser that will have o ring fittings. Hooking up the condenser to the drier would require going from an o ring (on the condenser) to a compression fitting on the drier which would be easy if I were to put a hose in the process of connecting the two. If I try to run a hard line between these two then the only way I see that this can be done is to use an o ring to compression adapter. Has anyone ever used one of these adapters? I have never had the need to make a connection like this on the cars that I have worked on and therefor have never used an adapter like this. Adapters are available from Nostalgic AC.  Nostalgic AC - Flare Adapters - Fittings & Hose Kits

[S30Driver]

You need to find out the fitting size on your new condenser.  #10  or  #8.  The flare fitting on the drier is #8.

I am waiting for the adapter from Nostalgic Air to convert from the evap hard line #8 flare to #10 hose for the compressor suction port.

You cannot use hard lines directly to the compressor ports since it is bolted to the motor block and can move.  That is why Nissan used 1 foot flex lines which I need to extend 4 or 5 inches with o-ring fittings and service ports due to the new and different compressor.

Edited July 13, 2021 by S30Driver
correction

[Cruzzar]

I am aware of using a flex line between the compressor and condenser. My question relates to the hard line from the condenser to the drier.

[EuroDat]

On 7/11/2021 at 1:07 PM, Dave WM said:

I think its 75% OF the R12 charge in the same system. Not "more". May want to double check this.

Hi Dave, Just went through my notes and you are correct. I found a formula: R12 charge x 0.9 - 0.12kg = R134a charge. It is an approximate calculation and generally results in 70 to 85% of the original charge.

Ex. 1.2kg R12 x 0.9 = 1.08 - 0.12 = 0.96kg R134a (80%)

Like I said, NO expert here......

[cgsheen1]

The original hard lines use standard flare fittings for refrigeration tubing. (Journeyman Plumber (besides novice HVAC tech) - we used flare connections on soft copper water or air tubing as well...)

HVAC Flare fittings aren't the same as AN fittings - they use a different bevel - you can't mix them.

The liquid line in an early Z is just stock 3/8" soft copper refrigeration tubing - can be bent with a 3/8" tubing bender of you choice, can be cut and re-flared with an HVAC flaring tool, can be brazed. I don't think the stock copper can be made an o-ring connection but I don't know for sure... I do believe there must be a way to transition (if an o-ring fitting can be brazed onto copper tubing, there you go...).

Euro is correct R-12 volume vs. R134a - I go off pressures, not exact refrigerant weight, but the conversion above will get you in the ballpark.

(As a plumber I have a fondness for flare fittings and a subsequent ambivalence for o-ring fittings. (I said "ambivalence" but I really meant "dislike"...) I find the flares to be much more trouble free when done correctly. And since I have all that $^!# from my plumbing career, I can easily make or repair flare connections which, I guess, some people struggle with.)

[Cruzzar]

S30, the condenser that I am using (new from Vintage Air, 12" x 24") has #6 and #8 0 ring fittings. I will try to run a hard line from the #6 condenser fitting to the drier. The drier I have has #6 male flare fittings so the exit side of the drier will mount up to the stock hard lines going to the evaporator. I am going to use one of NostalgicAC's flare to o ring adapters. I will probably have to replace the stock Datsun #6 hard line that goes from the condenser to the drier with a hard line that has o ring fittings on both ends.

[S30Driver]

That all makes good sense.  Replacing many of the #8 flares that Nissan used with o-ring fittings should be more resistant to any future leaks in the system, which is a very good thing.  (although cgsheen1 likes the flares which makes me happy since the only o-ring fittings in my system are on the new compressor)

Should get the last fitting I need to crimp the line to the low suction side of the compressor today.  It is a #8 flare to #10 hose straight beadlock fitting.  Then I should be able to draw down the system and recharge it.

Interestingly, I purchased the o-ring 135 degree compressor fittings with service ports from Cold Hose.  Nostalgic Air did not have them with the option of the service port either left or right side, only one side.  I wanted ease of access to the service ports with the low side clocked left and the high side right.

Edited July 13, 2021 by S30Driver
addition