Aircon Oriface Tube

[76Vett]

Hi all. Can someone tell me the location of the Orifice Tube in a '76 aircon system?
Thank's in advance.

[Vettech]

I have a 78, and I believe the A/C units would be sim or the same. Th orifice tube is located in the liquid line between the Condenser (radiator at front) and Evaporator (AC dash unit). Now if LHD, the Ac is on the RH side, there is a tube coming out of the lower part of the AC box it will have a hex nut arrangement which allows both disconnection of the line and access to the Orifice Tube, somewhere very close to this will be a a very fine capilary tube taped around the metal pipe - this is for the thermostat. Using TWO (2) spanners the hex nut can be opened to get at the Orifice Tube. I think if its blue you replace with blue, etc etc. Most AC places should carry them or direct from the states. If your car is RHD it depends on what they did with the Ac/heater box it could be on RH or LH sides, could be upside down. But remember the Accumulator  or the bright silver alloy canister is allways on the outlet of the Ac/heater box, whilst the Orifice is on the Liquid inlet side. Now orifice tubes have no moving or working parts, so I wonder why you would require to replace this ??????. I suppose it could be damaged if outer metal line has been damaged, or if there has been rubbish in the lines - then the tube could have a become blocked or plugged.

[sirfixalot]

Pretty sure 76 doesn't have one on a 78 it goes in the pipe ex the drier under theguard

[Vettech]

Then it must have a reciever/drier and an expansion valve. 78 definitely has an accumulator (flooded system) and yes from memory it is kinda tucked up the guard. If your silver canister has one tube up the bum, and one tube in the side near the top and a schrader valve very close to it (charge port) it is definitely an accumulater. If the canister has both tubes in and out on the top with a little sight glass then it is a rec/drier type, if so, it will have an expansion vavle. Having said that, there are an infinite number of shapes and sizes of these canisters, but I believe the 78 accumulator system is exactly like the early SLE Comodores, the base models had rec/drier type system. In fact I would say the blower & evap assembly would be identical but on the LH side of the SLE comodore firewall. Umm food for thought.

[76Vett]

Thanks Vettech and Sirfixalot for the advice and you were both correct. The '76 does not have an orifice tube and does have a receiver/drier and an expansion valve. I managed to get a maintenance kit for the receiver/drier, so all is good now. Got a new A6 style compressor to replace the missing one and now system is good to go. On Tuesday it goes to get leak tested and gassed, I hope, so now should have a cool vet.

[Orange72]

Who’s the go to for C3 (1972) air conditioning repairs?
I had the compressor (original type) replaced and repaired an a/c hose that had burnt through thanks to its proximity to the right side exhaust manifold.
The compressor blew 6 months later and the sparky wouldn’t have anything to do with it when I asked WTF!
I’m concerned that there may be debris in the system that may have caused a blockage and or the new compressor to fail. HELP

[Vettech]

Sorry Orange I cant realy recommend anyone esp down Illawara way, I tinker my own.

However : It's normal practice to flush and clean system esp  where the Comp or hoses have failed.

Being pedantic, if I was you, I would have changed ALL hoses, the Acc or Rec/drier, Orifice Tube if fitted and then a complete flush out.
After that suck down to -30"hg,, this vacumm should hold, and will also boil off any moisture still in the system.

Regas with your selected gas, then chill out.

Keep us all informed how you go. Oh and see below a pic of a brand new "White" ACDelco Orifice Tube suit 77 -96 Corvette.

They come in different colours -  always replace like for like.
Is in the pipe close to the evap, allowes a continous fine spray of liquid refrigerant into the evap.

[sirfixalot]

For a replacement compressor I fitted a sanden 508 type compressor to the original A6 type bracket was an easy job took about 4 hours to fit up had to elongate the bracket holes about 2 mm & fitted some 5/16 aluminium tube to compressor lugs to resize down from 3/8 to 5/16. Fiddled around with alignment on belt and found thin child restraint anchor spacers are the perfect distance for alignment. on the back end used a piece of booker rod thru original bracket & a couple of flat straps up to rear leg of compressor.