I have a 1987 IrocZ 305 TPI. I am really having a hard time finding a compressor with a threaded pressure cut off port? I just bought a reman R4 from Autozone that claimed it was a exact fit for my car and yet there is no pressure cut off port! This is the second one I have bought that have claimed exact fit with pressure switch! Im ready to get this project done have the new accumulator new orifice valve and yet Im finding it very hard to find the correct compressor? anyone had this issue or know of a compressor with the pressure port for this car? Much appreciated!

 

I'm pretty sure you have to put your own in there. Maybe there is a block off plug in there now.

I'll tag @Fast355 he knows a lot about the AC systems. Maybe he can chime in.

 

yes thanks. Im going to look it over a little better. The few Ive seen have the threaded port covered with a snap ring. But they sre are hard to find. When I return the latest one. Im going to look at what they have in stock. Wont be buying anything I cant look at.

 

Yeah double checked the Autozone compressor wont work. This is really a pain in the *** finding anything!

 

Stay away from Auto Zone.
Try Rock Auto, and get a GM original.
Just replaced the compressor in my 94 TA.
Had no issues.

 

Thanks, just impossible to find the Harrison R4 heavy.

 

is this it, not sure if 1987 has serpentine belt ? https://www.rockauto.com/en/moreinfo...t=6628&jsn=577

 

Im pretty sure its this one. It has a v belt. Thanks for the info!

 

Just found out. That one wont worke either. I need one with a threaded pressure switch port on the back. Seems all the new and remans dont have this? Not sure what I will do. Keep looking I guess.

 

Why do you need a threaded pressure port? Cant you just get a non threaded pressure sensor and go that way?

 

because there are 2. One near the accumulator and one in the compressor. Without the one in the compressor it would throw the whole system off. Unless Im getting incorrect info? But thats the way Im understanding it.

 

 

I think midias is telling you to just get the sensor that fits the new compressor.

 

mine is the original Harrison compressor that has a electrical connector that plugs into the compressors cut off switch. The new compressor I bought has no place to connect that part. All I see is a small area covered by a snap ring. Not sure whats behind that snap ring? But it doesnt seem to be for a pressure cut off switch? And of course no documentation came with the new compressor. I would be very happy if this would work!

 

Does it have this?

 

Yes. So that is where the switch goes?

 

I think so.

I was really hoping @Fast355 would stop by and chime in. He's replied in several of your other threads. He knows a lot about AC systems and loves to talk about working on them but mostly in his Vans he loves so much. Maybe he didn't get a notification when I tagged him earlier in this thread.

 

Thanks everyone! I seem to have gotten some incorrect info before I came back to the forum for answers. Thanks again! Awesome!!!

 

Yes that’s the correct place for the high pressure switch on the R4 compressor.
To be honest I’ve never see a screw in pressure sensor on an R4, not saying it doesn’t exist I’ve just never seen one, all the thirdgens I’ve ever worked on has the one I posted in the picture.

 

Yeah someone gave me some incorrect info. Thanks for helping out much appreciated! My Harrison lasted almost 40 years. They dont make em like that anymore!

 

Glad you guys chimed in before I saw the notice I was going to post this. But you had it covered

 

I have been busy working on a lot of other stuff. I missed the notifications. I have also never seen a R4 with a threaded pressure switch, just the units held in with the snap ring. Just so that it will show up later in the event someone needs the information, the 1 pin sensor that used a knock sensor connector are no longer made. The replacement is a 2 wire sensor. Same sensor setup, just need the 2 wire pigtail. 1 wire on that pigtail gets grounded externally and the 2nd wire splices in place of the factory connector.

 

Everything went pretty easy. Got the new compressor in replaced the accumulator, compressor orrifice with a R 134A orrifice. Replaced all O rings flushed the whole system and added the proper amount of PAG oil.. Then was ready to do a final vacuum and I got it to zero not 35. It turns out the low side port on the back of the compressor is leaking. The compressor came with 2 O rings or some call them gaskets. One Red one black. The red is thicker than the black I believe thats for the high side but it sure does not look right. I did forget to use pag oil on them. would that cause a leak though? Ive never used these kind of O rings and thought about getting the HBNR rubber O rings but dont really want to do that if I dont have to The good thing is its pretty simple one bolt and super easy to get at.. anyone else run into this issue? Thanks alot all!

 

I have never had a problem with the aftermarket variety box green o-ring kit rings, and I definitely lube each one. Your kitted metal clad lineset gaskets may be the wrong ones.

 

thats what I thought. Gonna give them one more try then check out the normal green o rings. Thank you!

 

Heres the problem