I have been reading all the posts about flushing. I am following the procedure that I think Jazzman posted. In preparation I removed the orifice and sealed the line back. I took off the accumulator and also disconnected the other end from the compressor.

Yesterday, I pumped in some flush in to the pipe that flows through the orifice . This one:


I pumped in the whole 14oz can. and nothing came out the other end. I let is sit for 15 minutes like the instructions indicated. I went to blow it out with compressed air and there seems to be some back pressure. I can't actually view the compressor end while I am doing this, but I do see some spray of the flush in the collection pan I put under the compressor end.

My concern is the back pressure. I thought it would just push the flush out and it would flow freely, but even after 10 or 15 seconds of compressing the pipe it still has back pressure. I tried running compressed air through the other pipe and there was no back pressure.

Am I doing something wrong?

I will be back at it again this morning.

PS- Can someone comment on whether this accumulator appears to be the correct one for a 88GT?

the orifice tube is still in the circuit.
that's what is causing the back pressure.


you need to remove the orifice tube from the area with the blue arrow.
and blow everything out again

[This message has been edited by buddycraigg (edited 07-12-2008).]

Why Buddy you sure are up early. I was not aware you were an insomniac, too.

I already pulled the orifice valave out of there, so the back pressure is not from that. I may be just just a worry wart about this. It's my first time messing with AC and I don't want to screw up. How long should it take for me to blow out 14oz of flush with compressed air?

That's the evaporator, I thought I read somewhere that it cannot be flushed in-car? Also, isn't the Fiero condenser a parrallel flow type, which cannot be flushed, or is it just difficult to flush?

The accumulator shown in the picture looks like the correct one for 85-88 Fieros, since the pipes are 120 degrees from each other, and it has the port for the pressure switch, and the low side port. 87 and 88 Fieros with the duke had a V5 compressor that didn't have a pressure switch on the accumulator.

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1984 Fiero SE

I don't know. I just read a few posts saying that if you pull the orific out and close back up you could take off the accumulator and flush from those big pipes all the way to the back. Not true?

I hope you disconnected your compressor when you did that. You do not want AC flush to go through the compressor. It can ruin the seals in the compressor. Usually you are supposed to run AC flush through the system starting and ending at the hose that connects to the compressor.

If I understand you correctly, you disconnected the hoses at the compressor and are trying to backflush the entire system in one step ... all the way from the evaporator, through the orifice tube housing and condenser, and back to the compressor fitting. If so, that means you are also trying to flush through the muffler on the hose assembly, which is a no-no. At the very least, you will now need to replace the hose assembly.

The proper way to flush the system is to flush each short section individually ... evaporator separately, condenser separately, and each tube section separately. Yes, it's more work, but it avoids just flushing debris out of one place and into another. Except for the compressor hose assembly, it's probably still not too late to do that.

[This message has been edited by Marvin McInnis (edited 07-12-2008).]

quote Originally posted by Marvin McInnis: If I understand you correctly, you disconnected the hoses at the compressor and are trying to backflush the entire system in one step ... all the way from the evaporator, through the orifice tube housing and condenser, and back to the compressor fitting. If so, that means you are also trying to flush through the muffler on the hose assembly, which is a no-no. At the very least, you will now need to replace the hose assembly. The proper way to flush the system is to flush each short section individually ... evaporator separately, condenser separately, and each tube section separately. Yes, it's more work, but it avoids just flushing debris out of one place and into another. Except for the compressor hose assembly, it's probably still not too late to do that.

Yes, The hoses were disconnected to from the compressor and the orifice was removed when i did that. Can you tell me which hose assembly you are talk wbout replacing and why it needs to be replaced? Is there a way to verify if it does or does not need to be replaced?

quote Originally posted by sjmaye: Can you tell me which hose assembly you are talk wbout replacing and why it needs to be replaced?

The hoses that you disconnected from the compressor. There should be a small steel "can" in one of the hoses at the compressor end; that is the muffler in the high-side line. You have flushed an unknown amount of debris into it.

quote Is there a way to verify if it does or does not need to be replaced?

No. Since it's sealed there's no way to tell what's in there.

[This message has been edited by Marvin McInnis (edited 07-12-2008).]

I flush the condenser, evaporator and tubes individually and replace the compressor hoses with the muffler, OT and accumulator. Don't even try to flush them nor the compressor (although you can drain the compressor, fill it with new oil, rotate it a bunch and drain that back out.) I flush everything backwards from the direction of flow and capture the flush and inspect it. It can tell you a lot. I take them out of the car but you can do it in the car if you are diligent.

The short section of line with the OT can be flushed but again, install a new OT. Short end goes towards the evap.

The evaporator is a challenge to flush since it's a parallel flow design but it's generally protected from debris by the OT screen. The condenser is the first item to catch the debris from an exploded compressor but since it's a serial flow design you will have more success flushing it. Again, capture the flush and see what comes out of. When you blow air through the evap, it won't hold any pressure. If you are shooting air through it and it appears to hold pressure it's clogged. Consider this too, if you are going to this much effort, consider removing the evap and cleaning all of the leaves and dirt from it. You can really ensure it's flushed, and have a nice and clean evap on the outside for all of the cooler air you will be making!

I follow each flush with 30 minutes of 90 PSI air. I start with 5 minutes of using my finger over the outlet of whatever I am flushing to build pressure and then release it to allow the built up pressure to force the flush out (and any debris). Yep, five minutes of cover and then release. Then I blow 90 PSI air through continuously for 25 minutes with paper towels on the outlet so I can see what else comes out. If you have access to compressed nitrogen that is even better since it lacks the moisture of compressed air. With compressed air you need to vac the system longer to get the moisture out. It doesn't come out as easy as you would think.

When I vac, I pump it down for 4 hours and then let it sit for 2 and then repeat that a couple of times. Yeah, it takes awhile. You will get more moisture out though. I then let the system sit for 4 hours with the final vacuum, confirm it doesn't leak and start the charge procedure.

About the OT: I suggest you use only the stock white OT. Don't be tempted to put a yellow or Ford Blue in there. If the AC warms up at a stop, consider a pusher fan on the front of the condenser.

There are no short cuts with AC repair. Ask me how I know!

Did the compressor die or did you just get a leak?

Finally, go to this forum and ask lots of questions. http://www.autoacforum.com/categories.cfm?catid=2

[This message has been edited by TK (edited 07-12-2008).]