Hello! I'm obviously new and appreciate any help you can provide. I have a 1986 Accord LXi 2.0 with Auto Trans and A/C. Don't laugh - for an older Accord, it's very nice and runs like a top! :) I'm replacing the A/C compressor due to failure and have a question about a part that bolts on to the side. First of all, it's a Nippendenso compressor. There is an aluminum block that bolts onto the side of the compressor. The compressor-facing side has four openings which are sealed by equal size o-rings. The out-facing side is where the A/C lines bolt on. When I had it off, it appeared to simply have passages inside (presumably to monitor flow?). When I took it off, I did not notice any moving parts or check *****.

The reason for my question: I'm wondering if something fell out of this block when I took it off and I simply didn't notice? I've put two compressors on the car (both reman). Both times, after reinstalling and re-charging, the compressor engages but builds no pressures (it holds vacuum perfectly and accepted the charge of R134 fine - it's been converted). I've flushed the system, replaced the receiver dryer and the expansion valve as well as the condenser. For the most part, the system is new! Note that it was working fine before the old compressor seized.

This part does not show on Honda's parts microfiche and the car is old enough that no one at the dealerships that I've talked to seems to know anything about it.

Does anyone out there have any idea what this part is, what it does, and its innards? I've eliminated all other possibilities as to why the system builds no pressure - other than this part - which no one seems to know anything about.

I've attached a picture. Any help would be appreciated!

Seattle_Bryan

 

The short answer is I am not sure about your 86 compressor setup.

How much R134a are you putting into the system? Do you have a manifold to test the high and low pressures when the compressor engages?

Look at an online OEM parts site like hondapartsnow for a parts diagram for your accord. You can also download an 86 shop manual from the shop manuals link I put in the common DIY threads sticky on top of the gen tech help forum.

I think there is a sight glass on the receiver/drier, so I don't think there are any check valves.

 

Hello and thanks. Yes, I'm hooking the system up to gauges - no pressures. I've tried amounts of R134 from 1.0 to 1.6 pounds. The system calls for 1.5 pounds of R12 and I know the R134 amount should be slightly less but I've tried varying amounts just to be sure.

I have a factory manual. It doesn't mention this part. The Honda parts microfiche's also don't show this part. And you are correct, there is a sight glass in the receiver drier.

This part is the only mystery in the repair. I'm trying to eliminate the possibility that I missed something when I removed it originally. I find it hard to believe that I've received two bad compressors so, again, I'm trying to eliminate any unknown potential problems.

Thanks so much!

 

Any chance your high and low side valves on ac manifold set are both open? This would prevent compressor from compressing.

Suggest turning the compressor clutch plate (inner part of compressor clutch) by hand. It should turn easily w/ a bit of resistance as each piston compresses gas.

Did you transfer this manifold piece from old compressor to new?
I found an old parts catalog which shows the 10P13E (I think that's what you have) as having a flat upper surface where 4 bolts hold something (your manifold?). Does this manifold divide and cover both high and low pressure ports? Was a new gasket installed under the manifold? I don't see the HP hose connection in the picture.

I think it's unlikely for any check valves to be in this part.

Another resource to consult is autoacforum.com. They have several very knowledgeable auto ac experts.

good luck

 

Hello. The gauges are connected correctly, I'm sure. I'll try turning the compressor by hand but I suspect it will feel as you described. Yes, the piece came from the old compressor (the new compressors have not included this part) and yes, there's a flat upper surface on the compressor this part bolts to. There are four o-rings, not a gasket, that seal it to the compressor. The o-rings are new.

Thanks very much for your input!

 

What was the nature of the failure of previous compressor?

You said the compressor builds no pressure. The high and low sides are staying exactly equal pressure?

This might be caused by a completely wide open expansion valve, although I would have expected to see some difference in high vs. low pressures (wide open is still a fairly small opening in expansion valve).

I assume the expansion valve in this era Accord is inside the evaporator housing inside the car. Has expansion valve been replaced possibly?

good luck

 

It's been a couple of weeks since I last had the gauges connected so I don't remember what the readings were. They were the same however, that's what I recall. I'm getting ready to work on it again tomorrow.

The expansion valve is new and yes, it's in the evaporator housing inside the car.

 

You can also verify the compressor is pumping by looking at the sight glass. You should see some evidence of moving fluid, maybe some bubbles, but not many w/ wide open expansion valve.

If you're moving gas/fluid, then expansion valve must not be restricting flow, allowing gas expansion/cooling.

good luck

 

Is that block a "single" or "double" block.....the 89 just came home and I went to look, the ac hose assy goes straight to the compressor. It's hard to tell in your pic but it looks like there is another "plate" between the hose and the compressor.

Unless you have two bad compressors (?) then I'm with TX on the expansion valve....

Does it need to be different if you are converting....I don't thing so but I can't remember.

EDIT: Added a pic, again this is off the 89 LX.