Red powdery AC dust

[Guest intrigueing]

My 95 legacy ej22 A/C compressor spews red dust. Not a ton of it but I wipe it off and it is back in a day. The A/C works great. Anyone have an idea what this is? Is the A/C clutch going out?

[Guest kevinsUBARU]

that is AC clutch dust.

 

I had the same problem, which started out as you describe. Eventually, every time I turned the AC on, there would be a awful screeching/screaming sound. I had by drive/accessory belts tightened about 4 weeks ago, and the sound hasnt come back (And dust is very minimal)

 

Kevin

[Guest meep424]

I thought the magnetic clutch was metal-on-metal? If tightening the belts made less dust and less noise, I'd think the dust was worn, chewed rubber belt dust.

 

The compressor eats up a lot of torque. Methinks tightening or replacing belts would be the best first step. and btw-- the dealer belts I've encountered are much better in quality than the Pep-Boys house brand.

 

meep

[Guest Legacy777]

the clutch is a magnetic type......there won't......ney.....shouldn't be any dust.

[Guest intrigueing]

The belts were just replaced, and it still is doing it. I guess as long as things keep working I can't complain.

[Guest kevinsUBARU]

no idea then....my belts are black as night, and the dust was red as a sunrise.

[Guest Dwaph]

Yup, I have the same thing on my '98 Forester. No idea what it is but I don't think it's from the belt.

[Guest pmonro]

I do not like the belt theory. Belt dist is usually black

I guess it is rust (Fe2o3). As the clutch picks up it rubs minute particles of steel that within a few days show typical red rust.

If my compressor did this I could check my theroy by wiping the red dust with rust killer (phosphoric acid). This turns rust to iron phosphate which is black. However on the grey aluminium of the compressor it would appear to disappear.

However my car does not have this rust which makes me suspect there is something wrong with your clutch or compressor

[Guest WAWalker]

Have seen this on many Subarus. I belive it is rust. Haven't seen or heard of problems with compressor clutches, so I don't think it is anything to worry about.

 

Wayd

[Guest St Nickolas]

Seems to me that it was originally part of the a/c compressor clutch.

 

For some time, I've had an intermittent problem with the compressor clicking on and off quickly (1-2 times/second). I could tell it was doing this while driving, but none of my passengers noticed (i.e., some drivers may not notice). If I had the hood up and was looking, it was obvious.

 

Someone reported a cold solder joint in their heat control buttons that caused theirs. I narrowed mine down to the relay connected to the (hi/low) pressure switches. It hasn't done this lately, so I've not looked further into the problem.

 

Nick

[Guest orphan]

You probably only notice the dust on newer Soobs with factory 134a refrigerant in the a/c. I believe you are seeing residue from the red leak detector in the initial factory refrigerant charge. A little oil and refrigerant mixture comes out around the shaft seal as a normal occurence as the seal ages and the leak detection dye in the refrigerant dries as a reddish powder and gets blown around by the clutch pulley.

[Guest St Nickolas]

FWIW, Mine is a 91 Legacy with R-12 in the system.

 

Nick

[Guest JaapH]

My car is a 96 2,5 with 100k miles and shows the powder too.

[Guest natebg]

Both my '98 Outback Sport (R134a) and my '93 Legacy (R12) experience this problem...

I have no idea what the red dust is...

[Guest JaapH]

that the powder is a mixture of metal scrapings and dried oil...(?)

 

It means that the pump needs a little servicecing (not a overhaul). There is oil in the pump and when that gets old the dust appears. This oil just need to be changed.

He said it was a simple and cheap job but it needs to be done by a specilized company (his neigbour).

 

He also said there is no real rush to take action, but do not ignore it over a long period.

 

Does this make sence to any of you?

[Guest Commuter]

... nothing to worry about. The A/C clutch is metal, and this is just a little metallic dust. Not sure why the red color though.

 

97 Outback with 134a refrigerant.

 

Commuter

[Guest TinyClark]

I'm sure the red dust is the small amount of metal from the clutch that is oxidized. I have a bit on my '96. Worry about it when the A/C fails, probably eons from now.

[Guest Legacy777]

I'm movin this to the archives tomorrow unless anyone has any objections.