Good morning,

’06 SE with 201K. Recently replaced desiccant in drier and upgraded to metal cap. Replaced air line elbows on back of compressor because I got bubbles from those connections. Unplugged battery for a bit (semi-hard reset). No amber light on first start, but 3 out of 4 of the rest of the runs had an amber light. Truck goes up and down just fine. No evidence of valve block or bag leaks.

At this point I’m guessing compressor is weak, voltage output from alternator is causing a fault, or suspension computer was damaged (some water in cabin from previous owner). Would it be wise to get a piston seal kit from the internet or just find a new compressor? This is before I chase the other two gremlins.

Yes, I know I need a diagnostic tool. But I feel like I’m going down the right route…

Thanks again!

 

In UK, X8R makes a ton of different repair kits for the Hitachi compressor. They come with somewhat ok instructions, too. If I remember correctly they had a few videos on how to test the compressor on a bench.

I would seriously recommend against throwing the parts cannon at the problem but instead try to diagnose it properly. Also, you could just as well have a problem with the electrical cabling (continuity), it is not always the compressor which is at fault.

 

X8R is who I used for the drier and cap. Britpart supplied the other hoses. I dug around on the forum and one individual had some good luck with the Autel AP200 which is like $40. I don’t have a ton of funds for a GAP at the moment.

I’m just excited to drive this thing and I hate warning lights. Plus, I don’t wanna burn out the compressor. I’ll get the diagnostic tool and see what I can get out of it.

Thank you for the kind and helpful reply!

 

I know I’m sometimes guilty of saying “get an IID” but, really, it is possible to live without one. It’s just that a generic code reader can leave a lot to be desired. If the Autel that you have can read all the codes and show them you can plenty done already. Google each code and you’ll be on your way.

 

Elbows on back of compressor cause of bubbles? You dont mean the larger lines, right?

 

Those are exactly what I’m talking about. Why?

 

I think DakotaTraveler means the coolant lines to the rear AC?

 

Because those are intake and exhaust and never under any pressure so it would be incredibly weird they would bubble.

 

I saw some air spurting out at the fitting of the bottom of the two. Meaning the bubble solution was getting flung from it. I replaced them and will check for leaks again.

Also good to know. I thought they were under pressure. Makes me feel better in case I messed anything up.

I don’t have rear AC in mine.

The only other place I can think of is the fitting at the valve box/contraption between the compressor and the reservoir. It’s the one coming from the compressor with a hook/staff shaped hose.

My diagnostic tool arrives today, so I can narrow some stuff down finally.

 

Diagnostic tool gave me the “reservoir not filling fast enough” code. I guess I still have a leak somewhere or I need to refurbish the compressor piston and cylinder seals. Or both.

Edit: I got some live data: roughly 212+ psi while compressor runs. Gets to about 78C before turning off. I also noticed rear right height sensor reads low in both height and voltage (1.75V or less). Could that cause the issue, too?

Super edit: I found the leak! It’s on the center valve block. What kind of fittings are the kind with the nut and screw? They are all over the center valve block. It’s the smaller of the two.