I'll try again

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And try again

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Bingo 3rd time lucky, her we go.

This shows piston with out ring fiteed.

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It would def be interesting to get the dimensions on a new ring as a comparison.

Internally it looks very similar to the P38 compressor - except that the ring on the P38 compressor is a cup shaped bit that's much thinner than the split/expanding ring you have. It would be interesting to do a compression test on the compressor as well.

BTW, so the compressor is U-shaped with the motor forming one leg of the U and the cylinder the bottom part. So whats the black bit that's nearly as big as the motor that's the other leg of the U? And the funky valve at the end? 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

The black bit the same length of motor is the air drier, basically a cylinder with silca gel inside, nothing complicated. there is a thicker pipe going back to the suction (spillback). There are 2 funky valves solenoids. One of them is a normally closed and open when motor is running (to stop system draining out and to enable compressor to be changed and I think the other one releases the air out of the system when lowing vehicle.

Adam

Nice one ad. Just saved me a job! [img]http://www.fuelly.com/driver/rob2529/range-rover[img/]
04, 4.4V8, Vogue Oslo Blue with LPG.
"You can sleep in your car, BUT you can't race your house!!!!"

If something can't be fixed with a hammer....... You have yourself an electrical fault!

Thanks Adam. That really demystifies things then. So the funky valves will be inlet/exhaust.

I've not had to work on the mechanical bits in my EAS yet after 3+ years of ownership - in contrast to the P38 where that joy didn't last 3 weeks (honest!). 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

I've just given the compressor to our machine shop in work to see what he can do.

But looking at the dimensions in the photos I've got:-

36.24mm Cylinder Bore
26.46mm Small diamenter of piston
4.76mm Thickness of piston ring

37.45mm Diameter of piston ring with no tension on it.

So if the max diameter the ring can be fully compressed is 36.24mm and the existing diameter of the piston and ring is 35.98mm (26.46 x (2x4.76)) then there is only 0.26mm of wear, which doesn't appear to be alot ? The only other thing of any note is the edge of the ring is very slightly curved, but only very slightly.

The fact that the ring is slightly bigger than the bore should mean that it takes up the slack, but when the compressor and ring get hot ,would it contract and pull the ring into the closed position ?

Any thoughts ?

swast4 wrote:

then there is only 0.26mm of wear, which doesn't appear to be alot ? The only other thing of any note is the edge of the ring is very slightly curved, but only very slightly.

Any thoughts ?

Those were exactly the reasons I said that it would be interesting to have the dimensions of a new ring and to do a compression test.

If the ring is not what's causing the problems with your compressor then it has to be either inlet or outlet side. On the P38 compressors, the reed valves (if they are called that - 1-way inlet/outlet valves) have been know to fail. Air filter clear? Is the 'funky valve' switching properly? 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

Yeh I know what you mean but it means forking out £330 for an experiment. The inlet valve on the compressor looked fine with no damage or contamination. Also the inlet filter is just a round metal gause on the compressor. Not the funky witches hat tap thing.
Since I repaired my leaking d/c line my suspension is a bit faster moving between positions, I will see if I get the resevour filling fault again.

Adam

Hi Adam,
I know. Tis stupid. Sooner or later someone will get ahold of a new compressor and post the dimensions (prolly later tho - as only the fewest of schmucks will take apart a brand new compressor ).

If you have a compression gage in your toolbox, you could -theoretically - do a compression test. I'll try to find time to do something similar...

Sooner or later.

Steve
 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

Hi Steve,
The type of ring we have is apparently a split rider ring design, this is the funny overlaping type arrangement that you see. The piston itself has a small split pin on the side where the piston ring locates, to stop it spinning round the ring causing speedy wear. I have just been reading about 'split rider ring design' and read an interesting section as below:-

Do split rider rings need to be pegged to stop them turning
on the piston ?
It is important that split rider rings are stable on the piston and do
not spin, this however is normally achieved by the correct design
of pressure relief grooving but can also be achieved by pegging
the rider ring. This pegging also allows the rider ring to be turned
on the piston enabling its life to be effffectively doubled.

Interesting I thought, and might be worth taking compressor apart and turning over the ring. I have just bought a tired second hand compressor and might try it out. When I also got the bits to repair my holed d/c air line I picked up a 8mm OD 'T' piece and thought I may install it with a pressure guage and see it's performance along with tapping up Rob to monitor the Receiver pot pressures.

Adam

That's interesting about flipping the ring over. If only we knew what a new one looked like. My old compressor had a radius on the ring. Have you stripped your old/new compressor yet Adam? [img]http://www.fuelly.com/driver/rob2529/range-rover[img/]
04, 4.4V8, Vogue Oslo Blue with LPG.
"You can sleep in your car, BUT you can't race your house!!!!"

If something can't be fixed with a hammer....... You have yourself an electrical fault!

Not got it yet, will experiment when I get it. That one of yours we havn't got a clue which way it was ? Is your cars stearing still good ?

I took it off the first time I stripped it an never noted which way it was. We could test it both ways? Obviously work is busy then! Lol. Steering is amazing! [img]http://www.fuelly.com/driver/rob2529/range-rover[img/]
04, 4.4V8, Vogue Oslo Blue with LPG.
"You can sleep in your car, BUT you can't race your house!!!!"

If something can't be fixed with a hammer....... You have yourself an electrical fault!