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Rob2529

Member Since: 22 Nov 2010
Location: Wirral, uk
Posts: 873

2004 Range Rover 4.4 V8 Vogue Auto Oslo Blue

EAS pressures and compressor stuff

Hi Guys
Quick couple of questions. What pressure does the EAS run at? Also anyone with P38 knowledge. Why did their air compressor kits consist of piston ring and a liner? Mainly I interested in the liner side? I've got an old wabco from our L322's that I stripped a while back and working with another member to come up with a dual pump system. When I stripped the old compressor I don't think their would be a need for liner unless major damage had be caused to it. Any guidance form ex or current P38 owners would be great. 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!

9th Aug 2011 7:36pm

dan_uk_1984

Member Since: 12 Nov 2008
Location: Bude, Cornwall
Posts: 3758

Cant answer your questions, but I too have looked at a dual pump system - came to decide it would be much more fun to make the later (more reliable and heavier duty pumps from 2006+) work in the earlier cars.

Would still give the dual pump a go, its something I always wanted to do from the days of the classic. Let me know if I can help in any way possible!

Dan

9th Aug 2011 8:18pm

Rob2529

Member Since: 22 Nov 2010
Location: Wirral, uk
Posts: 873

Cheers Dan. Any knowledge of the workings of the current system would be great. The new compressors sound good but sound expensive. Adam has picked up a 2nd heavy duty compressor for £25 which if we can get it to work is a cheaper system than £300 for a new pump. What controls are on the current compressor? 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!

9th Aug 2011 9:07pm

dan_uk_1984

Member Since: 12 Nov 2008
Location: Bude, Cornwall
Posts: 3758

I believe the L322 compressor has a temperature sensor on - in ye olden days it was just a thermal cut out switch.

Part of the EAS ECU logic is that it "expects" to see the compressor temperature rise as the compressor runs. If the temperature remains static whilst active then this will cause a fault...

There are a couple of options round this, personally I would run a second compressor in tandem to the original one. I would power the second compressor via a relay fed from the original compressor. This means you would half your compressor run time/load.

Alternatively you could figure out the resistance values from the sensor and fit a similar one to your secondary pump...

Are you indenting on fitting a second reservoir? In theory this would give you greater benefits - currently you only get 50-75% of a hight change from the reservoir, the pump often has to make up the rest. If you could go from access to off road using all air from the reservoir this would be great. Then obviously with two pumps sharing the load of filling the reservoirs you wouldn't be adding any extra load on them...

9th Aug 2011 9:17pm

Rob2529

Member Since: 22 Nov 2010
Location: Wirral, uk
Posts: 873

Sounds like a second tandem system is the way to go. Let the logic do it's stuff on the old compressor and when it's req the second pump can help with the load using a relay system. A second tank sounds good but again expensive and complicated to plumb into the existing system. Plus I have LPG so space is a premium. Do you know anything about volumes from the reservoir or what volume the compressor can deliver don't want to plumb in a second compressor and it be under powered. 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!

9th Aug 2011 9:32pm

dan_uk_1984

Member Since: 12 Nov 2008
Location: Bude, Cornwall
Posts: 3758

The reservoir is bolted to the underside of the car, plenty of room for another. Again, just inline so the pressure switch on the original one does the work...

No idea what the compressor is rated to - anything in the WSM?

9th Aug 2011 9:35pm

SteveMFr
Site Sponsor

Member Since: 22 Nov 2009
Location: Strasbourg, France
Posts: 995

Re: EAS pressures and compressor stuff

Rob2529 wrote:
Hi Guys
Quick couple of questions. What pressure does the EAS run at? Also anyone with P38 knowledge. Why did their air compressor kits consist of piston ring and a liner? Mainly I interested in the liner side? I've got an old wabco from our L322's that I stripped a while back and working with another member to come up with a dual pump system. When I stripped the old compressor I don't think their would be a need for liner unless major damage had be caused to it. Any guidance form ex or current P38 owners would be great.

I'd have to go back to find the exact specs on operating pressures - the system works at up to ~10bar.

-Long Explanation Ahead-

No official compressor refurb kits were ever available - you had to buy a new compressor (€800 here in Germany and France). The compressor is a dry running piston compressor - no oil - and has a teflon piston ring.

P38's (and RRC's) had a very general wear pattern in the EAS: the air lines were 'plugged' into place with a sliding collet (the greater the pressure or pull on the air line, the more the 'fingers' of the collet squeezed the line) and sealed with rubber O-rings. After 5 or so years, the O-rings began to shrink and the lines leaked. The compressor worked overtime trying to keep the system pumped up. At some point, the teflon piston ring wore away and, in a worst case, the piston scraped and scored the cylinder bore. The EAS ECU noticed that the compressor was running for extreme lengths and the system was still low on air (or the compressor overheated) and the ECU decided it was time to shut everything down for safety's sake. This meant that the RR was dropped to the bump stops and 'EAS Fault - Max 35 MPH' was displayed in the cluster. The only way to clear the faults was the dealer Testbook diagnostic tool or later the Autologic or Rovacom systems at independent garages ~€100 (this lead to the development of the free EAS Unlock Suite and, in effect, our present system as well (3rd post down and later posts in the thread)).

The dealer's solution was:
- a new valve block (as the O-rings were not considered dealer replaceable) €800
- a new compressor €800
- fault reset with the Testbook
- labor

All in all somewhere in the vicinity of €2200-€2500.

Crafty P38 owners (me, for instance

) discovered that the O-rings were standard items that could be purchased at any industrial supply specialist for about €1.50 and even craftier P38 owners started making compressor piston rings. These compressor ring makers (I believe amongst the first was the Goswin from http://www.landroverwinkel.nl/ ) then got complaints from people who had installed the teflon rings on compressors with badly scored cylinders and the problem reappeared within a few days. So they started making replacement cylinders as well.

That's a very comprehensive summary P38 compressor probs and of why there are replacement compressor piston rings.

Why do they not exist for the L322? I've never taken a L322 compressor apart - I don't know how difficult or easy it is and what the seal looks like (if you have please post pics!!). But if it is not too difficult to get to I'd surmise the following:
- these developments for the P38 took place from around 2005 on when the series was 10yrs old, the demand had grown enough, and P38 prices dropped to the point where people who didn't have €2500 to spend every time the car was in for service were purchasing them. We're just getting to that point with the L322.
- LR dropped the O-ring/collet arrangement in favor of a much more reliable flange nut/flared tube system
- compressor prices aren't quite as ridiculous for the L322
- the L322 doesn't drop to the bump stops at every EAS hiccup

TBH, I don't really see much point in a 2nd compressor. If the EAS isn't leaking and the compressor seal is OK it should last a good long time.

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

10th Aug 2011 11:43am

dan_uk_1984

Member Since: 12 Nov 2008
Location: Bude, Cornwall
Posts: 3758

Re: EAS pressures and compressor stuff

SteveMFr wrote:

TBH, I don't really see much point in a 2nd compressor. If the EAS isn't leaking and the compressor seal is OK it should last a good long time.

Does there need to be a point?

10th Aug 2011 11:47am

SteveMFr
Site Sponsor

Member Since: 22 Nov 2009
Location: Strasbourg, France
Posts: 995

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

10th Aug 2011 12:10pm

swast4

Member Since: 07 Jan 2011
Location: Wirral
Posts: 69

2002 Range Rover 4.4 V8 Vogue Auto Java Black

Thats a great reply, just the info I was after, it makes perfect sense now why you may need a new liner. The compressor Rob lent me is fine, in regards to the liner and it is still running and delivering air but it must be a reduced rate due to age and wear.

I stripped down the compressor and was shocked how basic it was and how easy to strip down. I have taken loads of photos but am unable to display them yet as I don't have a host set up. The idea of having the second pump running parrallel was simply because I didn't understand fully how basic the system is and believe a new teflon piston ring should do the trick.

I am in work tomorrow and will bring it in to see if any of the engineers can point me in the direction of getting some made. I am in a fortunate position where I can reset my system numerous times so can experiment away, I'll keep you posted.............

Adam

PS The so called Heavy duty pump I bought is tatt and not suitable.

14th Aug 2011 11:35am

Rob2529

Member Since: 22 Nov 2010
Location: Wirral, uk
Posts: 873

That's some good info. Thanks. Nice to know the fix for our compressors should be as simple as a pistonring. Adam will post those pics you sent me when I get home tonight. If the compressor is still stripped can you remeasure the ring fully compressed? 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!

14th Aug 2011 1:17pm

SteveMFr
Site Sponsor

Member Since: 22 Nov 2009
Location: Strasbourg, France
Posts: 995

oh - then ignore my reply in the other thread...
RRC 2Dr, RRC 4Dr,
P38, and LM
(wife thinks I'm nuts - prob right, too)

14th Aug 2011 1:53pm

swast4

Member Since: 07 Jan 2011
Location: Wirral
Posts: 69

Will do Rob. What othe rthread Steve ?

14th Aug 2011 3:10pm

SteveMFr
Site Sponsor

Member Since: 22 Nov 2009
Location: Strasbourg, France
Posts: 995

http://www.fullfatrr.com/forum/topic7045.html
RRC 2Dr, RRC 4Dr,
P38, and LM
(wife thinks I'm nuts - prob right, too)

14th Aug 2011 3:13pm

swast4

Member Since: 07 Jan 2011
Location: Wirral
Posts: 69

Ok got that - No probs.

Right I have uploaded pics to photobucket so Ill see if I can post pics of compressor:-

http://i1226.photobucket.com/albums/ee409/...9ffe0f.jpg

14th Aug 2011 4:00pm

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