P38A EAS woes again but different! Solved

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Mukiwa

Well-Known Member
Posts
472
Location
Winsford, Cheshire, near Oulton Park
Hi all,
The EAS has been working now for 3 months. Gremlins have now struck.

Does anyone know what could cause the EAS to pressurise to 120 then depressurise to 20ish, then pressurise to 110, then depressurise, then to 80 psi then depressurise. Then it won't pressurise again? I suspect the pressure switch but I've tested this with 2 different EAS blocks and 2 driver packs. They have brand new NRV's fitted and new orings with no leaks from the pipes and the compressor is refurbed and pushing out good air.

If I use the Nano I can force the comp to stay on - but I don't want to burn it out.
Once the pressure gauge (I have a tee'd in psi gauge on the tank airline) needle starts jumping around it flicks up and down 8 - 10 psi and I can hear the solenoids clicking, the comp comes on for a few seconds, then off, then on, then off. If I go into EAS on Nano then it starts back up as per normal but will only pump until 60 psi.

This started after I had a real fight trying to get the fuel filter off and was leaning over the EAS plastic housing to get a good grip on the filter while I was in France last week. It manifested itself as the rear would go up and then the front wouldn't move. I checked the pressure gauge and it would only go to 60 psi then no more went into the tank. If I manually fill the tank with air it will level the car properly, but I'm trying to fix it.

Just done another check using Wammer's EAS sheet, with the silencer off, all doors closed and EAS running, once it hits 60psi PSSSSSSSSSSSSSS all the air comes out of the block and I can't keep my finger on the hole. These NRV's are not sticking, they have new o-rings, both fitted today.
Anyone any ideas please?
Thanks
Hoppy

PS I have tried searching but it keeps telling me "the search could not be completed please try later".
 
Mukiwa said:
Hi all,
The EAS has been working now for 3 months. Gremlins have now struck.

Does anyone know what could cause the EAS to pressurise to 120 then depressurise to 20ish, then pressurise to 110, then depressurise, then to 80 psi then depressurise. Then it won't pressurise again? I suspect the pressure switch but I've tested this with 2 different EAS blocks and 2 driver packs. They have brand new NRV's fitted and new orings with no leaks from the pipes and the compressor is refurbed and pushing out good air.

If I use the Nano I can force the comp to stay on - but I don't want to burn it out.
Once the pressure gauge (I have a tee'd in psi gauge on the tank airline) needle starts jumping around it flicks up and down 8 - 10 psi and I can hear the solenoids clicking, the comp comes on for a few seconds, then off, then on, then off. If I go into EAS on Nano then it starts back up as per normal but will only pump until 60 psi.

This started after I had a real fight trying to get the fuel filter off and was leaning over the EAS plastic housing to get a good grip on the filter while I was in France last week. It manifested itself as the rear would go up and then the front wouldn't move. I checked the pressure gauge and it would only go to 60 psi then no more went into the tank. If I manually fill the tank with air it will level the car properly, but I'm trying to fix it.

Just done another check using Wammer's EAS sheet, with the silencer off, all doors closed and EAS running, once it hits 60psi PSSSSSSSSSSSSSS all the air comes out of the block and I can't keep my finger on the hole. These NRV's are not sticking, they have new o-rings, both fitted today.
Anyone any ideas please?
Thanks
Hoppy

PS I have tried searching but it keeps telling me "the search could not be completed please try later".
Click to expand...

Does the compressor carry on running whilst air is being expelled?
 
Battery is on charge now guys, I think my new radio might be a culprit here, it has a powered DAB antenna, so even though it's off it might not be, so I'll remove it tomorrow and restart investigations.
thanks for the help so far :D
 
Mukiwa said:
Hi, no, I checked them and then double checked them on both blocks.
Click to expand...

Only one NRV can effect tank filling and that is NRV 1. NRV 2 prevents air from the bags passing into an empty tank and NRV 3 prevents high pressure air from the filling process being forced past the deflation exhaust valve into the corner solenoid gallery.
 
Morning all.
  • Charged battery all night
  • Fitted battery
  • Turned on and the tank started to fill
  • EAS appears to be working
When I took the block apart yesterday (the first time) I found white dessicant powder and a couple of balls blew out of the block when I sprayed compressed air into it. I then dismantled the dryer container and found that I'd put the lower gauze / filter the wrong way round so some of the balls had got through the gauze. That has been remedied and I stood myself in the stupid corner for overlooking that. Gauze first, felt second at the bottom :rolleyes: I did blow out the pressure switch with air but nothing came out of the hole.

Questions to the 3 wise men and I haven't read this anywhere:
  1. When I replaced the pressure switch, with doors open and engine running EAS filled the tank to 140 psi. Now it only goes to 110psi. Any idea why?
  2. Once the car is at normal height the pressure in the tank is around 75psi. Whilst the system is running does it ever fill the tank back to 140psi or so, if not, why not?
  3. I bought an OEM from Island 4x4, Air Suspension Air Pressure Switch (OEM) ANR3902 £29.99, are there better ones and do they go off over time?
Thanks for the pointers as well guys, I'm going to be keeping an eye on the alternator output as well.
If the EAS behaves today then it's top o ring swap on the FIP :D
cheers,
Hoppy
 
IIRC compressor should cut out when pressure gets to about 120 psi - the figure is in RAVE somewhere. On my current valve block it seems to go a bit higher, closer to 140 psi and has been for years so wouldn't worry too much.

You need to get all that dessicant out of the valve-block though. It'll stop the ends of the solenoids from seating properly and introduce leaks - odd behaviour!
 
Mukiwa said:
Morning all.
  • Charged battery all night
  • Fitted battery
  • Turned on and the tank started to fill
  • EAS appears to be working
When I took the block apart yesterday (the first time) I found white dessicant powder and a couple of balls blew out of the block when I sprayed compressed air into it. I then dismantled the dryer container and found that I'd put the lower gauze / filter the wrong way round so some of the balls had got through the gauze. That has been remedied and I stood myself in the stupid corner for overlooking that. Gauze first, felt second at the bottom :rolleyes: I did blow out the pressure switch with air but nothing came out of the hole.

Questions to the 3 wise men and I haven't read this anywhere:
  1. When I replaced the pressure switch, with doors open and engine running EAS filled the tank to 140 psi. Now it only goes to 110psi. Any idea why?
  2. Once the car is at normal height the pressure in the tank is around 75psi. Whilst the system is running does it ever fill the tank back to 140psi or so, if not, why not?
  3. I bought an OEM from Island 4x4, Air Suspension Air Pressure Switch (OEM) ANR3902 £29.99, are there better ones and do they go off over time?
Thanks for the pointers as well guys, I'm going to be keeping an eye on the alternator output as well.
If the EAS behaves today then it's top o ring swap on the FIP :D
cheers,
Hoppy
Click to expand...
Tight begger, fit a new dryer or you will have constant problems with powdered desiccant clogging up the valve block. Not expensive. I replace every 3 years or so.
If the EAS is working and you had not fitted a gauge, you would have been happy.:rolleyes: Fitting a gauge adds potential leaks and the stress of knowing too much:rolleyes::D:D:D
 
I agree ^^^^^^^ throw the pressure gauge away,. pressure switch should be open at or below 110 PSI (compressor on) and closed at 150 PSI (compressor off) plus or minus 5.6 PSI.
 
The desiccant is new I only changed it about 3 months ago, I did a full EAS refurb, airbags, block, desiccant and compressor. I got the dust out of the desiccant by pouring it between containers in the outside with the wind blowing, just like the old threshers. I also fitted my spare pump that puts out a fair bit more pressure (both piston seals, orings and barrel's are new). I can feel the difference with my finger on the output.
True knowing too much is like self diagnosing an illness by Google! With this car it's a cross I will bear hahaha :D:D

Anyway it held up last night, no drops in corners or pressure.

FIP o rings top & middle swapped. All dry, no leaks so far :D
 
Mukiwa said:
The desiccant is new I only changed it about 3 months ago, I did a full EAS refurb, airbags, block, desiccant and compressor. I got the dust out of the desiccant by pouring it between containers in the outside with the wind blowing, just like the old threshers. I also fitted my spare pump that puts out a fair bit more pressure (both piston seals, orings and barrel's are new). I can feel the difference with my finger on the output.
True knowing too much is like self diagnosing an illness by Google! With this car it's a cross I will bear hahaha :D:D

Anyway it held up last night, no drops in corners or pressure.

FIP o rings top & middle swapped. All dry, no leaks so far :D
Click to expand...
You will live to regret using the desiccant you describe.
 
Datatek said:
You will live to regret using the desiccant you describe.
Click to expand...
It was a proper refurb kit Datatek, well as far as Ebay kits are, the only powder was where a few balls got munched by the gauze. Only a few got through but it was enough to mess with the block. There is no powder in it now at all.

I saw some white crap blow out of the block and I blew out every single valve on the block. I'll get some more ordered. Are all the balls the same size or do some kits have bigger balls? I'm guessing it's due to surface area and absorption but it would make more sense to have balls bigger than the holes in the gauze, I bet I'm not the only one that's made the mistake of putting them the wrong way round on re-assembly.
 
Mukiwa said:
It was a proper refurb kit Datatek, well as far as Ebay kits are, the only powder was where a few balls got munched by the gauze. Only a few got through but it was enough to mess with the block. There is no powder in it now at all.

I saw some white crap blow out of the block and I blew out every single valve on the block. I'll get some more ordered. Are all the balls the same size or do some kits have bigger balls? I'm guessing it's due to surface area and absorption but it would make more sense to have balls bigger than the holes in the gauze, I bet I'm not the only one that's made the mistake of putting them the wrong way round on re-assembly.
Click to expand...

Big balls are very uncomfortable with tight underwear. Biggest problem with powder from desiccant is that it forms a crust on solenoid valve seals.;):D
 
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