Where's the best place to put a T-piece for a pressure gauge for the EAS and what hardware do I need?

Does anyone on here have a rig to bench test rebuilt valve blocks?

Spot on as usual GD. This is a parallel thread to my other post where we pulled fuse 29 and one corner sagged. I thought it would be easier to find with a dedicated title. Cheers for the guidance. I'll buy some aerosol air dusters as we don't have access to a compressor with a tank... Unless I fit a T-piece to my car!

Sooz is refurbing the nearly new compressor from her car and found telltale white powder from failed air dryer desiccant. That explains the premature failure.

She's 75% through rebuilding a different valve block soon that's sorted.

We have air dryer refurb kits including foil packed desiccant.

Two questions:

1 Where else can we clean up residue while we're changing all the major elements? I'm hoping most has been blown through into the air springs.

2 Is the block currently on the car buggered or can it be cleaned and refurbished?

Backstory: We have two P38s. A Black/grey interior Vogue 2000(W) on 125k and an Oslo Blue/cream interior 2001(51)on 67k-ish. We've had mine (the Black one) 6 or 7 years and Sooz for about 2 years. Both cars have replacement OE air springs. During that time, we've seen off 4 EAS compressors. Enough is enough.

We bought the current compressor in the blue car brand new from a reputable vendor with solid feedback and the serial number checked out with Dunlop. First it became very noisy, then the cut-out failed, all within a few months. It currently has a replacement glommed on the outside and spliced into the loom on the compressor cabling. But there's more.

The pump still goes through phases of loud vibration, then quiet. We stripped it and eye-balling it all looks fine. The loud phases reverberate though the whole car - makes a sound like something in the wheel arch, but it has done that in both cars so we know it is the compressor. We leak checked both cars by pulling fuse 29. Mine stayed up. Sooz sagged on one side of the back axle. Valve block and X8R valve block refurb kit are here awaiting her return. That explains, but does not excuse, the catastrophic failure of the pump after such a short time. I neither know nor care what's causing the noise or why the stat failed. It's going in the bin rather than waste the X8R compressor refurb kit in the workshop. As the blue car is completely stock, we'll keep it that way. We'll refurb the valve block and put the working pump from my car in there. Yes, my wife works on the cars with me. No, she's spoken for!

In consultation with the hive mind of the internet and Gilbertd, I've sourced a Viair 380C for the bargain price of £175. This has a 55% duty cycle and flow rate more than three times the stock pump. Vendor seems solid and I've used PayPal for added protection. Photos have disappeared from many of the threads I used to research this. The wiring looks (sounds) to be simple, with the orange wire now redundant and connected to the black ground wire, it's just a two-wire switched supply. However, If anyone has some pics relating to mounting and tidily hacking the existing enclosure, I'd be very grateful. I know I can mount it in parallel and keep the old pump as a bakup but I'm in Somerset, not Western Australia, so I'd prefer to go all in on the new unit. For our part, we'll take detailed pics and post back here for anyone interested in the pros and cons of what I'm about to attempt.

I'd like to finish with a simple question.

Does anyone known exactly what size and gender of NPT reducer I'll need to join the new compressor to the blue pipe?

Done. Found one for £175.00 including shipping.

Here, belatedly, is the pic of the cut-out thermostat stripped from an old pump.

I glommed it onto the outside of the pump with epoxy putty.

Gilbertd wrote:

The Viair is only slightly bigger than the original (which was a Thomas pump and not Dunlop as some seem to think) so could probably be fitted if the box was slightly modified but Marty has used the vacant space next to the box. Wouldn't be an option on a LHD car but plenty of space on ours.

You are referring to the 350C? I'm about to buy, so I don't want to get the wrong thing.

Okey dokey. I'll get a spare and a kit from X8R.

Springs are only about 3 years and 15k miles.

Okay. Left Sooz car (2001 Vogue) in high overnight.

Both rear springs have dropped around an inch.

Comments, please...

Is the relay everyone is talking about the black one under the passenger seat?

Excellent contributions from everyone. Thank you!

I realised the 15 percent duty cycle of the compressor amounts to 9 minutes in every hour. I'm pretty sure my car exceeded that by more than double while driving in Cardiff today.

I'm pretty sure the speed triggered changes alone would be over 9 minutes in some conditions. Of course the motorway miles would see it dormant.

I'll pull the fuses and start leak checking both cars.

Gilbertd wrote:

You've got a leak somewhere. Pull fuse 44 (pre-99) or 29 (99 or later) and leave it overnight. That will show you which corner is leaking and dropping. Then you will need to get the soapy water spray out and check the air springs, connections to the air springs and where the pipe comes out of the valve block for bubbles.

I assume that disables the entire system, including the checks triggered by the door switches?

Craggle wrote:

What, the pump runs every 20 - 30 minutes with the ignition off and parked up?

Sagging suspension overnight is normally air leaks. Air springs get perished or the valve block seals get old.

Craig.

The compressor only runs when driving with the Inhibit switch pressed. The sagging is overnight, ignition off, Inhibit switch still pressed.

The air springs were absolutely buggered when we got it two years ago. God knows how it passed the MoT they gave it at the dealer. They are all new.

Car is low mileage at 68k and garaged for most of its life, but I guess standing can do as much harm as high mileage.

Having successfully fixed the over temp sensor in my car (photos soon) we realised my wife's car has an issue.

Even with the inhibit switch pressed with the height set to Standard her compressor is running every 20-30 minutes and the car sags right overnight.

What are the first things to check in order of probability?

I was thinking mainly in terms of reliability. A cluster of things in the EAS have gone wrong of late. This seemed a likely candidate, Down there in the salt!

It is handy that failure is open, giving the option of piggy backing a new one. Thanks for the help. I was a bit down about this whole thing as the car was just back on the road. I was excited and on my way to a track day for a ride in a 440BHP M3, so this hurt. There's another opportunity at Thruxton on Tuesday and I found a 3rd pump in the workshop with a working sensor I can cannibalise

The light at the end of the tunnel is back on ... might be a train though!

Do people refurbish these or buy an off the shelf alternative? A lightweight corrosion resistant composite would be nice. Fittings are standardised, aren't they?

I'm planning a Viair upgrade next month. I seem to have several choices: 350C, 380C and 444C. I gather Marty's is outside the original box I'd like to put it inside.
Which would be the best fit?

Okay. Definitely going Viair but skint at the moment.

Does anyone have a link to the pictures and tips for replacing the over temp sensor in the compressor?
I found a couple and it's a mess in there. Motor brushes exploding all over the place. Do you switch the sensor or the entire board?

I had already ordered from the eBay link but he's away and can't post until tomorrow. That's why I was hoping to get one from RS. I suspect the photo on eBay has been doctored to remove the numbers. I'll post here when it arrives.

Found the sensors on RS but there are 4 with no clue which to pick. 12v obv. Closed when cold. But what temperature?

https://uk.rs-online.com/web/c/switches/industrial-switches/thermostatic-switches/