So it does, thanks for that.

lrcat has been blocked for ages now as the https certificate has expired. I now use the genuine JLR site instead, https://parts.jaguarlandroverclassic.com/. There's also https://www.allbrit.de/ but both are online, no idea where a pdf version can be found.

Had a couple of hours free this morning and as the bench is set up for valve blocks, decided to check the next 3. The first one has a driver pack with one dead channel so was put to one side for later or for cannibalisation. Checked the driver pack on the second one to find all channels working so decided to give it a leak test. Putting air into the reservoir port it all came out of the dryer return port suggesting at least one of the NRV's wasn't sealing so took the end off. This is what happens if the desiccant in the dryer makes a bid for freedom......

Another one for the pile of maybe one day or maybe not.

Dunlop compressor is probably toast. If it drops with the bypass valves in either your air springs are getting towards retirement age or, more likely, you have a slight leak on the connection between the pipes and the valves. The pipes form a groove where the O rings sit so will start to leak at some point. Simple fix, trim a millimetre or so off the end and chamfer it with a pencil sharpener. Unless you have some serious leaks in the valve block then anything from the desiccant pack isn't going to end up between the solenoids, so what the green can be is anyone's guess.

In between the nice weather, I've been working my way through the stock of valve blocks I bought ages ago as I can do something useful inside. Got 3 that have been done and tested (it was 4 but I've sent one to Germany for Max) and another 7 to go..... So I'll have a few ready for fitting shortly.

Adding line in and Bluetooth to the Clarion was fairly simple but the main problem with the Clarion units was the display failing and they are NLA. You used to be able to send them to Clarion who would do a fixed price repair which included a new display, adding the line in and making them code free. I sent one to them about 5 years ago and they called me to say that all they had left was grade B displays and would I be happy with one of them. I said to go ahead and that unit went in the Ascot but had started to fail by the time I sold it last year.

If you still have your original DIN plugs there's nothing to stop you trying the Alpine and see how it works. I suspect it will be low on volume without the amps but you've got nothing to lose.

If your 98 had the Clarion it will have had a 10 way speaker output DIN plug, So the 4 channels plus the output for the sub. The Alpine will have an 8 way DIN connector with the sub output on a separate plug. Depending on how much has been changed to fit your aftermarket head unit, it might be plug and play but it might not. With an Alpine that had the DSP amp, you will need the door amps, or something to boost the output, that a mid line system didn't have, they were only fitted on the High line. Unless you intend installing the DSP amp as well, in which case it is far from plug and play, more like a total rewire.

I blasted the underside of mine with degreaser and a pressure washer before taking it for one MoT test. The tester looked at it and asked if it had any oil in it.....

You're right, I've got 6 or 7 that I don't consider worth using as they are badly worn. Most of the 12 valve blocks I bought don't appear to have had much use so the NRV's are in good nick. They came from a company doing off road conversions, and the main problems I have found with them are split diaphragm valves and bad connections in the driver pack to solenoid plug so not all channels were working. I leak test them initially and if the valves are leaking badly, put it to one side and move on to the next one. Any that appear to be good, I'll re-tension the sockets in the solenoid plug, replace the diaphragm and check the pressure switch to make sure that is working. Then replace the O rings and do another final leak test before declaring it good to go. So from those with leaks, I've probably got a few spare valves that weren't leaking.

Take the coils off the solenoids and see where the leak is actually from. I've known them to leak around the plunger seal, out from the bottom where they attach to the main block and even between the two halves of the valve itself. It's not as easy with the block in the car, particularly if the leak is on one of the bottom ones, much easier on the bench but that involves plugging the outputs so you can put pressure into it.

I bought a job lot of valve blocks and have been working my way through them, so could supply you with one that is all done and known good. Drop me a PM.

Your leak could be from the base or from the solenoid tube itself so it looks like you will be taking them apart again. I test them by connecting a compressor to port 6, where the reservoir would normally go, and opening all 4 corner valves and the inlet valve. That puts pressure into each outlet so I can bench test and look for leaks by leaving it overnight. If the gauges haven't dropped after 12 hours or so, they are good. If they have, then out comes the soapy water (as the weather has been a bit iffy recently, I've got 4 valve blocks now all ready to go for anyone that needs one). Doing it like this also checks all of the channels in the driver pack too. Then I can apply power to the 4 corners and outlet valve to let the pressure out.

Note that I test at 12-13 bar and as the system runs at a maximum of 10 bar, if they don't leak at 12, they aren't going to at 10 bar!

It's obviously worn and working too hard so is overheating. The big worry is that either the thermal switch dies so it goes off and stays off or by running near constantly it will wear itself to the point that it can't generate enough air.

Are you on your way out or heading back home?

It depends on how much you can get an engine for. An engine swap isn't difficult if you have, or can beg borrow or hire, an engine crane.

Cylinder 4 is a bit low compared with the others but not excessively so. Before my engine went to V8Developments, it was down to a consistent 110-115 psi on all cylinders. A bit tired was the polite description.....

If you run into problems on your way down south and are using the A1, I've got 2 valve blocks and a pump that I've rebuilt and fully tested sitting on the bench, so you could always make a pitstop on your way down. The second valve block is currently being pressure tested and is holding nicely at 13 bar, around twice the pressure it will ever experience in use.

No, the bonnet doesn't but all 4 doors and the tailgate should. Although thinking about it, having your foot on the brake pedal inhibits movement but after 3 minutes it gets bored and moves anyway, maybe some versions of firmware have a timeout on the doors too?

Errm, no. That should inhibit all movement. Does the Nanocom show it as open?

They will be. Unless the car is at the desired height, as soon as you start up it will open the rear valves and the inlet. It will always raise the rear first then the front. So what you should see is rear valves open, they close, fronts open then close and it will then repeat until all 4 corners are up to height so it will close all of them.

Take a 12mm open ended spanner too for the pipe to the pump......

Probably a lot better. I've seen a couple of the Dunlop branded ones that have been completely destroyed inside. No idea who makes them but I suspect someone in China as Dunlop don't make pumps themselves. The old, all black, ones usually just need a new seal and sleeve.

I bought a job lot of valve blocks and have worked my way through some of them. Initially I used the X8R kits but saw the same complaints you have obviously seen and I did have a couple of problems with the very thin O rings around the base of the solenoid plunger, so tried the 4x4airseals kit. I measured the size of these O rings and found them to be identical to the X8R ones. The 4x4airseals kit comes with a small sachet of silicone grease that X8R don't supply too so have used them since. Not all of the solenoids have the square seal under them which is why you only get a couple of them (in fact the latest 4x4airseals kit I have got doesn't include them) but as you say, they are only to keep dust out.

To be quite honest, just recently I have stopped taking the valves themselves apart to replace the solenoid plunger O rings. I have found that when you take them apart, the plunger will rotate so the groove worn in the rubber seal on the end then no longer lines up with the piece it should seal against so you actually create a leak that wasn't there in the first place.