I'm currently rebuilding a 4.3 Mercruiser boat engine, a V6 that is a marinised version of 3/4 of the 5.7 V8 small block Chevy engine. If you think some of the design features on a P38 are bad, you want to try working on one of those......

The sensor is on the lower of the two aluminium pipes that go to the heater matrix next to where the O rings live. It isn't unknown for the connection to fail so unplugging it and giving a squirt of contact cleaner is often all it needs.

I'll be completely honest, having seen the bottom ripped off a brand new radiator because the holes didn't line up so it was under tension, I've never refitted them. The rad is held in place at the bottom by the pegs and rubber bushes, at the top by the slotty things and gravity. Even if you managed to turn the car upside down, I doubt it would fall out (although the security of the radiator would probably be the least of your worries if the car is upside down).

No, there's no gasket between axle and hub, they just go together dry. Never known them to leak from there either so obviously don't need one. Thinking about it, there's the oil seal in the axle and the wheel bearings are sealed so there shouldn't be anything in there to leak out in the first place.

I've considered taking a mould off a backplate and making some up in fibreglass, problem is finding a backplate good enough to take a mould from (and no, I'm not spending in excess of 100 notes for one to use).

Certainly looks a bit on the crusty side but at least it isn't leaking oil so is only on the surface. Of course now you've caused yourself more problems when it comes to separating the axle from the trailing arm as it is no longer secure so you could end up chasing it around the garage. Hub bolts usually come out easily enough as long as you can get a good grip on them with a socket. I've got a set of these https://www.machinemart.co.uk/p/5-piece-bolt-grip-set-expansion-set/ and the 13mm one is almost worn out now. The more grunt you put on them, the tighter they bite.

Tell you what though, your disc protector backplates are better than mine. One of mine has come free from one fixing and is flapping about so clanks every time I go over a bump. I'll need to change the rear pads in the not too distant so I'll deal with that then.

Crossovers should be passive so no power there. DSP amp completely removed so how come the speakers are producing a whine? Is it possible that the output stage of the head unit is permanently on even when it appears to be switched off? You could try completely disconnecting the power to the head unit, both permanent and ignition switched and see what affect that has.

There must be an amp that is still powered in there somewhere. You say the amp is bypassed, is this the DSP amp in the boot or the 4 individual door amps? There is a turn on signal from the head unit that causes the amps to be switched on (there have a permanent supply but stay off until a signal is seen on the turn on line). On an aftermarket install, but still using the amps, that would be connected to the electric aerial line. If you aren't using the amps, then there is no need to power them. They can't be fully bypassed or they wouldn't be connected to the speakers. It all depends on what you have and how it has been wired.

Hmm, just realised. 10 stone plus a 5 foot bar equals 700 ft/lb, no wonder there's been nothing I haven't been able to get undone. Bouncing up and down on the bar means I've probably been able to achieve 1000 ft/lbs!

The most important bit, and often overlooked, on the back end, is the Panhard Rod bushes. If there is slop in them they allow the axle to move from side to side resulting in some very odd handling characteristics. I've never taken rear trailing arms off but have swapped a rear axle. The two bolts holding the axle to the trailing arm were a little on the tight side but a socket with my 5 foot bar on the end (an old front track rod bar) and putting my feeble 10 stone weight on it shifted them. If I remember right, the rearmost bolt was a bit tight to get a socket on due to other stuff (calliper carrier mounting?). This was an axle with a noisy diff, leaks from both oil seals and an oil leak from the weld on the diff housing so swapping the whole lot from a breaker was the cheapest and quickest solution. Especially when the rear discs were in a far better state than the ones on the original axle. However, having seen the pictures of the amount of rust you have on the underside of your car, I appreciate you might have more of a problem......

Just had a look under the Ascot. It appears to have had a sidestep on the passenger side at some time in the past and the brackets are still there. Not only are they there but are far better than any that I've seen pictures of. Rear one has obviously been clouted against something but if they were in the same state as the others pictured, would have just crumbled away. They're yours if you want them Chris.

The Ascot has obviously had side steps on it at some point in its life, or at least on one side anyway, as the brackets are still there. I'll have a look at it later this week to see if they can be got off without resorting to the angle grinder.

Pull the pipes out of the valve block, that'll let pressure of the rear springs, pulling the pipe off the tank won't do it as the valves in the block will still be stopping the air from coming out.

I've got about 7 brand new, genuine, white clips for the top screen finisher if you want them. They came in packs of 5 and I was convinced it needed 11 so ordered 3 packs only to find that it only needs 7 or 8. I found the easiest way to fit them wasn't to fit them to the finisher strip and try to slide them into place as RAVE says but to fit them to the pins then slot the finisher downwards onto them. If the finisher isn't held against the screen the wind whistle is really annoying. Drop me a PM with your address and I'll bung them in the post.

I've known a number of the currently available Dunlop branded pumps to fail in a pretty short time. Although they look identical to the originals, and parts are interchangeable, they just don't seem to last. Found one where the bearing had broken up completely and sucked bits of it into the compressor and wrecked the lot.

Marty fitted a Viair but I think his was a much bigger one, a 440 or something, and he made up a bracket so it sits beside the box rather than in it. But he also added a hose to the rear with a quick release connector so he could use it for blowing up tyres too. The 380 doesn't look much larger than the original so it might be possible to alter the mountings and fit it inside the box. Usual cause of noise is the washers being fitted the wrong way round. Bottom ones have the concave side downwards while the top ones have the concave face upwards.

Can't help on the size of the connection and could do with finding out myself. I've recently acquired a job lot of valve blocks so will be spending a fortune of X8R rebuild kits and need to make up some sort of test rig for checking them once done. Using a spare pump as a source of pressure will be a lot better than my well knackered tyre pump.

Yes, air springs need to be empty anyway, or at least have insufficient air in them to support the car at Access height. I start with the car at High, jack it so the first set of blocks can be fitted, then use the Nano or EASUnlock to open the valves and let the air out so it drops onto the blocks. After that lift on the jacks take the blocks out, fit the next set, drop it again and so on.

380C might be better as it is rated at 200psi and not 150psi like the 350C. The pressure switch should cut out at 140psi so a compressor only capable of 10psi greater might be a bit marginal.

Even the plastic can bite too.....

Usually they only start to fail when the gaiter splits and lets the grease out and dirt in, the sort of thing that would be picked up immediately on an MoT test here. I've never had one need attention on the 4 P38s I've owned or any on the ones I look after for the owners. Mine are still the originals too. As Dave says, just treat it gently, when it is knocking it's making things worse, when quiet there's no additional wear taking place.

Either both rear springs are the same age and have both started leaking around the same time or your valve block needs a rebuild.

As you suspect, it might be that the pressure switch is a bit keen, it should be open at under 120 psi and close at 140 psi. I've just acquired a number of valve blocks and intend making up a test rig so I can rebuild them with new O rings and diaphragm, check the driver packs for correct operation and leak test them. It won't take a lot to check the on/off pressures on the pressure switch while I'm at it.

Had a thought after posting my last, all EAS movement is inhibited when the brakes are on (for the first 3 minutes anyway), so it isn't going to do anything under braking. I tend to leave it in D when stationary and have noticed that after 3 minute delay of sitting in traffic and not moving, it will suddenly wake up and adjust the front but not before then.