I'm trying to get to the bottom of a strange ride height issue on my TDV8 which I think is contributing to uneven tyre wear. Even after calibration using my IIDTool the ride height varies across the axles and does so dynamically with the rear being particularly noticeable.

I've ordered new sensors and all three valve blocks and I think I'll change them all and re-calibrate (and get yet another 4-wheel alignment done as hopefully a consistent ride height will mean the alignment will then be meaningful).

The question is, are there any "gotcha" issues to be aware of when changing these items? It all looks to be simple plug and play stuff but that always makes me nervous

With the valve blocks, is it just a case of unscrewing the air lines from the block, pulling out the pipe and pushing it in to the new block? I understand that an olive might need removing from the pipe. Is this usually a tight fit? Thinking of the "fun" I've had with plumbing olives makes me winder if the pipe is likely to get damaged.

If the issue persists after this, I'll look at changing all of the spring/damper units too. Might be worth doing anyway as they're several years old now. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Be careful with the electrical connectors to the sensors. The plastic locks tend to break on the loom side of the connectors when you disconnect the sensor.

Thanks, I'll watch out for that. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Well that was annoying. Got it jacked up, wheels off, and couldn't get the bolts undone that hold the rear height sensors on. Even with a dose of WD40. Absolutely refuse to move. I don't want to force the issue however as it'll be fun changing them if the bolt heads get damaged so I've decided to put the wheels back on and leave it. I might have another look tomorrow to see if the WD40 has found its way along the full length of the thread.

The rear valve block is similarly a bit of a tight squeeze.

I'm thinking I shall just have to pay a garage to do the work. Bit annoying really. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Blow lamp

It's one option although perhaps a little overkill

I went and picked up a set of 3/8-drive torx sockets and I'll see whether that works better in the morning after the WD40 has a few hours to do its work. The electrical connector was also impossible to undo but might be easier to manipulate once the sensor is off the bracket. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Using a blow lamp isnt overkill, just warm it slightly and it will come straight out.

I've done that on bigger stuff once that I could get to easily but to get it in amongst the suspension looks to be a bit tricky. I don't have a torch just a burner-on-bottle type lamp that I use for the odd bit of plumbing.

A friend suggested smacking a slightly bigger bit in to the head of the torx bolt and then turning it. Again, this seems a bit "if nothing else works try it" type method.

It's not the end of the world if I can't get it to shift - I'll just get someone else to do it.  2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Yeah having a blow lamp that you can adjust is important if its in a tricky location.

Just hitting it can shock the bolt loose, so its not a last option id suggested a lot of wd40 or similar and a love tap with the hammer to shock the rust loose.

Worse can yeah pay someone but its not something i like to do

No, paying for a "simple" fix is not something I like doing either. But there's no point getting older if you don't get a bit wiser with it...  2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

RRSTDV8 wrote:

I'll see whether that works better in the morning after the WD40 has a few hours to do its work.