My suspension error light had been coming on for weeks, so I ordered up Bagpiping Andy's kit for my 05 XJR and got after it this weekend.

I removed everything just fine. The adventure began at my workbench. I brushed and soaked the Torx bolts with WD40 and let em sit. One came off just fine, the other one sheared off level with piston casing. I put it in a vice and put a punch in the middle, tapping did nothing. I took out the screw extractor drillbit, drilled into the old bolt end just fine, but when I flipped the bit and drove the engaging/extractor end in, it wouldn't budge. Put an adjustable wrench on the bit - nothing. It was like the sword in the stone. Put a driver on it, and sure enough THE END OF THE BIT SNAPPED!. So now I had a steel donut with a carbon steel center. Ended up having to use a dental handpiece and a dozen or so super coarse diamonds to get the bit head out. Still had the donut.
I went out and bought a higher quality screw remover (long, tapered with a square profile). I put a torch to the ring a few times to soften it and gently tapped and threaded the remover into the donut. I put and adjustable wrench on the end to unscrew everything out - - - wouldn't budge and kept slipping!! Soaked it in WD40, let it sit, put wrench on it - - - SNAP!! Another carbon steel bit stuck. Couldn't tap it out/retrieve it. Ended up using a Dremel with chainsaw sharpening bits to grind through. It took hours, and now I have a piston/cylinder full of shavings and dust, and an enlarged hole.

A couple of questions: what the best way to clean everything out?
What size should I tap/thread the casing to? What kind of bit? I assume I'll be enlarging it and then threading in a sleeve that fits the included Torx?

Oh, and to top it off, one of the 10mm mounting post nuts locked and sheared off. I only have enough length to mount on the top bracket, but nothing to retain it on

 

I can't help with that situation but FYI WD40 is a terrible penetrant, it has very few uses in my garage. Use a real penetrate like http://amzn.to/2aqw0tv

Another trick I learned of is to use a small propane torch and before trying to remove the bolt heat the area up, then dab a white candle on it, the wax will wick it's way into the threads and make removal easier. I plan on trying that next time on rusty bolts.

 

That a good tip!

I ended up cleaning everything really well, drying it and pluggin up the defect with Epoxy. Once it set, I tapped and Threaded it.

I remounted and connected everything except forgot to hook up the exhaust valve. Car drove OK, but stiff.

Had Mechanic wipe all the codes, he said car freaked out a few times and they had to start and restart a few times.

i reconnected the exhaust valve after work. Air suspension fault light disappeared!!!

--- For 5 min. then it came back
--- then the Red light came on
--- And now my rear is sitting bottomed out.

What can I do?

 

Read the codes again.

Sounds like the compressor is not running?

 

Figured it out. I noticed there was a hiss coming out from under the hood. It wasn't the shocks/sensor mounts, so I turned my wheel left and unscrewed the three Torxx in the front of the wheel well. There it was. Loose outlet hose. Had to unmount everything and evaluate it...luckily nothing was stripped so I remounted properly. Good to go today!

Epoxy seal is holding up perfect so far too.. whew!