Documentation

Vauxhall Corsa D balljoint and Lower Control Arm Replacement

Lower suspension ball-joints periodically reach the end of their useful life and need replacing.

They're rarely fun to do, but are (normally) quite simple. On the Corsa, replacing the Lower Control Arm as well is usually just two additional bolts, and may or may not be necessary (depending on your car)

This documentation details theĀ  process of removing and replacing your lower control arm and balljoint on a Vauxhall Corsa D

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Saab 9-3 Front Wheel Bearing Replacement

Wheel bearings don't last forever, and inevitably need replacing.

Saab 93's have a combined bearing and hub assembly, so replacement is - in principle - fairly straight forward, no bearing press required. The ABS sensor is also built into the assembly, so the procedure described here can also be used for replacing ABS sensors.

Although the procedure is quite straight-forward, if you're unlucky it can also be a bit of a pig. Although a hub puller shouldn't be required, it's advisable to have on one hand - unfortunately the driveshaft splines have a habit of rusting into the bearing, making it extremely difficult to remove the axle when required.

This documentation details signs of a failing front wheel bearing, as well as the process for replacing it on a >2003 Saab 93.

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Citroen C5 Dragging/Rubbing Caliper

I found some old notes on this on my wiki, and figured someone might find them helpful

There is a known issue with the Citroen C5, where the rear calipers may end up rubbing against the inside of the wheel (rear caliper corrosion syndrom).

Basically the issue is one of water ingress. Corrosion develops between the mating faces where the caliper is mounted to the suspension leg, and the caliper is slowly pushed out at an angle, ultimately causing it to rub against the wheel.

It's identifiable by metal being worn away from the caliper and/or the inside of the wheel.

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CentOS 8: Requiring a Yubikey OTP Press for SSH logins

Some 7 years back, I wrote a guide to requiring a Yubikey OTP for SSH logins on CentOS. In the time that's passed, the process has changed (a little), so this documentation provides an updated reference.

Although this is written (and tested) for CentOS 8, it should work equally well on CentOS 7 (and presumably also Rocky Linux) too.

The (increased compared to my previous post) flexibility of Yubikeys, along with their relative ubiquity makes them a fantastic candidate for two-factor authentication tokens. Modern Yubikeys can do U2F as well as using their proprietary mechanism, allowing them to be used with a wide range of software.

By the end of this documentation, we'll have configured a CentOS 8 server to require that a user provides a Yubikey press along with

  • Username AND
  • Account password, OR
  • Authorised SSH key

For brevities sake, the majority of this documentation assumes you want root to manage user's yubikeys - something Yubico call Administrative level managment - switching between the two is relatively straight forward, so details on how to switch "User Level" will be given at the end of the document.

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Vauxhall Corsa D: Oil Pressure Switch Replacement

Vauxhall Corsa D Failed Oil Pressure Switch

Also known as "My Vauxhall Corsa D is leaking oil from top left hand side of the engine", the Vauxhall (or in some markets, Opel) Corsa D has a known issue with it's Oil Pressure Switch failing.

After some use, they eventually fail and start to leak oil inside your engine compartment - worse, some of this oil can get pushed back into the wiring, and then drawn up into the loom via capillary action - left long enough, a failure of this switch will be followed by failed lambda sensors, airflow sensors and then ultimately, the ECU.

The part is cheap and simple to replace, it really is 10 minutes work.

Make sure you give your car time to cool down first though, you're going to be working in close proximity to the manifold - when that's at temperature it'll happily sear the flesh off your hands.

For those who prefer it, there's a video version at the bottom of the page.

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