1998 XKR:

Does anyone know what size the steel brake lines and connection fittings are on these? Are they metric or imperial? (The ones in question are the rigid main brake lines running from the ABS pump to the wheel wells, not the flexible lines going to the calipers.)

Our car failed the NCT on brake line corrosion at the rear so I will probably need to replace a section, most likely somewhere in the rear subframe area. I need to pick up the brake line, some fittings and a flaring tool. I haven't had a chance to look at it myself yet so I don't know how bad it is. They are known for failing cars on the appearance of light surface rust on brake lines so it could yet be nothing to worry about.

The NCT is the National Car Test in Ireland, which is a glorified version of the MOT in the UK. It's pretty thorough in terms of checking for safety items and environmental stuff and has to be passed annually for cars over ten years old. It still relies on human beings to make judgement calls on some stuff though so one person's serious corrosion can be another person's light surface rust...

 

dhog4n -
I'm pretty sure they are "standard" 3/16 pipe. You can replace with steel, kunifer or copper. Manufacturers used steel partly because it's cheaper than copper or copper alloy, and partly because it keeps its shape and is easier to install as part of the production process.
Have a good look first - a bit of surface corrosion can be wire-brushed off and (your call obviously) given a coat of waxoyl or similar.
Depending on which pipe(s) need replacing, it might be easier and possibly cheaper just to get the Jaguar replacement (S N G Barratt is a good place to start).
If you decided on the DIY route, you will need pipe, a small pipe cutter, and a flaring tool. I used a Draper 23313 which worked (surprisingly) well - slightly more expensive than some of the Chinese stuff, but coped with Kunifer and steel.
I haven't done any pipes on my XK8, but had to replace part of two rear pipes on an old Mercedes ML.
Bottom line - if you can get at the pipe, and it's fairly easy to remove, then it's probably going to be easier and cheaper just to replace the whole lot. If the pipe is difficult to access, then it may be easier to cut out the rusted section and replace with new pipe, but you will spend £50.00 ish on tools, pipe, fittings etc.
Cheers,
David.

 

Go Kunifer (Cupro Nickel) for the replacements and it's done forever.

The DIY approach is easy with a pipe bender to assist with shaping:



You can soon replicate the original shapes after a little practice.

Graham

 

I opted to get someone else to do this job this time. It also gave me a chance to get the car up on a lift for my first proper look underneath. You can't see nearly as much using axle stands.

The mechanic was impressed (and I was relieved) with the condition for an ex-UK car. (They have used salt on the roads in winter there for a long time but we only started adding salt to grit in Ireland in the last five years or so.) There are two rust repair patches needed to the floor pan, each about six inches square which will be taken care of in due course.

The brake line had some surface rust over about 4 inches of line just in front of the drivers side rear wheel on the floor pan but was in good order. This section was replaced with as it would not pass the NCT retest regardless of functionality.

There was an engine bay noise which I had convinced myself was from the AC pump as it was coming from that area and the AC hasn't worked since we got the car. I had asked him to take a look to diagnose. It turns out it is chain noise, so that job will be done in the next week or two. I had the rocker covers off about a month ago and the upper tensioners are the aluminium type, so it must be a lower tensioner causing the problem. The holiday fund is going to take a hit, but it's worth it to keep the car on the road.