This afternoon I jumped in the XJL to visit a friend and while I was reversing off my drive the brake pedal fell to the floor. My first reaction was to pump it, with absolutely no pressure or braking effect. Fortunately I was going about 2mph at the time so the park brake quickly stopped the car before it rolled into the road.

The problem was immediately obvious once I jumped out by the large pool of brake fluid running out of the rear RH wheel. After the quickest wheel removal I have ever done I found that the caliper bleed nipple was missing, and subsequently located it further up my drive where it must have popped out. With quite some force too judging by the brake fluid running doen the rear-top of the wheel arch liner.

Examining the nipple and the caliper it was evident there was no thread left in the caliper at all for the entire top 3/4s (the actual mating surface). It had all come out with the nipple as little rings of thread which in my mind could only happen if it had been massively over tighened. Needing to stem the leak rapidly to save my drive and not having anything to clamp the hose without damaging it, I cut the compression end off the nipple and plug welded the hose end shut so I could make use of the end 1/4 of unused thread that was still good. (I will not be driving the car until it is repaired.)

The brake fluid was changed at the last dealer service in July, and as that would have required them to loosen the nipples to bleed the old fluid through that must have been when it was over tightened. I have not yet checked the torque on the remaining three nipples but will before I drive it again.

What concerned me was how I had no brake pressure at all (the vehicle did not slow until the EPB was applied). I thought on modern ABS-equipped cars the modulator split the oposite corners into separate hydraulic circuits so if one was to fail you could still safely bring the vehicle to a stop. That there was a total failure was quite frightening given that I use that vehicle to drive to my office multiple times a week and the nipple was able to blow out with only light braking while reversing off my drive. I shudder to think what would have happened if I was coming off a motorway slip road when the nipple blew out.

I can't understand why there was no pressure, unless either the vehicle was going too slowly, or because it was in reverse rather than a forward gear?

The car has only ever been main-dealer serviced from new, and although I do a lot of work on my cars myself I have not touched the brakes on that car. Needless to say some extremely strong words will be shared with the servicing dealer in the morning. The outcome could have been very different - it is actually hard to think of a better scenario than what happened.

Worringly, the same dealer changed the brake fluid on my FTR just over a month ago. I'm tempted to lift that and check the nipples are not over-torqued.

I hosed down the wheel to try and save the paint and it looks ok. I gave the suspension and wheel arch liner a rinse down too. My concrete block drive however was not as fortunate. I tried a brake cleaner solvent which allowed me to remove the excess fluid, and cement to soak up the fluid from the pores before rinsing it all off, but there are still distinct stains where it ran onto it. I'm hoping they will weather down if left exposed to the elements.

The main reservoir was just above the min line. I check the levels every couple of weeks when I clean the car and it was just under the max line at the last check, so it looks like about 150-200ml of fluid was lost.

On the plus side - my rear RH brake caliper and hub are now almost spotlessly clean from cleaning up the spilt fluid. I'll have to clean the others now as it puts them to shame.

 

Your a very lucky man! Can't imagine torquing down a bleed screw to that degree as to strip out the threads of the caliper. Unbelievable actually. Wondering like you if the same mechanic that serviced your XJ brakes is the same mechanic that serviced your F type, definitely find out and have both cars checked. I also hope it is not a caliper issue with soft metal issue.

 

I was actually in shock this morning when I phoned the dealer. If it had happened at almost any other time the outcome would almost certainly have been a lot worse, and potentially I wouldn't have been here to post about it. I really hope it was a one-off slip up with a single nipple and not a new tech who who made a habit of it.

The car is being collected by noon today to be inspected and repaired. At this point obviously they have not admitted any liability but they recognised they did change the brake fluid barely two months ago so I can't see how they could wriggle out of it.

I will get my torque spanner out and check the F-Type nipples this afternoon.

I was shocked when I picked up the nipple as the thread from inside the caliper was attached to it like a tiny spring coiled around the nipple threads which fell away when handled. Obviously the nipple is a harder metal than the caliper for that to happen, but what do you mean when you say "caliper with soft metal issue"? The caliper looked original as it had quite a bit of dirt baked on the mounting part behind the disc. Going by the service schedule it would have had the fluid changed three times after the factory fill.

 

A brief update -

The car was collected earlier this morning and taken to the dealer. They just phoned me to say that all of the remaining three bleed nipples were over-torqued to around 25Nm. (Nearly double the 14Nm they should be.)

Given they changed the fluid only two months ago they have accepted responsibility for over-tightening them and as the threads in two of calipers out of the four have been visibly damaged they are going to replace the whole lot to ensure no more failures down the line, plus new pads and discs on the rear as the RR had been covered in brake fluid.

They cannot explain how it happened, but it seems likely that their torque wrench was set incorrectly as they assured me they do use them on all screws and bolts where a required torque is specified, and they have a chart in the workshop with the correct settings listed. As they appear to have all been the same that does sound plausible to me. Maybe a metric vs. imperial mix up?

They'll drop me off a loaner XE in the morning. They offered an XJ, but I quite fancied test driving an XE.

I've not looked at my FTR yet and might not get a chance to this evening as it is raining here and I need to lift it on my drive. I think it is highly unlikely it will have the same problem. For my peace-of-mind though I'm not driving it anywhere until I've checked.

 

Good on the dealer for making things right.

My brain still works in ft/lbs and in/lbs torque only so Nm means nothing to me.

14Nm is 10.3 ft/lbs
25Nm is 18.4 ft/lbs

The tech that tightened them to 18 ft/lb must have been a bit of a brute. That's a lot of torque for such a tiny fitting.

Does the UK now commonly work in Nm or still in imperial? If their hand tools have any age on the they'd be calibrated in ft/lb only. Perfect opportunity for confusion.

 

Hi Mikey,

Yes I am glad it is being sorted. Obviously excluding the fact that it should not have been necessary, I can't fault them on their service since. The car was collected from me 3 hours after informing them, and they called back with their findings about 3 hours later.

The only imperial measurements I know are the mile, and the stone. In industry we are almost exclusively metric here - the US, Myanmar and Liberia are the only countries that still officially use imperial. That said, most people over 50 here will work in imperial first and metric second so it is not as clear cut as that!

 

Canada is stuck in the middle of a Metric/Imperial mishmash too. There seems little movement to go fully Metric here, unfortunately. Living close to the US border means we also need to be aware of their unique liquid volume measurement system (US gallon). No wonder mistakes in conversion are so common.

 

Xdave,

Nice to hear it was proven as to what happened. You will now have a solid piece of mind having all new calipers fitted and of course new brake pads for the rear as a oil soaked pad is no good period.

I would simply have the dealer also recheck your F Type so the responsibility if anything is found is theirs. Be there when they check it.

 

The calipers on my X2350, (previous model to yours), are aluminium. It would be very easy to over-tighten and destroy the thread on these if you're used to cast iron. Are your's cast iron or aluminium ?

 

xdave, it is very possible that if the tech took a quick look at their chart and happened to skip a line up (or down), that could have very easily lead to the wrong torque value. Granted, I would also think that the "idiot check" should have applied to where the tech should have asked himself "gee, this sounds like a lot of torque for this small fitting?". Granted, I have seen stranger things happen.

The other option like was mentioned is the torque wrench that they were using has shifted cal through use. This is part of the reason why I use dial torque wrenches almost exclusively and not the snap torque style (aka, clicker style). The clickers will not tell you where you went if you happen to go slightly beyond the initial click. Also, the clicker style can more easily change their cal if they are not stored properly (some are required to be completely de-tensioned while others are required to be set to a specific setting to keep a minimum amount of strain on the internals). I have had more training on torquing things than I care to admit to. Granted, when you are torquing fasteners on a submarine that hold back the sea from coming inside the sub, you bet your !@#$ that things are done with very strict standards and you know why things are done the way that they are.

 

I have the XJL back again this afternoon with shiny new calipers all round and new discs and pads on the rear. Both parts of each caliper has been changed too (the hydraulic bit and the pad holder) which was unexpected but nice because the front ones were spotted with corrosion marks and looking tatty.

I have only looked from the kerbside with a torch but it looks like the brackets are original (expected) but the hoses look spotlessly clean so I think they have been done to. The schedule they gave me does not list the individual parts swapped over.

I only got to drive the XE loaner to the shops and back but it seemed a perfectly nice car. It was a 2.0l diesel, manual, RWD, prestige trim model with only 100 miles on it. I didnt like the cheap feel to the leather seats and doors (it felt like vinyl) and felt my X-Type seats where better finished. However the dash stack was really nicely arranged and with a manual stick and leather gaiter instead of that large black plastic piece fitted on the automatics it looked really tidy.

 

Good afternoon Xdave,

Thank you for your post.

I am sorry to learn of the concern you have posted about.

Please can I kindly request that you PM me with your contact details and and vehicle details and I will be more than happy to investigate this further for you.

Many thanks,
Amellia

 

At the weekend I took advantage of having spotlessly clean new calipers and painted them a colour that is like a dark gunmetal metalic brown. It's almost a metalic black but not quite. I did the same to my XJ6 years ago and found that colour hides the dirt so they always look clean. I also applied some "Jaguar" decals to the anti rattle clips on the fronts.

I didn't want red calipers on the car because I feel they would have looked out of place as everything else is grey (the wheels are the grey diamond cut Mataiva's), and the OEM cast silver finish never looks clean for very long.

Overall I am happy with the result. Pics attached.