Foot brake failure

[PaulGover]

Does anyone know of weaknesses in the foot brake system that cause a very long pedal, hardly any brakes, and (later) "low fluid level" warnings?

I'm guessing a flexible hose failed, probably a combination of age and me replacing the front calipers disturbing things. I haven't located the puddle of fluid under the car yet! I know failed brake hoses were discussed in a thread on this forum a little while back - indeed, I contributed to it, and recommended changing hoses regularly.
(Of course, I didn't change the ones on my X350. "Do as I say", not "do as I do", as my old Dad used to say.)

[PaulGover]

Found the culprit, and it wasn't me, honest! No leaks from anywhere near the front calipers I replaced.

There's a rigid steel brake pipe from the ABS control valve block (RHD car) that runs across the top of the air-con condenser, then disappears down by the engine and AFAIK goes through the LH Front wing and connects to the flexible hose to the LH Front caliper. It's leaking at the RH end - I think it's fretting with the pipe clip that's presumably there to prevent fretting....

Anybody know if it's a DIY job to replace this? Extra gold star if it can be done on my drive with a trolley jack.... It looks like the air cleaner at least has to come off to give access, but knowing Jaguar, it might be an engine-out job -- or worse...

[PaulGover]

OK, so I repaired this in my drive. Getting access was relatively easy - removing the air cleaner and the radiator mounting brackets gave access to the top of the air conditioning condenser, where the offending pipe crosses. I couldn't get at all the pipe, as it goes under the wing to the caliper, and you can't easily get the front of the car on stands using just a trolley jack. So instead I just made a cut at a convenient point, and replaced the corroded length from the ABS control unit, and joined it to the remainder (in pretty good condition because of the plastic coating) using a proper female brake pipe union.

I used a length of copper brake pipe from a 25 ft reel I already had from Halfords.

You need one special tool: the Draper DIN flare tool. This is available from many sources on the Internet - I got mine from Machine Mart. All the 4.75 mm / 3/16" brake pipes on the X350 use the DIN flare, so one tool is good for everything. It's very easy to use - use a pipe cutter to get a square end (I used one from B&Q costing under £5). De-burr the end. Not forgetting to slide on the union bolt correctly aligned, insert the pipe in the tool and finger tighten the clamp bolts, screw in the depth gauge to push the pipe back the the right depth, and fully tighten the clamps. Lubricate the forming tool with the supplied grease and screw it in fully with a spanner, remove and dismantle the tool and Bob's your uncle, one neat DIN flare, with the union bolt behind it. I got two straight unions from this shop on eBay for less than £4.

First step is to cut and flare the old steel pipe, remembering the union nut. The pipe cutter and flare tool work fine on this steel. Flare one end of the straight length of copper pipe, then bend it to shape, trim to the exact length add the union nut and flare the other end. Join with the union. Undo the connection to the flexible hose at in the wheel arch, and pump through some brake fluid to remove any swarf, reconnect and bleed the brakes.

I attach some photos of the tools and union used, the rusty pipe, and the resulting flare on the steel pipe. The copper flares are, of course, identical.

The single-handed bleed pipe with valve comes from Halfords - it's under the Motor Cycle parts list, but it worked beautifully for me - I just pumped five full strokes of the brake pedal, and that was enough.

The little round bit of steel is my improvised tool to strip the plastic coating on the steel pipe. The flare tool instructions say remove it for 6mm from the end before flaring - the tool is a 6mm deep hole 3/16" diameter (exactly the same as 4.75 mm) with a hacksaw slot off-centre to leave a couple of cutting edges - insert the pipe and twist. That said, the original Jaguar-supplied pipes flares had clearly been formed without removing the plastic coating, as you could see it on the outer half of the flare face, so it may not be necessary.

The strangely shaped steel tool at the top is a hand pipe bender, also Draper's, and it works much better than the ones with wheels as it's easy to use in confined spaces and produces smaller diameter bends - about the same as the original pipe.

[Andy P]

Thanks for that info Paul and the photo's,very useful .
Glad you got it fixed without too much hassle.
Take care and well done.
Andy