Hello guys!!

My brake light had been coming on and of for a couple of weeks and I thought that it was just s faulty level switch in the brake reservoir, but today I thought I would add a little fluid so I stopped by the Jaguar dealership and bought a bottle. Well I added the whole bottle and my light has not been coming on ( take note folks with you brake lights on, although your reservoir may appear to be full, it might not be)

Anyway, I am glad my light went of, but where did my missing brake fluid go? I can't find any leaks in the obvious areas ...

Help please!!

 

Might be nothing at all.

It's normal for the fluid level to gradually drop as the brake pads wear.

Pads wearing = caliper pistons moving further outward = more openn space behind the pistons = fluid moving into calipers to fill up the space = lower level in the reservoir


Cheers
DD

 

What all have you checked? The most likely places are the soft lines connecting the calipers (dont forget the rear), the calipers themselves, and the master cylinder (can leak out the back into the brake booster)

Thats not to say you shouldn't inspect all unions and fittings, but its gotta be going somewhere.

When it leaks at the pistons that gives it somewhere to go, but it usually gets flung about everywhere and hoses and fittings leaking in one spot will obviously leave a spot on your driveway.

There isn't much to the system, just follow every line up to its caliper and look for any wetness.

btw don't forget your pads wear down

 

yeah man definitely check that level before you change your pads, don't go compressing the pistons and force all the extra fluid out onto your fender and engine bay

 

If there is no visible leak it might be normal pad wear. You have to remember this car has 16 pistons to move and adjust, all with brake fluid.

 

This is only a 'Wild Guess' but could there be Air in the System?

As the Air finds its way to the reservoir and then leaks out of the System

The Brake Fluid level could appear to drop, giving the impression that you

have a Brake Fluid leak.

Its only a guess but maybe that could be possible?

 

Thanks for your replies !

Hopefully it's the pads wearing. ......They are relatively new.

I will probably know soon enough if the level goes down again. What worried me is that it took a whole bottle of the Jaguar brake fluid

 

Who replaced the pads?

The proper way to replace them is to open the bleed valve and push the pistons back, so perhaps whoever did it forgot to check the reservoir to see it was correct after replacing them.

Keep an eye on it and see if it moves again, you definitely don't want it so low it takes a whole bottle

 

It took 5 litres of Brake Fluid to Bleed the Brakes on mine, which I've heard is not all that unusual.

 

If there are no visible leaks around calibers, lines, master cylinder, then look to the vacuum sysem. (Brake booster)

 

Hi. I would be really concerned that it took a full bottle of fluid to top the system up. that would suggest that its more than pad wear. I suspect more like the master cylinder is leaking at the rear into the booster. A couple of members have mentioned to check the booster, but I don't think anyone mentioned that you might not actually get fluid leaking from the booster so there would be no obvious leaks there.


What happens then is that the fluid gets sucked into the inlet manifold & burnt by the engine, leaving little or nothing to drip & show signs.


Look at the exhaust emissions when the engine is well warmed up. If you give it some wellie, you might get white smoke from the tail pipe, but if the leak is slight you might not get any smoke.


You might get an endoscope down the hole that the vacuum hose NRV fits into. Alternatively, undo the nuts holding the M/cyl to the servo & try & ease forward far enough to get a finger or a mirror behind.


Best of luck.
Scotty.