98 Ls400 Brake Fluid Leak And Check Vsc

[Parrot of Doom]

Today while braking heavily to stop for a set of lights, at the end of a motorway, the brake pedal sank quite far to the floor. I've lost a fair bit of braking force. The car can still be stopped, but not anywhere near as easily as it should. It's also losing brake fluid. After a while, "check vsc" appeared on the LCD readout.

I managed to limp home and I've just checked all four calipers and pipes and can feel no wetness. So the leak is elsewhere.

Tomorrow I'm going to refill the reservoir and crawl to the garage to get it onto the ramps, to see if its underneath somewhere. But in case this isn't just a holed brake pipe, does anyone have any experience with this problem? The check vsc light makes me think perhaps something in the traction control has failed, a valve or something.

[steve2006]

It could be the low fluid level has tripped the check VSC light as the system will not be able to operate in this condition.

There have been cases of badly corroded front to rear brake pipes on the later LS400s which pass through channeling under the car making them difficult to see.

Another cause of invisible brake fluid loss is when the brake servo seals fail and the fluid gets sucked into the engine and burnt but this normally produces lots of smoke from the exhaust.

Personally if you are a breakdown club member I would call them out to get the car recovered to your garage rather than risk driving it in its present state, if you were to be involved in an accident things could get complicated if you were proved to be driving an "unroadworthy" vehicle.

What ever the outcome please lets us know.

[Parrot of Doom]

I found it, an obvious leak forward of the rear wheels, possibly on the driver's side. About 40-50 pumps of the brake pedal is enough to empty the reservoir. Also noticed a very loose piece of possibly heat shield right where the fluid pees out, maybe it has been rubbing.

I've dropped it off at the nearest garage and told them to sort it out.

Are there any unions on the way to the back brakes, or is the pipe a long, single piece? I may as well get them all done.

[steve2006]

That wasn't a bad diagnosis then, the pipes are one piece front to rear with a lot of twists and turns on the way, not a quick or easy job to do.

[Parrot of Doom]

£96 to fix. He said some of the other pipes were a bit corroded but that nothing was urgent. Next time its in (I need someone to angle grind the front ARB drop links off) I'll get the rest done.