In all my years working on cars, this is a new one:

Decided to flush the brake fluid on my '00 XJ8. Haven't done it in the 5 or 6 years I've had the car, and don't know if it was ever done before.

Using a Motive pressure bleeder, started at right rear and got a lot of black fluid out no problem. Moved to left rear, and... Nothing. Even with 10-15 psi at the master, no fluid came out even with the bleeder removed. Tried my Mity-Vac on it, but no luck. Went ahead and did the fronts, and got the fluid flushed fine. Test drive was fine. Good pedal. And the pads on both rear sides looked about equal. I did crack the hard line fittings going to the left rear, and got fluid seepage.

So I suspect maybe a failed left rear rubber hose? Complete blockage maybe? Ordered new hoses and rear caliper rebuild kit, but haven't done the work yet.

Anyone ever have a similar situation?

thanks,
Mike

 

If the line was blocked the brake wouldn't work and the car would pull badly. It's probably just corrosion and sludge in the caliper at the base of the bleed screw. Have you tried stepping on the pedal with the bleed screw removed?

 

I had same problem on a 99 last week it came to me with no fluid or very low fluid in the reservoir so I started on the back wheel and I got nothing so I had someone pump the pedal and it started spitting but still that took a while then I finally started getting air out of it then I started getting fluid then I started getting foam , Discolored fluid then the real stuff by the time it was a pretty good stream but it took two minutes of fluid before I got that for same thing on the wrist it had discolored fluid inside it eventually that came out. I don’t know if it makes a difference running the motor but we tried that two to get the brake assist with it. It seem to help get the fluid out with the motor running the car now has brakes it was just fluid in the system with air

 

As you go through the process keep checking the reservoir so it doesn’t get more air in it. I was never able to use my bleeder I thought the same thing what the heck is wrong with this no fluid coming out

 

Well, mystery solved. As RJ237 suggested, it was a slug of crud at the bottom of the bleeder opening into the cylinder. Once I had the caliper off, and piston out, even injecting many psis into the bleeder opening wouldn’t blow it out. Took a small drill bit and hand drilled the blockage. The cylinder, piston, and seals were in great shape. No idea how that even happens. Very strange!!

 

This is why brake fluid change is recommended every now and then. I've fixed many hydraulic cluches with sticking clutch pedals only with fluid change. Every time fluid was turned to coca cola(pepsi) color. Next step is sludge.

 

Yes. Most car owners have no idea how critical it is to change the brake fluid every two to three years. That DOT 3/4 stuff is hygroscopic, meaning it sucks up moisture like a sponge. I've got classic cars that don't get driven much and I'm actually far more religious about changing the brake fluid on the calendar than the engine oil because I've seen brake fluid just go bad in the bottle, just from breaking the seal, using a small amount and then putting it back on the shelf, even with a tight cap. In a year, it will have already started to change color. I figure inside the brake system, with metals, getting hot, etc., its probably going bad even faster than in a plastic bottle on a shelf.