LR4 2011. Took the car for the MOT (UK test) and it passed las October but they guy said the brakes felt odd. I bled them and it became as sharp as can be and would stop on a sixpence. yesterday, the brake pedal felt a bit odd - firstly very hard and when I had started the engine, fairly soft - too soft although the car seems to stop ok. Bled them again and it is now as sharp as ever. I seem to need to do this every 6-8 months. There are no leaks and no other symptoms. Any ideas why this could be? The vacuum chamber is fine. The car has done 40K btw
Thanks

 

That is odd. Wonder if a caliper piston seal might be letting air in when retracted, but not when under pressure (hence no fluid leak). When you bleed the brakes, are you seeing air/bubbles? More at one wheel than the others?

 

Are you changing the fluid often enough?

If you do not change the fluid (which is hygroscopic) your will get spongy. While you bleed the brakes you are also changing a portion of the fluid, which will help reduce the sponginess.

As well, your lines are likely leaking. I have a 2011 LR4 and the line ended up leading so badly, I was virtually pouring fluid straight from the can onto the ground -- so I had to replace them.

 

Yes - if the brake fluid is quite old (and, especially, if you live in a high humidity area), it will absorb water. Then, if using the brakes hard, I believe the water boils out and can leave air pockets in the system.

I guess one other thing - at the risk of stating the obvious - is to make sure your brake fluid level is not too low combined especially if you have badly worn pads. If you’re fluid level is low and pads are worn (high caliper piston travel), you can actually suck air in through the reservoir.

 

I think I will rebleed to check that one caliper is not giving bubbles. There are no leaks so a one way entry of air is a credible scenario.
thanks for the feedback