Hi folks, I need your help please. I have an ongoing problem with the n/s front brake dragging slightly. I'm on the third caliper and third set of discs in under two years due to uneven pad wear and slight judder when braking at speed. I changed the pads this weekend. The pads I removed were close to the steel backs on the n/s but lots of friction material on the o/s. After new pads were fitted, with copper grease on the sliding surfaces (not the disc) I drove the car for ten miles and guess what: o/s disc was warm; n/s disc was very hot and too hot to touch! After reading the chat line some folk are suggesting a sticking air piston in the brake server due to corrosion? the car has done 235k miles but plently of guts left in her but is probably on the wrong side of the bath-tub curve. Any thoughts gratefully received please? Graham

 

Replace the rubber hose from the wheel well hard line to the caliper. The hose may look fine on the outside but may have collapsed inside and it is not letting the pressure off the caliper when you're not touching the brake pedal. I'd recommend replacing both. I bet if you take it off, you will not be able to blow through it.

 

Many thanks Dave. Seems a cheap enough fix and makes sense given that the caliper change probably involved clamping the flexi-hose. I'll try to do the job this coming weekend and will advise the outcome. And much better than changing the brake server!!! Graham

 

I hate clamping rubber hydraulic hoses for that reason. Especially older ones. I have a collection of rubber and plastic plugs from many many parts that I've bought over time. Most of the time I can find something that will slip over the end of the flared end of the hose and keep fluid loss to a minimum.

But what happens inside those hoses is that the different layers that make it the structure of the hose can break down and separate. Break fluid can work its way in between those layers and basically create an aneurysm of sorts internally and block off the return flow (when you take your foot of the pedal) because the back pressure is not nearly as great as when it is when you press down on the pedal to engage the brakes.