high pitched screeching of brakes

[martin70]

There is a high pitch screech when I apply brakes?

I had the break fluid replaced but the cap on the fluid box was not put back on. It ran around like this for 6 months before I noticed

I was told by one mechanic that moisture would have got in and this will cause eventual rusting of breaks etc.

The mechanic that forgot to replace the cap said that this should not be a problem. At the moment I have the break fluid covered but I may be imagining it but ther seems to be a schreeching sound that is not too loud but a little annoying.

A bit worried and any advice greatly appreciated.

[gasace]

Hi most brake fluid caps have a vent hole to allow air to pass through, so not having the cap should not be a problem as long as nothing (dirt etc.) has got in. It is because brake fluid is open to air that it requires replacing every few years, as it does over time absorb moisture, but this will not lead to rusting, what it does is lower the boiling point of the brake fluid leading to a loss of brake power if the brakes are used hard (long decent) The screech is likely to be: 1 worn out pads 2 damaged discs 3 no lubrication on the back of the pad (this is the most likely, and the cheapest)