when changing breakpads.. is it recommand to open the break fluid cap or no?? can I change pads w/o opening the cap??

 

First it is "BRAKE"
Second.... it is not difficult to open the cap...so just open it.

 

i changed mine without opening the cap... i don't recall having to open the cap for install either. just compress the pistons when installing the brake pads and you should be fine. but during the install, bleeding the brake fluid is recommended.

 

If you take the resevoir cap off while compressing the caliper piston/s then you wont have to bleed the brakes. Thats how I've always done it on all of my cars.

 

No you do not have to open the cap when you change brake pads. All master cylinders have vented caps anyways. Also I am not so sure leaving the cap off of the master cylinder will bleed your brake lines when you compress the pistons.

Correction: It is a good idea to open the cap when you compress the brake pistons. It allows the air displaced to leave the cylinder as the fluid fills the cylinder.