for those of you who change ur own front brakes, when changing the brakes and than pushing back the caliper piston do u OPEN the master cylinder cover or no? just wanted to know to be safe thanks in advance

 

I have before. I didnt the other day though. No problems. No leaks.

 

I never did.

 

never have, i am sure you will be fine either way

 

You should not do it that way, you should open the bleeder at that brake and let the fluid push out there.

That said, I've also done it your way because I didn't know any better and nothing obviously bad happened. But the correct way is not hard so you might as well do it.

 

Sounds like he does not intend to bleed the brakes, you generally do not have to bleed the system when just changing the pads. I've never opened the cover of the master cylinder when performing a brake job except to add fluid when bleeding. If you read the instructions for performing a brake job I don't believe the is ever a mention that the cover needs to be open. Although if you were to do it with the cover open it would not make any difference. I believe the master cylinder is vented so that the air displaced by the brake fluid will escape.

 

Like I said, *technically* you should open the bleeder and let fluid out at the brake when compressing the pistons, even if it's just to change pads. This isn't the same thing as bleeding the system, since you're only discarding the fluid that filled the caliper pistons.

But I usually don't do it that way.

 

Brake fluid is hydroscopic (absorbes moisture) and should be changed every time you do a brake job. That keeps the system clean and prevents corrosion which will cause your components to fail. It also helps to maintain a very firm brake pedal and fresh fluid has better temperature characteristics then older fluid.

It's cheap insurance for your brake system.

 

I don't know about doing it every time, but every 2 years it should be done in northern climates (Chicago, newyouk, canada, etc..) where you have hot summers and cold winters. another indicator is if your fluid is dark, it should be clear to yellow in color.

 

I just do a full flush before every track day.