No such thing as a stupid question. Only stupid assumptions
You don't have to have it. Depends on what your mechanic has done between services. When the cars roll off the factory floor, the brake fluid is filled to the full line with new brake pads.
As the pads wear over time, the pistons in the calliper moves further and further out to keep the pads in contact with the rotors. This leads to the fluids in the reservoir dropping below the "Max" line but should still be well above the "Min" line. Some mechanics leave it as is (which is what you are supposed to do), other's top it up.
Topping it up creates a problem when you replace the pads. As the new pads will be thicker than your worn pads, you have to push the pistons back to their outer position to accept new pads. This forces brake fluid back up the line into the reservoir, which if topped up, will overfill. And it will leak everywhere (trust me, I learned the hard way
)
Best to have a syringe or something ready to remove the excess fluid when you are pushing on the pistons.
Also, check to see if your brake fluid is currently near the "Max" line as an indication to see if your mechanic has topped up the fluid.
If you decide to remove fluid, only remove what you need to. The last thing you want is for the level dropping below "Min" line, and air getting into the system.
A note regarding the guide / slide bolts holding the calliper onto the car, they only require very little torque to do up. I wouldn't go past 30 Nm of torque. Don't over torque it as the bolt will easily strip.
Bookmarks