Hi there -  so i was manually bleeding the brakes on my 2014 Superb Greenline 3 and at one point between a troublesome bleed nipple and communication problems with a friend, I let the brake fluid get quite low in the reservoir. Probably a little below minimum. My quesion is, how low does the tank need to be before air can get into the master cylinder? Looking at diagrams, the feed to the master cylinder is right at the very base of the reservoir with the clutch feed well up above (!?!?!) The minimum mark. I dont *think* the brakes feel spongy but i just want my mind at rest.

 

Many thanks

Shaun

15 minutes ago, Shaunieboy said:

Hi there -  so i was manually bleeding the brakes on my 2014 Superb Greenline 3 and at one point between a troublesome bleed nipple and communication problems with a friend, I let the brake fluid get quite low in the reservoir. Probably a little below minimum. My quesion is, how low does the tank need to be before air can get into the master cylinder? Looking at diagrams, the feed to the master cylinder is right at the very base of the reservoir with the clutch feed well up above (!?!?!) The minimum mark. I dont *think* the brakes feel spongy but i just want my mind at rest.

 

Many thanks

Shaun

As long as there is fluid showing above the bottom of the whole reservoir, air can't get into the system. When you stated that it just dropped a bit below the minimum mark, you have no problem at all. If you ever get air into your braking system, you will find you have to pump the brake pedal to get a normal firm pedal back again.

 

@Shaunieboy - Best practice would be to never let the fluid level drop below the "min" mark but that's there to ensure that the reservoir never goes dry under emergency braking, so as @roaddetective says you should be ok.

7 hours ago, KenONeill said:

@Shaunieboy - Best practice would be to never let the fluid level drop below the "min" mark but that's there to ensure that the reservoir never goes dry under emergency braking, so as @roaddetective says you should be ok.

I appreciate the responses, thank you @KenONeill @roaddetective . My mind is now at rest.