Jump to content

Missing Brake Fluid


Recommended Posts

I have had both sides of my brake master cylinder go dry twice. It takes a very long time to go down and I have not found a leak. All four corners are dry and I have followed the lines and no leaks. Can it drain back into the booster? I have seen this happen on older cars but only on the back side of the master cylinder not both sides.

 

Thanks, Steve

Link to comment
Share on other sites

It can drain back into the booster, both seals bad in MC but that is very improbable. Pull the vacuum line from the booster and see if there is any trace of fluid. Recheck your wheel cylinders. A leak that slow would get covered up with fresh brake dust and not show as a fresh leak.

Link to comment
Share on other sites

It can drain back into the booster, both seals bad in MC but that is very improbable. Pull the vacuum line from the booster and see if there is any trace of fluid. Recheck your wheel cylinders. A leak that slow would get covered up with fresh brake dust and not show as a fresh leak.

Would the rear slave cylinders allow both sides of the master cylinder drain?

Link to comment
Share on other sites

It can drain back into the booster, both seals bad in MC but that is very improbable. Pull the vacuum line from the booster and see if there is any trace of fluid. Recheck your wheel cylinders. A leak that slow would get covered up with fresh brake dust and not show as a fresh leak.

Would the rear slave cylinders allow both sides of the master cylinder drain?

No. There is a seal between the two master cylinders. Both seals would have to go bad. You will notice one of the master cylinders is larger than the other. That one is for the rear brakes. The smaller reservoir is for the front brakes. That is, if you have disc brakes in front and drum in back. Normal shoe wear will lower the fluid level. Not empty the reservoir.

Link to comment
Share on other sites

  • 4 weeks later...
It can drain back into the booster, both seals bad in MC but that is very improbable. Pull the vacuum line from the booster and see if there is any trace of fluid. Recheck your wheel cylinders. A leak that slow would get covered up with fresh brake dust and not show as a fresh leak.

Would the rear slave cylinders allow both sides of the master cylinder drain?

No. There is a seal between the two master cylinders. Both seals would have to go bad. You will notice one of the master cylinders is larger than the other. That one is for the rear brakes. The smaller reservoir is for the front brakes. That is, if you have disc brakes in front and drum in back. Normal shoe wear will lower the fluid level. Not empty the reservoir.

 

Backwards. Larger rez is front because the disc brakes require more fluid due to wear and tear.

 

I've had the master throw fluid over the "wall" between front and back and empty both.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...