1998 Dodge Caravan Air in RR brake line

RATHOMAS

MEMBER
1998 DODGE CARAVAN
6 CYL
FWD
AUTOMATIC
110,000 MILES

The brake pedal went to the floor. Would not pump up. No fluid was leaking anywhere. Decided to replace the master cyl. Did that, bled the brakes and all worked well. Thought the problem was solved. Two days later No pedal! Bled the brakes again and got air from rr. Figured just didn't get all the air the first time. Drove it a couple of days and it did it again! Maybe a defective master cyl. Replaced with a secound new one. Good brakes again. Two days later. Air. In the RR again! No fluid leaks anywhere but still getting air in the right rear! Had another shop bleed the system and two days later. Air again in the RR! Still no leaks. Where is the air coming from?

1 Reply

GWOLKING

MEMBER
10 POSTS

When the brakes went dead, was the fluid reservoir actually empty? If not, my guess is that air is getting in through the right rear wheel cylinder. It's possible for a seal to hold under compression when you're applying the brakes but leak and suck air in when you release them. Once you get enough air into the system, everything stops working.

For a test, try driving a short distance and using the brakes a few times, then bleed the right rear again. If you get air *immediately*, it's probably leaking in from the cylinder. If you get clean fluid at first, *then* air, the air must be getting in somewhere farther up the system (bad flex hose, maybe?).