Brakes have gone dodgy on my 09 Rubicon

[Johnboy]

Im using DOT 4 but it says compatible with 3 or 4, i'll check the oe specs maybe a new master and a flushout with DOT 3 is in order

[st_za]

It sounds more likely that you have a problem with the brake booster or a vacuum problem. I would start by checking that the vacuum pump is working. It is usually behind the front bumper or relocated to the lower passenger side front.

[Johnboy]

Brakes sorted, after a bit of rooting around and bleeding i diagnosed that the master cylinder was faulty the front brakes were working but the rear section of the master was bypassing and not building pressure to the rear brakes. A new master cylinder from SBR and a stab on the brakes nearly puts you through the windscreen!!! So I'm thinking that the master must have been marginal for several years and the excessive pressure applied hanging of the side of the hill must have finished it off.