Clio 182 ff
as the title suggests I've been having a issue with the brakes on my clio 182ff recently. a while ago whilst in heavy traffic i went to press the brakes to be greeted with a really firm pedal, with a few inches of travel and a feeling as if the pedal was being blocked, after a while the pedal went back to normal. After reading up on here for possible causes i changed the vacuum pipe which i thought solved the issue. yesterday whilst it was raining i came back to my car and went to pull off and the back end dipped down as if the rear brakes were sticking, i pulled the handbrake up and down a few times which seemed to release it. today again whilst raining in traffic i went to touch the brakes and the same issue again, pedal travel was reduced and firm again. i have had a brake servo fail on my van and the brakes needed both feet to stop but with this i can still stop well so i feel it cant be the servo. to add i have had the front brakes cleaned up in full with the slide pins greased ect. its just passed its mot with no issues at all. could it be the rear brakes binding on with the rain or even the handbrake cable sticking on that is causing the firm feeling. all other times the brakes feel great and really powerful, emergency stops are powerful with no issues either ? any ideas guys thanks