Hello all the car in question is honda civic 96 exi with rear drum brakes.the car has developed an issue of soft brake pedal.i have changed master cylinder along with servo.But the actual problem is air in barke system.whenever the bleeding is done on brake system it behaves perfect.But after 2 or days the pedal starts becoming soft.There is alaways rear right wheel which has air in it.all other wheels throw oil with pressure while bleeding.The master cylinder does hold pressure at engine off position.The brake system is sucking air from somewhere Because bleeding is done several times,any trapped shoould have gone by now.Done bleeding on saturday,it becomes perfect for first few kms,on my return journey today from Gujrawala there was none braking.used engine compression,puming of pedal and hand brake to reach lahore while driving at 60 km/hr.Again done bleeding 2 hours before and it becomes perfect again.As usual it was rear right wheel,which was bleeded.What is the issue,sick of doing bleeding again n again.
Any suggestions and tips are welcome.specially zulfiqar plz contribute here.