, recently I noticed a slight hissing sound coming from the engine bay after I switch off my Hilux. After some looking I noticed my master cylinder was leaking and the hissing was coming from there. I've managed to find a replacement master cylinder but I'm not sure if I need to replace the booster too. According Google it's just the gasket between the booster and master cylinder that has given way, I'm guessing due to the brake fluid leak. Causing the hissing. But I'm not sure, has anyone experienced this? The booster seems to be working fine. Brake pedal goes down after the engine is turned on. Any advice is welcome!On another forum i read that the gasket does not make a complete seal, and the master cylinder has a drain groove which needs to be kept clear. Is it normal for the booster output pushrod to not be fully sealed, as thats where the hissing comes from.
