Quote Originally Posted by jeffishot
mga bro, napansin ko lang na every time that i inspect my car every morning, i noticed that back up reservoir for the radiator is always half empty. this forces me to re fill it every morning before i drive out. i am sure wala naman leak yung radiator or problem yung cylinder head ko.

the only peculiar thing that i noticed is that the cap for the back up reservoir is popped out everytime i inpsect my engine as if meron pressure. may duda akong dito tumatapon ang tubig. can anyone help me on this?
Radiator Cap is set to lift at around 15 PSIG. If the pressure is greater, the cap will release some of the pressure to your reservoir, thats why never overfill your reservoir, leave it half empty for radiator coolant expansion. Anyway, this is a good site to check: http://auto.howstuffworks.com/cooling-system7.htm