I have a jeep liberty 07. I bought it used in a okay condition as it had been in a accident. everything runned great when I first bought it but then one day when I applied the brake the pedal got hard and a noise was heard in the left side. This only happens a couple of times. Sometimes I even go for 2 weeks without having this problem. Just want to know what can be the cause
When ever an accident occurs, or damage outside of the scope of operation, it is crucial that you have someone qualified inspect the vehicle. Normal operation, maintenance, repair experience is not relative in this case as damage can cause too many variables.
If the vehicle has been in an accident it should not be diagnosed as if the part has reached end-of-life.
No one on the internet can give you a proper answer over "Have it looked at by an independent mechanic."
It is not safe, or decent, for us to speculate that repairs were done correctly, nor should we assume that the noises are normal.
Everything could be fine, but at the same time the accident damage and/or the repair could be poor/failing/Improper and highly dangerous.
Please bring the vehicle into a mechanic.
If you don't already know a mechanic, ask around, check reviews, etc... But you need to bring the vehicle in for an inspection by a mechanic that was not involved with the sale.