Volvo 2008 C70 185,000 miles automatic
i got my front rotors and pads replaced. They did not bleed the lines.
a few weeks later, my brakes failed. after turning the car off (after i bumped the person in front of me at a red light, no damage!) and restarted the car, my brakes worked. took it back to mechanic, he said they don't have to bleed lines anymore because of some reason, i don't remember. He checked for leaks, no leaks, all looked good. He drove it a few days to recreate failing brakes, couldn't do it. we decided to change the master cylinder as a precaution. ok. so my question, is did he indeed, need to bleed the lines when he replaced rotors and pads? This is a concern for me driving, because he's left it open ended....don't know if this will fix brake issue, replacing master cylinder and now he has to bleed the lines. this is new mechanic for me, he comes highly recommended, i know he doesn't want to tell me it's all fine, when he couldn't fail the brakes, but i am not feeling great about driving again. should i be after work is done?
he said they don't have to bleed lines anymore because of some reason
You don't have to bleed the brakes unless the hydraulic system is opened up, so unless they replaced calipers or brake lines there was no need to do that.
did he indeed, need to bleed the lines when he replaced rotors and pads?
no. What for?
because somehow air got in line?
if air got in then bleeding wouldn't help. You would need to replace whatever is leaking.
More likely you had an ABS malfunction , like wheel speed sensor dropping out.
because somehow air got in line? i am guessing that air would have gotten in all my lines? i don't know at all, i do not have a lot of experience about cars and all that can go wrong.
why would my brakes fail then work again? many reasons? would replacing master cylinder allow me confidence when driving?