2003 Grand AM

[Carjinx]

2003 Grand AM 2.2l ecotec

I bought the car a month ago no problems at all, had the car in the garage for a safety everything was perfect (just needed a peanut bulb for the front headlight) The very next day I lost the brakes. One second there is a full brake the next there is none. Brought the car back to the garage and put her on the ramps and there was brakes on 3 wheels but not the front drivers side. The mechanic said the flex line was collapsed. After bleeding all lines again there is no fluid coming from the front drivers side..

Replaced the flex line same thing no brake on the front. No fluid from bleeding. Left the bleeder open over night and even drove with it open no fluid.

Took off all lines blew them out to make sure there was no blockage all lines are clear. Hooked them all up bled the brakes again and still no front drivers side brake.

Removed the junction box located under the battery blew that out and no brakes anywhere on the car. Opened the bleeders and pumped, the pedal goes to the floor no fluid.

Not sure what the problem could be. Master cylinder was checked and same for the brake booster both are working.

Any ideas??? Kinda stumped and frustrated

Thanks
Samantha

[GTP Dad]

Welcome to AF!!

The mechanic has done quite a bit to diagnose this issue. It is possible that there is air in the master cylinder and in the ABS. Obviously there is a blockage somewhere that is not letting fluid to the front brake. I suggest replacing the master cylinder and seeing what happens. Just because it bench tested good does not mean that it works properly. Also I would have the ABS checked out and possibly replaced. It is odd that there would be fluid in one place and not in another but anything can happen. Finally, have him check the proportioning valve and see if there is a blockage there. If dirt or something got in that it could cause problems as well. Good Luck!

[Carjinx]

Thanks, I will get another master cylinder. Where is the proportioning valve located? I haven't heard of that.

[Tech II]

Proportioning valve affects the rear brakes.....

Leaning more towards the ABS unit rather than the M/C, if you are getting pressure to the RF.....

[Carjinx]

The ABS dash light isn't on so I never would have thought of that. Should the Check Engine light come on with brake problems? Cause that isn't on....

[Tizzymom]

I am the owner of a 2003 grand am and recently have started having trouble with certain things. The darn thing just randomly will not start. I had a loose battery cable which was a stripped bolt but it still is having problems. I had the oil sensor replaced and that was the initial problem. It was leaking oil onto my starter but after it was fixed the mechanic said the starter should be fine but could go out! It will turn over but then not start and then the darn trunk pops and the doors lock! Makes a strange "tick tick tick" sound when I turn it over to try to start after the trunk pops! UGH I am getting very frustrated with this! Please offer some advice PLEASE

[GTP Dad]

Welcome to AF!!

Have the battery checked to see if it is strong enough to turn the car over fully. Then I suggest that you replace the starter solenoid on the starter. It sounds like it is not engaging. It could be that oil has gotten into the wiring and it is not making good connections. This can be corrected by cleaning the wiring with contact cleaner before reinstalling. As for the trunk popping open and the doors locking you either have a short in the electrical system or the body control module is going bad. I hope this helps.

[Carjinx]

Thanks for your help. Changed the junction box that is located under the battery and the same thing happened, a brake one minute then the next time none. Changed the master cylinder and problem solved