Hey guys need some help

[DerpTheGod]

My front passenger brake locked up while driving on the highway. My ABS light has always been on but just recently my E Brake light had been flashing. I was able to drive the car for about 5 minutes, after that the front passenger brake starts building pressure and not releasing when I let go of the brake pedal. Then it just locks up. (does that make sense) I've read it was due to low fluid but my fluid levels look fine. My brake pads and rotors looked fine when I took them apart. I've also read that it could be do to old damaged/old brake lines so I switched out the brake lines to stainless steel and nothing has changed. Now whenever I try to bleed the front passenger brake line no fluid comes out at all. All the other lines I can get fluid out. What can be causing this? Any help is appreciated

[moyenecorniche]

Sounds like you have an air bubble trapped in the lines and / or you have debris obstructing flow. The latter could of been from debris in your brake fluid reservoir. With old brake lines you need to flush out the system before you add new fluid after purging the old. My guess is from corrosion somewhere in the system debris particles clogged your lines. If you brake warning was on why did you wait so long to attend to it. You'll need toopen things up again and flush out whatever is obstructing. Plus if you had water in the system then with the cold it turned to ic e and definitely would plug things up.

You should diagnose what is causing the ABS warning to be on. That could also be the culprit in addition to the above.

[HearMeSpool]

Sounds like air in the system. Try bleeding the master cylinder.

[DerpTheGod]

I'm using a Mityvac - Vacuum Pump to bleed the brakes. I pump to 15psi, open the bleeder and fluid comes out. When I get to the front passenger and I pump to 15psi, open the bleeder the psi drops to 0.

[Thumper3]

You should diagnose what is causing the ABS warning to be on. That could also be the culprit in addition to the above.

This.

it is really hard to diagnosis other issues when there is a known issue not resolved. Proper troubleshooting means fixing everything you know is broken (eliminate possible causes) and then track down issues.

It is unlikely air would cause absolutely no fluid to flow from the line, especially using a powered bleeder. The entire purpose of bleeding is to remove air.

It sounds to me like there is a blockage, either debris as suggested or more likely based on a warning light, a failure in the ABS unit. Something getting stuck closed would cut the system to shut down flow to line on that wheel, ect.

Get the ABS light scanned, find out the trouble code and what's wrong, then see if this issue resolves.

[moyenecorniche]

Remember that our systems are based on an X pattern so that if something is wrong ( as you have ) you still have opposing front and rear to stop you. Granted you already have that unintentionally but the point is the problem could be at the opposite end. But diagnose the ABS issue first, get your car hooked up to a laptop and find what codes are showing what.

That is first... Otherwise you'll be chasing your tail..

[DerpTheGod]

I will try to get it to a mechanic that can hook it up and tell me what why the ABS light is on. Thanks everyone

[chaos2984]

Well it can be 2 things. Your rubber line from the frame to the brake caliper could of pinched closed. That can cause your issue. Or your abs module when goofy and it pushed the valve out. But when you opened the bleeder the first time on that caliper that locked up did any fluid come out and did the caliper release? Or is the caliper still locked up? Are you just using a vacuum bleeder or a pressure bleeder. You might want to undo the line that connects to the frame hard line and see if you can get fluid out there. If you can get fluid out there just by gravity or by pumping the pedal then your issue is with the rubber line that goes to the caliper from the frame hard line. If you cant get fluid out there you need to go back to the ABS module and see if you get fluid coming out of the outlet port of the abs module for that wheel. If you do then you have something in your hard line that needs flushed out. If not then you have an issues with the abs valving.

[LightningLou]

I'm going to go out on a limb here and say you should replace the ABS pump assy. under the hood. Luckily, that is probably the easiest thing you can change on these cars since it is right on top. Had my front drivers caliper completely lock up on my daily which is a Contour SVT and I tried to vacuum bleed and nothing would come out until I disconnected the line at the pump and found that there was no clog. Picked up another pump assy. for $40 from a junkyard and bled the lines again and all calipers and ABS work perfect again. That pump however was a royal pain in the ass to change on that car as it is buried under the master cylinder and brake booster, so both needed to be removed. Wish it was the S4 that had the issue lol. This should also get rid of your ABS light which is probably due to the pump being faulty anyhow.

[DerpTheGod]

@chaos2984 I have changed all my lines to stainless steel. The first time I open the bleeder fluid did come out and the caliper did release. Now as soon as I open the vacuum bleeder the PSI drops to 0, as all other 3 stay at 15PSI.

@lightninLou If everything else fails that will be my next step