F/51 LRS

thats what I thought, too. In my new line zeal I didn't pay enough attention.

Thanks, looks like I'll pick up another line...and bleed the brakes again. D'oh.

apanossi

Make sure you're using a line bender. Even the cheapo ones from Autozone will work as long as you're patient.

F/51 LRS

I started the car today after finishing this up last weekend and had a soft pedal as well as ABS lights and PDAS light on the dash.

Figured there's air in the lines somewhere, I re-bled the brake lines and was about to do the accumulator etc. in the frunk when my motive cap broke.

I thought I would see what's what without doing the frunk bleeds, but still had the ABS/PDAS lights, and if I pumped the brakes I would get the brake warning light/buzzer.

I ordered up a new cap for the Motive and will finish the frunk bleeds when it arrives.

Do the issues I am seeing seem like they're a result of air in the system up front?

Thanks again for everyone's help.

Goughary

It's likely Air - yes.

Hope you ordered the aluminum cap for the motive.

apanossi

+1 air

F/51 LRS

Since I opened up the system by putting new lines on do I need to also bleed the diff locks?

Or am I fine doing the brakes, the bomb, and the dual solenoid valve block?

I don't have access to a hammer, so that's the main reason I haven't bled the locks.

apanossi

You probably should if it hasn't been done before. If you were careful and clamped off the open ends so fluid didn't run out (keeping the brake depressed when opening brake lines accomplishes this), then you won't necessarily introduce too much air into the system so that you can only bleed the one corner of the car without having to bleed the whole system. I have a PDT hammer which does everything the Bosch hammer does at a fraction of the price.

F/51 LRS

Unfortunately fluid did leak out while I was changing the lines.

My m3 is being sold tomorrow so the 911 will be my sole mode of transportation.

With that being said, is my only option to bleed the locks?

I've read that if you cycle the ignition and crack open the bleeders slightly (albeit many times) that you can bleed them that way without having a hammer. Is that correct? If so, that may have to be the temporary work around.

F/51 LRS

Alright, yet another development. Started the car, awd/abs/brake lights were on.
Then they went away.
They stay off unless I pay mp the brakes 5-6 times, this is while the car is running.
As soon as I stop pumping the brakes the lights go off.

There is pressure in the pedal, and if I just push it without pumping, no lights.

F/51 LRS

Here's a video of what's going on.

I just talked to John Walker here in Seattle, his recommendation was to "Get it out there and drive it. There's nothing I can think that would be damaged there."

Thoughts? It makes sense to me, but I don't want to have a potentially very expensive fix on my hands.

Goughary

You should be ok to drive without breaking anything. Question is whether the system is properly pressurizing and if it's not, you could find yourself losing your brake pedal - well, you would still likely have brakes, but when the system is depressurized, the pedal force needed is way higher to stop the car. So in a road situation if you weren't ready for that you could find yourself in trouble.

That said. If it were me, yes I'd drive the car. Sometimes feeling thjngs out gives you ideas for what to look at. What it sounds like to me, is you have Air in the system. And honestly, it sounds like your pressure bomb is blown. There is a delicate bladder in there. And even if you just once, let the pressure out too fast when you are bleeding the car, you can damage that bladder. Always go slow when you are bleeding that unit.

As to the diff locks. If you don't have a pdt or hammer, buy two stainless steel speed bleeders. M6x1, and install those on the diff locks. Crack one open, get in the car and work the locks for a half hour each or so, using the controller in the center console...takes longer but does the job. No hammer necessary.

Anyway . Next up. With the car off. Pump your brake pedal till it gets dead hard . This is when you have released all pressure from the system. Turn the car on and listen to the pressurizer. It should take 50-60 seconds to pressurize from zero. If you start getting waaaaay over that, your bomb is gone.

Drive the car a bit. Re-bleed. Then do this other stuff...likelihood is just air in the lines anyway.

Spyerx

^^^ Agreed on air. When doing mine (I had the full system apart, granted not a C4 so easier) with new M/C, new brakes, lines it took a couple go arounds to really get all the air out.

FeralComprehension

(emphasis added)

Agree with everything the wise G said but the point above bears repeating. The input force required once you lose pressure is easily 10x what it took previously. Also, there's no real warning, no gradual degradation; your brakes work normally, then they don't.