Chojun

Hey Guys,

Sorry about the 2nd thread but I need some urgent help with this (need to go to work in the morning). I changed out front calipers with legend upgrade and 4 new SS lines. I pulled all the calipers off to paint them.

I had a bit of trouble with the fronts and had them off for a while. I noticed that the brake fluid reservoir ran empty while I had them off. I filled it back up after putting the calipers on and followed the bleeding procedure from the manual.

I've bled all wheels about 2x and don't get any air bubbles out, but the pedal goes down to the floor (with a bit of resistance).

I've noticed that the fluid reservoir goes down a bit when the pedal is depressed, and then fills back up when released. Any ideas? Thanks!

Chojun

Just an update: I thought I'd be brave and see how much braking ability I have in my driveway. It was scary as hell at first because my car wouldn't stop, but after a moment of trial I was able to get my car to at least stop. If I were going downhill I doubt it would be able to stop.

I noticed that the pedal firms up a bit sometimes.

Also the fronts vibrate like crazy when coming to a stop. Could that be a symptom of a lot of air in the system? I put caliper grease on all moving parts and on the backs of the pads where they contact the caliper fingers.

cu2wagon

Air in the system.

Are you doing the old assistant pump, pump, hold, while you bleed? Or are you using a mityvac type bleeder?

I had a bugger of a time doing a brake bleed with the same symptoms you mentioned. Picked up a mityvac at harbor freight and knocked it out, no problem.

Skirmich

^ 2nd that... hella air in the system.. Need to purge it at least 2 more times to be sure..

Also remember about your E-Brake Pedal in those situations!!! It's sole purpose is to stop the car if the hydro brakes fail.

Chojun

Lol thanks guys you were right. I had a feeling I should bleed the system again (using the assistant method all along). I used the recommended FL FR RR RL pattern. I got increasing amounts of air as I moved along until RL, it was like someone popped open a fizzy drink. Lol!

Also, I was a bit careless the first time around bleeding and had poor lighting. I thought when I stopped seeing the big bubbles that I was done. Well the last round I looked closer and there were thousands of micro bubbles coming through.

Also after listening closely I could hear air bubbling around in the master cylinder.

If your reservoir drops when pumping, but then fills back up after you stop, then you know you have air in your system.

Hope it helps!

BTW my e-brakes have done this in the past but do you guys notice that if you put the brake on whilst moving that it makes a kind of shifting bump or clunk noise?

Skirmich

^ That means your e-brake needs attention.. If I fully depress my e-brake while moving I will be end up Tokyo drifting because they will lock up.

Chojun

Okay. Mine lock up as well but they just make a clunk noise when they engage (or if I try to move the car from stopped with them engaged). I had a bit of trouble getting them adjusted. The pads have ~1-2mm on them so I know it's getting time to get the shoes replaced.

This may or may not be because my wife has driven the car with them engaged.

Skirmich

Ohh Yes when they engage at low speed they will make a noise as the pad will physically move, the noise comes from the tension springs.

01tl4tl

they are NOT Emergency brakes! they are Parking brakes!!

When you have brake lines open/removed for replacement or caliper installation,
after inital bleed- where you are now with it finally working=
YOU MUST DO 2 ABS active full stops from 45mph to stopped!!
Accellerate normally and repeat 45mph full abs active to stop

That means find water or gravel and with pedal pushed as if your life depends on it, swerve the wheel back and forth to break traction
The brake pedal will pulsate very rapdily under your foot- stay on it!

Once both stops performed- compare them. Was the pedal firmer 2nd time?
That means you had air trapped in the ABS which is now moved to the regular system and can be bled out at the calipers
Usually ends up at LF but do them all to be sure

Tip! It takes about 1.5 qts to fully flush the brake fluid system, and that should be done once a year!
Once every 2 years MAX between fluid changes!

Even if you think the air is all gone- without this procedure (from factory manual) there may be air hiding in the ABS!!

Chojun

Thanks. I'm waiting for the bedding process to be complete before I do the ABS stops.

I also went through an entire large bottle of brake fluid so I'm pretty sure I got all the old nasty stuff out

SuperGreg

^^^ Yeah absolutely this. I've found gravel works well.

I changed my brake fluid for the first time when my car was about 12 years old. I also rebuilt my calipers and expected the worst - but found no rust. I think I'll flush every 2-3 years from now on, but I think yearly is overkill. YMMV.

SuperGreg

Just find a gravel parking lot and do a few stops with the brake floored, the wear on the disks/pads will be inconsequential.

01tl4tl

on cold brakes the ABS stops wont hurt your new pads and rotors
IF they were hot hot from bedding exercises, that would be a bad plan

IN general I suggest IF adding new lines or calipers- install them first - using old pads.
Perform the 2 abs stops to dislodge air bubbles hiding inside the ABS pump
then install new pads and go bedding!
45mph is the factory repair book speed- guessing so ABS has time to work for a few seconds