Brake bleeding, need simplfied

[Seriousless]

Got another A4 b6 and noticed the brake light was on. Checked the sensors and saw the front one was unclipped and ripped out of the pad. The guy who sold it said it has all new brakes. Naturally wanting to see how bad I am at buying stuff I decided to check everything and realized every pad was a different brand along with the calipers. The rear were non existent and was halfway through the metal, front were just done and sensors ripped because they were never plugged in. Removing the pads I realized the one front and one rear caliper had bad pistons so in the end because parts are cheap here for some reason I did brembo pads and new Audi original calipers all around. Fast forward a few hours in my apartment parking lot and Im now bleeding the brakes. Now not being familiar german cars I did the wrong seqience and started at the rear. I know the sequence now. My concern is I have read I need to have the engine running? Im not using a pressure bleeder but the 2 person pump pump hold method. When I originally bled the brakes in the wrong sequence i had no air and solid fluid and got a good stiff pedal. But when i started the car to go for a test drive the pedal dropped bad and wouldnt pump hard but would still pump. I could stop if I wanted to but it is definitely not a good pedal feel or safe for main roads. I also read something about using vcds to reset the ABS? I think I have vcds but havent used it yet and am not familiar with it at all. Also read something about needing to bleed the clutch now too? When I went for the test drive clutch was fine and pedal was good.

I know this stuff has been posted before but they are old threads and stuff changes, just trying to get a clear definitive answers.

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[Cybersombosis]

When you bled your brakes, did you make sure that the reservoir was full? Did any air get introduced to the system?

[Seriousless]

Cap off resevoir full and topped off each bleed with fresh fluid, no air was introduced, even when the caliper was swapped the hose was clamped before the banjo bolt was removed.

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[Cybersombosis]

Did you go ahead and bleed them again in the correct sequence? I suspect there is air in the system especially if you had to open up each corner. Please walk us through your technique step by step. For example.

1. Guy in car pumps on the pedal and holds.
2. Guy at the brakes opens the bleeder and watches fluid push out while guy in car’s foot falls to the floor.
3. Guy at brake closes the bleeder.
4. Repeat process a few more times.

[Seriousless]

Yes exactly what happened in addition after i had solid fluid and closed the bleeder I would have my pedal pusher test the pedal for stiffness, bled each side until there was solid fluid and a stiff pedal. Then would proceed to the next. I only figured out the sequence after my failed test drive and ive run out of time tonight. Tommorow morning Im going to redo everything in the correct sequence. Im assuming that this arent all bad because I did have enough pressure to stop the car, just tons of travel in the pedal so im hoping the correct sequence will remedy that. I just wanted to get prepared for tommorow and see If i was missing something that is special with Audis like engine running or plugging in a computer to do a brake job. I do have an Audi mechanic somewhat close but its half hour drive on 120km highway, would really prefer not to do that unless I absolutely have to.


* edit

So after watching some videos Im seeing that everyone is doing the sequence I originally did starting on rear passenger, rear drivers side, front passenger and finally front drivers side. From what ive read though its opposite. Any clarofication on this?
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[Turbo510]

Now not being familiar german cars I did the wrong seqience and started at the rear. I know the sequence now.

You mentioned a "correct" sequence, but never said what you understand that to be. The correct sequence is to start at the furthest caliper from the master cylinder (right rear) and work to the closest (left front). The engine does not need to be running, but VAG-COM aka VCDS can be used to run the ABS pump in the case that it contains air- however I've never done that ABS procedure.

I personally use a one-person (me) method: instead of simply plugging a hose onto each bleeder nipple, which requires the second person to open and close it, I have a small check-valve in line with the hose, which allows me to open the bleeder, then get in the car and pump as many times as I want pretty quickly. Just keep an eye on the fluid level, perhaps ignition ON to check for the brake fluid warning. If you do have a helper, they can tell you when there are no more bubbles and the fluid is clear.

[Seriousless]

Actually edited my most recent reply about the sequence because ive been doing some more digging so that says the sequence I did. RR,RL,FR,FL.

I found an old post from 2006 i think where someone posted the instructions from an Audi manual saying to do it in the reverse order I did with the engine running, hence my confusion about the sequence being wrong. If my first sequence was correct I may just try and redo it all the same in the morning and flush more fluid through it all. They are new calipers so they may need to be cycled more maybe that used old ones.

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[EuroxS4]

I would not be bleeding brakes with the engine running. I would also note clamp off a brake line when changing calipers. Definitely air in the system. What is the orientation of the bleeder screws on the rear calipers?

[Halvis]

just keep bleeding and keep an eye on the level in the reservoir.

[Seriousless]

Lines were clamped off while swapping. Bleed screws on rears are just up a bit from middle facing towards the rear, fronts are at the top facing towards rear., these arent aftermarket they are original audi brakes calipers.

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[Seriousless]

I would not be bleeding brakes with the engine running. I would also note clamp off a brake line when changing calipers. Definitely air in the system. What is the orientation of the bleeder screws on the rear calipers?

Lines were clamped off while swapping. Bleed screws on rears are just up a bit from middle facing towards the rear, fronts are at the top facing towards rear., these arent aftermarket they are original audi brakes calipers.


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[Puddin Tane]

Lines were clamped off while swapping.

This language suggests you crushed the brake hoses flat to stop fluid from flowing. Did you? I hope you meant plugged or capped.

[Seriousless]

This language suggests you crushed the brake hoses flat to stop fluid from flowing. Did you? I hope you meant plugged or capped.

No they were not crushed flat the language suggests they were clamped. With only enough force according to the viscosity of the fluid., I use the same clamp i use at work that is designed to clamp off hydraulic lines of the same diameter without damaging them. In addition even after "crushing" the lines the fluid flow was consistent and uninterrupted. The lines are fine.

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[EuroxS4]

Ok but bleeder screws are facing up towards the sky correct not facing down towards the ground?

[Seriousless]

Ok but bleeder screws are facing up towards the sky correct not facing down towards the ground?

Yes the calipers are not on backwards.

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[Kevin C]

Personal experience is that bleeding sequence helps but is not the end all, especially if you do each corner twice. What I have found is that fresh pads and calipers develop a better feel once you get them seated. If your not getting a brake light and it will stop but only has a low pedal try driving it a bit to burnish the pads. Using the e brake might help. I have had this happen on every pad and caliper swap I have done on my Audi. That included rebuilt stock calipers, reman calipers that I have bought and a pad swap on used calipers. This was part of a continual upgrade from stock 1.8T to B6 3.0, B7 A4 and finally S4 brakes. Most times they were calipers that I rebuilt myself and for the S4 front brakes I bought remans. The low pedal was kind of disconcerting but it came back pretty quickly I seems like the fresh pad faces have a bit of give and once burnished to the rotor that extra travel goes away.

When bleeding a good sign is that the pedal drops as you open the bleeder screw. If your are getting that on both sides after bleeding you should be good. Even the one time I let my reservoir run dry all I needed to do was a standard bleeding.

[Seriousless]

Personal experience is that bleeding sequence helps but is not the end all, especially if you do each corner twice. What I have found is that fresh pads and calipers develop a better feel once you get them seated. If your not getting a brake light and it will stop but only has a low pedal try driving it a bit to burnish the pads. Using the e brake might help. I have had this happen on every pad and caliper swap I have done on my Audi. That included rebuilt stock calipers, reman calipers that I have bought and a pad swap on used calipers. This was part of a continual upgrade from stock 1.8T to B6 3.0, B7 A4 and finally S4 brakes. Most times they were calipers that I rebuilt myself and for the S4 front brakes I bought remans. The low pedal was kind of disconcerting but it came back pretty quickly I seems like the fresh pad faces have a bit of give and once burnished to the rotor that extra travel goes away.

When bleeding a good sign is that the pedal drops as you open the bleeder screw. If your are getting that on both sides after bleeding you should be good. Even the one time I let my reservoir run dry all I needed to do was a standard bleeding.

Really appreciate this advice and thats exactly what I did. I got up this morning thinking, "well I have new pads and new calipers. I also havent bedded them yet so nothing has found its home." Re bled everything in the same sequence and even during the second bleeding noticed a difference in the pedal got out a bit more air that had settled (mostly micro bubbles). I would say I do officially have brakes now, although a bit squishy at the bottom of the pedal theres is good pressure throughtout the whole pedal now. Ill simply rebleed after a 100km or so and they have been bedded. You can only go about 30km an hour in my city and my work is only a km away so its simple enough to keep an eye on them and wont be any hard driving on them for awhile. I also read somewhere that the Brembo pads Im using managa heat really well and take a little longer than normal to bed.

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[BumblebVR6]

Personal experience is that bleeding sequence helps but is not the end all, especially if you do each corner twice. What I have found is that fresh pads and calipers develop a better feel once you get them seated. If your not getting a brake light and it will stop but only has a low pedal try driving it a bit to burnish the pads. Using the e brake might help. I have had this happen on every pad and caliper swap I have done on my Audi. That included rebuilt stock calipers, reman calipers that I have bought and a pad swap on used calipers. This was part of a continual upgrade from stock 1.8T to B6 3.0, B7 A4 and finally S4 brakes. Most times they were calipers that I rebuilt myself and for the S4 front brakes I bought remans. The low pedal was kind of disconcerting but it came back pretty quickly I seems like the fresh pad faces have a bit of give and once burnished to the rotor that extra travel goes away.

When bleeding a good sign is that the pedal drops as you open the bleeder screw. If your are getting that on both sides after bleeding you should be good. Even the one time I let my reservoir run dry all I needed to do was a standard bleeding.

This has been my same experience on numerous occasions. One thing for sure is that if the level in the reservoir drops and the system empties, the two man bleed method by actually pumping the pedal is necessary, power bleeder such as the Motive won't work from my experience.

[EuroxS4]

Personal experience is that bleeding sequence helps but is not the end all, especially if you do each corner twice. What I have found is that fresh pads and calipers develop a better feel once you get them seated. If your not getting a brake light and it will stop but only has a low pedal try driving it a bit to burnish the pads. Using the e brake might help. I have had this happen on every pad and caliper swap I have done on my Audi. That included rebuilt stock calipers, reman calipers that I have bought and a pad swap on used calipers. This was part of a continual upgrade from stock 1.8T to B6 3.0, B7 A4 and finally S4 brakes. Most times they were calipers that I rebuilt myself and for the S4 front brakes I bought remans. The low pedal was kind of disconcerting but it came back pretty quickly I seems like the fresh pad faces have a bit of give and once burnished to the rotor that extra travel goes away.

When bleeding a good sign is that the pedal drops as you open the bleeder screw. If your are getting that on both sides after bleeding you should be good. Even the one time I let my reservoir run dry all I needed to do was a standard bleeding.

It was my understanding that this is common knowledge, but yes you have to bed the pads in well and pedal feel will improve.

[Turbo510]

Normally, brake bleeding is a pretty standard affair. As I mentioned, I prefer to use the brake pedal, since the sudden surge of fluid is bound to stir-up and help purge any debris and contaminated fluid from the calipers. My check-valve approach drastically speeds up the process, so all that your helper needs to do is pump the pedal, while you watch for the fluid to become clear and bubble-free.

That being said, I did a first brake fluid change on my 1986 Mercedes-Benz 560SL, and it did not go as planned. After pumping old fluid from the rear calipers, after awhile all that came out was air - and I could look into the filler and see that the reservoir was nearly full. I couldn't figure out where air was coming from, and why the reservoir level didn't appear to drop. I finally learned that these reservoirs have a high partition between the front and rear sections, and the front has to be over-filled to get fluid into the rear section. The filler is over the front section, plus a smudgy film on the inside surface kept me from noticing the apparently full rear reservoir was actually empty.

[old guy]

I just bleed my brakes today. 1.5 hours start to finish. Car up on ramps and floor jacks to lift the rear.

Motive pressure bleeder set to 20 psi. Bled LF, RF, LR, RR, clutch slave, as per Audi service manual.

Done. No issues.

Edit: To bleed the slave I use a wooden dowel rod between the front seat and the clutch pedal. Push the seat forward enough to depress the clutch ~2". Without this step it is hard to get the fluid flowing through the clutch master cylinder.

[MoRbiD]

I just bleed my brakes today. 1.5 hours start to finish. Car up on ramps and floor jacks to lift the rear.

Motive pressure bleeder set to 20 psi. Bled LF, RF, LR, RR, clutch slave, as per Audi service manual.

Done. No issues.

Edit: To bleed the slave I use a wooden dowel rod between the front seat and the clutch pedal. Push the seat forward enough to depress the clutch ~2". Without this step it is hard to get the fluid flowing through the clutch master cylinder.

^^^ This ^^^^
I've always used a Speedi-Bleeder but still followed that same order. I don't think you can bleed the system on these cars w/o pressure.

[Turbo510]

I don't think you can bleed the system on these cars w/o pressure.

There has to be pressure, and pressure can result from gravity, pressurized air, or the master cylinder. I've always used the MC as previously mentioned.