[ferocity02]

I just changed the brake pads and flushed the system using the Motiv method of pressuring the reservoir. It never went empty, not even close. But now the brake pedal is much softer than before. It stops fine but takes like 50-100% more travel.

So tonight I tried bleeding with INPA and it feels the same. I did get a lot of nasty fluid out though.

So the next step is to either try bleeding for a third time, or let the dealer have a go.

Has anyone had the dealer bleed/flush their brakes?
How much did it cost?
Was the brake pedal firmer after?

[1QuikWS6]

I have my brakes flushed every (2) yrs at dealer - pedal feels the same before vs after. Cost at my dealer is $120

[Efthreeoh]

I use the Motive power bleeder and it works perfectly. Did you have fluid in the power bleeder? If not and you just used air pressure on the brake reservoir then that is not the proper way to use the Motive power bleeder. Also did you use more than 18 PSI of pressure. Motive says to stay around 18 PSI. Did you bleed into a container with the tube immersed in fluid to prevent air from entering back into the calipers?

If none of that works, go the old fashion route and have an assistant pump the brake pedal while you control the bleed screw at the caliper. Follow the correct order of right rear, left rear, right front, then lastly, left front.

[ferocity02]

Originally Posted by Efthreeoh

I use the Motive power bleeder and it works perfectly. Did you have fluid in the power bleeder? If not and you just used air pressure on the brake reservoir then that is not the proper way to use the Motive power bleeder. Also did you use more than 18 PSI of pressure. Motive says to stay around 18 PSI. Did you bleed into a container with the tube immersed in fluid to prevent air from entering back into the calipers?

If none of that works, go the old fashion route and have an assistant pump the brake pedal while you control the bleed screw at the caliper. Follow the correct order of right rear, left rear, right front, then lastly, left front.

I just pressurized the reservoir with a small air compressor, never got above 20psi. There is no need for the Motiv bottle, it's only function is to keep the reservoir full of fluid. When the reservoir got low I'd close the bleeder, release pressure, open it up and top it off, then continue. It never got below 1/3 full. Nothing ever got sucked back into the calipers, that's the point of the pressurizing the reservoir.

Also, the pressure recommended by Motiv is just a standard value. The Bentley manual suggests 29psi (2 bar).

[John 070]

I used the motive without fluid, and it was fine. I got the tip from the Porsche forum, to avoid cleanup. I would try it again, starting from the beginning. Air must have been introduced somewhere, maybe at one point, not having fluid in the motive, the level just went too low. No biggie, try again imho....

Up until this year, the dealer always flushed my brakes. I dunno if this can be truly considered a bleed, I suppose so, but since there is no issue in the first place, I don't know what method they use to determine they got all the old fluid out at each caliper. And they would not touch the DSC Hydro and do an ABL bleed under the normal 2 yr. flush....

ps when you say you bled with INPA, my understanding is that's the ABL bleed. It's to get air out of the ABS pump, and is in addition to a normal bleed by foot or motive. So my understanding is that ABL bleed is not enough, in itself. And actually, it's not needed unless something got removed and reinstalled...

[avocet]

is the pedal soft and firms up when pumped? or does it feel firm and just has more travel all the time even after pumping?

[ferocity02]

Originally Posted by John 070

I used the motive without fluid, and it was fine. I got the tip from the Porsche forum, to avoid cleanup. I would try it again, starting from the beginning. Air must have been introduced somewhere, maybe at one point, not having fluid in the motive, the level just went too low. No biggie, try again imho....

Up until this year, the dealer always flushed my brakes. I dunno if this can be truly considered a bleed, I suppose so, but since there is no issue in the first place, I don't know what method they use to determine they got all the old fluid out at each caliper. And they would not touch the DSC Hydro and do an ABL bleed under the normal 2 yr. flush....

ps when you say you bled with INPA, my understanding is that's the ABL bleed. It's to get air out of the ABS pump, and is in addition to a normal bleed by foot or motive. So my understanding is that ABL bleed is not enough, in itself. And actually, it's not needed unless something got removed and reinstalled...

The INPA bleed is meant for the DSC, yes. However, if I somehow sucked air into the reservoir then it probably got into the DSC unit as well. The INPA DSC bleed also pumps a ton of fluid through the system, so seems to be meant to bleed the entire system too. This makes sense, because if you get air out of the DSC unit it just ends up in the lines.

I got more fluid out of the system with the INPA bleed than I did with the Motiv method and waiting until the fluid comes out clean.

[Hyper_545i]

OP,

Did you install OEM Pads or Ceramics? I've heard just going to a different pad compound could net the same results. Also, did you bed the new pads in? I've heard you should bed the new pads and then flush the brake fluid.

[ferocity02]

Originally Posted by Hyper_545i

OP,

Did you install OEM Pads or Ceramics? I've heard just going to a different pad compound could net the same results. Also, did you bed the new pads in? I've heard you should bed the new pads and then flush the brake fluid.

I replaced the pads with the same ones that were on there, Akebono. I did not bed them, the manufacturer says not to, rather they say be gentle on the brakes for 500 miles.

Regardless, the pads should not affect the firmness of the pedal. I can physically push the pedal much further down now than I could before, even when stopped.

[Efthreeoh]

Originally Posted by ferocity02

I just pressurized the reservoir with a small air compressor, mevet got above 20psi. There is no need for the Motiv bottle, it's only function is to keep the reservoir full of fluid. When the reservoir got low I'd close the bleeder, release pressure, open it up and top it off, then continue. It never got below 1/3 full. Nothing even got sucked back into the calipers, that's the point of the pressurizing the reservoir.

Sounds like to me you got air in the system somewhere. Since I really can't figure out the procedure you used to bleed the system I'm not going to speculate. But I've been bleeding brakes on BMWs for nearly 30 years and just recently in the past 2 years have been using a Motive power bleeder. The old-timer's method of having someone pump the pedal while the other person opens and closes the bleed screw (dumping the fluid into a catch can with the hose immersed in fluid) will get any air out of the system. As the pedal is pushed, open the bleed screw and let the pedal slowly go to the bottom. Hold the pedal, then close the screw. Release the pedal and push it again and open the bleed screw again, bottom the pedal and close the screw. Repeat a few times at each caliper and you should rid the system of any trapped air. You may have air trapped in the master cylinder, which the only good way to get it out is the pedal-pump method.

Good luck with it.

[Krynos]

I take mine to dealer for brake fluid flushing and replacing. $120 as stated above seems about right.

[ferocity02]

Originally Posted by Efthreeoh

Sounds like to me you got air in the system somewhere. Since I really can't figure out the procedure you used to bleed the system I'm not going to speculate. But I've been bleeding brakes on BMWs for nearly 30 years and just recently in the past 2 years have been using a Motive power bleeder. The old-timer's method of having someone pump the pedal while the other person opens and closes the bleed screw (dumping the fluid into a catch can with the hose immersed in fluid) will get any air out of the system. As the pedal is pushed, open the bleed screw and let the pedal slowly go to the bottom. Hold the pedal, then close the screw. Release the pedal and push it again and open the bleed screw again, bottom the pedal and close the screw. Repeat a few times at each caliper and you should rid the system of any trapped air. You may have air trapped in the master cylinder, which the only good way to get it out is the pedal-pump method.

Good luck with it.

Thanks, I may try that old-school method next.

Here was my method...
Use turkey baster to remove as much fluid from reservoir as possible
Top off reservoir with new fluid
Attach small air compressor to reservoir using the Motiv reservoir cap adapter (no Motiv bottle inline)
Turn on compressor up to 15-20psi
Go to caliper and open bleeder, fluid starts to come out
Let fluid flow until it comes out clean while occasionally turning on compressor to maintain 15-20psi
Once the fluid is coming out clean, close the bleeder
Release pressure and open reservoir
Add more new fluid (went through about ~1/2 reservoir per caliper)
Proceed to next caliper in standard order

[Efthreeoh]

Originally Posted by ferocity02

Thanks, I may try that old-school method next.

Here was my method...
Use turkey baster to remove as much fluid from reservoir as possible
Top off reservoir with new fluid
Attach small air compressor to reservoir using the Motiv reservoir cap adapter (no Motiv bottle inline)
Turn on compressor up to 15-20psi
Go to caliper and open bleeder, fluid starts to come out
Let fluid flow until it comes out clean while occasionally turning on compressor to maintain 15-20psi
Once the fluid is coming out clean, close the bleeder
Release pressure and open reservoir
Add more new fluid (went through about ~1/2 reservoir per caliper)
Proceed to next caliper in standard order

I've never really heard or seen anyone directly pressurize the reservoir from a compressor. I personally don't think it is a good technique. But to each his own.

But my advice is to try the old school method of bleeding the brakes first and see what you get. Going to a dealer with a bad brake pedal and explaining to them how you bled the system, the dealer is likely to give you some BS story that you damaged the master cylinder and recommend replacing it. Keep in mind they have liability issues to consider. Working on what to them is a defective brake system is a high-liability situation. If they simply take your word on how you bled the system and re-bleed it and get a firm pedal back and then the system fails a few days later and you have an accident because of it, they could be considered liable. So the dealer is going to be as cautious as possible to insure the system is in top-order working condition.

[boro92]

if there is no air in the abs system (you bled via INPA, so you are good), then your procedure is fine. Dry bleeding is actually smarter for frequent bleeds, as it reduces the need for bottle clean up and there is no chance of putting a little bit of older fluid back into the system (whereas you otherwise would if you put fluid into the motive bottle).

Is it possible that your MC is simply going? How is the pressure at a stop - can you make the pedal sink to the floor simply by resting your foot on the brake after you come to a stop? Also, obvious question - is the brake fluid brand new and never opened? And was it dot 3, 4, 5.1 or 5?

If the fluid wasn't dot5, and was brand new in a sealed bottle, there was no issue with how you bled. Bleeding it again would not produce different results--even with the OG method.

[John 070]

Originally Posted by ferocity02

Use turkey baster to remove as much fluid from reservoir as possible

imho this may be your problem.

Brake fluid is cheap, even DOT 4, so I would simply push the old out. I've never agreed with the turkey baster method, but if you want to do that, even a turkey baster is not the best device to use. Use a fluid pump that costs $5 at HFT instead, or even an antifreeze tester that costs $3 at Walmart. But again, I would simply use the motive to push all the fluid out, without trying to siphon any from the reservoir.

[John 070]

Originally Posted by boro92

Dry bleeding is actually smarter for frequent bleeds, as it reduces the need for bottle clean up and there is no chance of putting a little bit of older fluid back into the system

This is what I did and the tip came from the Porsche forum. Yes it's a PITA to have to undo the cap and add fluid to the car's reservoir, but I prefer no cleanup myself...

[Efthreeoh]

Well it takes about 5 minutes to clean the power bleeder with denatured alcohol. So if you bleed the system every two years it's not an issue in my book. The idea of having fresh fluid in the bottle is to prevent running the master cylinder dry. Someone said there is a risk of getting old fluid back in the system, but I don't see how that could happen if the reservoir is emptied of the old fluid and filled with new fluid and the bleeder bottle is full of fresh fluid.

The E90 brake reservoir is mulit-chambered, it may be possible to empty one chamber and the entire reservoir look like it is not completely empty. Somehow air got into your system using the dry method.

[GottWhat]

Previous owner had the brake fluid changed at a local dealer just over a year ago, they charged $118.82 ($109 for labor and $9.26 for fluid).

[Arby1028]

Originally Posted by Efthreeoh

Sounds like to me you got air in the system somewhere. Since I really can't figure out the procedure you used to bleed the system I'm not going to speculate. But I've been bleeding brakes on BMWs for nearly 30 years and just recently in the past 2 years have been using a Motive power bleeder. The old-timer's method of having someone pump the pedal while the other person opens and closes the bleed screw (dumping the fluid into a catch can with the hose immersed in fluid) will get any air out of the system. As the pedal is pushed, open the bleed screw and let the pedal slowly go to the bottom. Hold the pedal, then close the screw. Release the pedal and push it again and open the bleed screw again, bottom the pedal and close the screw. Repeat a few times at each caliper and you should rid the system of any trapped air. You may have air trapped in the master cylinder, which the only good way to get it out is the pedal-pump method.

Good luck with it.

I'm having a somewhat similar issue to the OP - my brake pedal feels a little soft at times. Other times I depress the pedal to stop and it has an little extra "give" to it. One other thing it has been doing is when I let off the brake pedal to accelerate from a stop it feels like the brakes momentarily stick and don't release immediately. Any thoughts on this? Thanks.

[Dabrwright]

I have the same issue where the brakes seem to stick on when starting from a stop. It doesn't happen all the time.
I spoke to an SA at the dealers and they say it is normal and something to do with the hill hold function, although I don't know why it should happen on level road.

[ferocity02]

Mine stick too sometimes, also heard it was normal.

[Arby1028]

Originally Posted by Dabrwright

I have the same issue where the brakes seem to stick on when starting from a stop. It doesn't happen all the time.
I spoke to an SA at the dealers and they say it is normal and something to do with the hill hold function, although I don't know why it should happen on level road.

We have a hill hold function??? It happens to me about every 5-6 stops.

Originally Posted by ferocity02

Mine stick too sometimes, also heard it was normal.

I don't think this is normal at all. Our X5 has the "Auto Hold" feature and it doesn't feel "sticky" like this at all. I may run by my Indy Shop this week and get them to take a look.