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-   -   Brake Bleeding Problem (https://xoutpost.com/bmw-sav-forums/x5-e53-forum/96554-brake-bleeding-problem.html)

LVP 06-05-2014 12:03 PM

I do that. I clear out as much as I can and fill with new fluid. I agree - why push through stuff you know isn't fresh. Just makes it all go a lot longer :)

squidzilla 06-05-2014 12:51 PM

Quote:

Originally Posted by TiAgX5 (Post 997060)
It's recommended that the res be pumped out/turkey bastered. If the res fluid is old/wet you dont want to push it thru the system.

The entire purpose of brake system flushing is keeping moisture exposure to a minimum.


Is that not the same two year old fluid that is presently in the entire system? I figured it was fine being in there for two years and would be fine being dripped out of the right rear caliper. It dripped about half of quart of clear fluid so I could be sure.

StephenVA 06-05-2014 03:24 PM

All the brake fliud should be flushed out. By removing all the liquid in the Reservoir first, than fill with new fluid, you will speed up your job as you do not have to "push" all of that fliud through the system before refilling the master reservoir with new clean fluid (no mositure) or discoloration.

Using a pressure bleeder pump makes the job easy as you get to flow a lot more liquid at one time than the older "foot on the brakes - pump it" method. Besides you avoid the chance of tearing up the master cylinder pump seals by pushing too far down the bore into the ruff and possible scaled area where the rubber mater cyl pump seals will get damaged.

Flush every two years and you will avoid a LOT of brake issues especially mosture damage to calipers and lines. :thumbup:

admranger 06-05-2014 06:08 PM

Quote:

Originally Posted by LVP (Post 997032)
Garrett I think that's the ticket. I think the pressure bleeder I'm using is part the culprit (Motiv).

I'm sorry, but the Motiv isn't the problem.

I've bled gallons of brake fluid over my 2 decades of track experience (HPDEs and a decade of racing where I bled before the race weekends and during the race weekends...). I've used a Motiv brake bleed for most of that time on a variety of cars (BMW) and trucks (Ford, Chevy). I've never had a problem with brakes being soft that was caused by the Motiv.

If you are introducing air into the system with the Motiv, you are doing something terribly wrong or I've been the luckiest person on the planet. My sample size in performing this operation is statistically significant. No small sample sizes here...

BTW: when you change brake pads, don't push the piston into the cylinder on the brake caliper without first opening up the bleeder. You don't want to push the crap that settles out in your caliper back up into the brake system.

BTW2: Use a small metal object to 'tap' the caliper as your are bleeding the brakes (I use the handle of a small ratchet wrench). That'll help release any stubborn air bubbles that are sticking to the caliper due to surface tension.

BTW3: Glad the brake problems of the folks in the thread have been solved!

LVP 06-05-2014 09:31 PM

Jury still out for me on the Motiv. But your experience is similar to the tons of others who post videos and swear by it. Now, the one i have may be very old, but it hold pressure. When I pump it up, I can hear it bubbling through the fluid. Last time I did my brother-in-law's car and we shone a light in the reservoir after removing the bleeder, it was full of micro bubbles. And his brakes went to crap. But I'll keep trying to find a way through with the pressure bleeding technique. I'm going to the shop tomorrow to try a pressure and vacuum bleed at the same time. I'll post results. I too find it hard to believe that many use the bleeder without issues.

For BTW: This is what I do - open the bleed screw, not letting the crud back up.
For BTW2: I use a dead blow hammer. Easier on the ears, same result.
For BTW3: I wish I was in this camp now. I'm not, but I most definitely will be :)

Cheers.

TiAgX5 06-06-2014 12:30 AM

Quote:

Originally Posted by squidzilla (Post 997072)
Is that not the same two year old fluid that is presently in the entire system? I figured it was fine being in there for two years and would be fine being dripped out of the right rear caliper. It dripped about half of quart of clear fluid so I could be sure.

The res fluid will usually have more moisture then the ABS module/line fluid, due to the res cap allowing more moisture absorption from the atmosphere.

LVP 06-09-2014 04:49 PM

The indy shop tried pressure, pedal and vacuum bleeding without success. I've suggested the following:
- bench bleed master
- use GT1 to block off the ABS channels and see if issue(s) lie in master/abs circuits or in one of the channels somewhere after the abs
- bleed with vehicle running
- crack fittings at master and abs while bleeding under pressure

Any other ideas? What kills me is it had a good pedal, I tossed on new pads rotors, backed out pistons with bleed screws open not forcing up fluid and then pressure bled fresh fluid through the system (no pedal presses, just pressure and let it run through until clean). Pedal is mushy but stops when off and mushy but goes slowly to floor with medium, consistent pressure when vehicle on. It does still stop, because I had it out to bed in pads/rotors. I'm baffled as is the shop - and these guys have done nothing but BMWs for the last 25yrs.

The shop is also going to swap in a master they have and see if that does anything. Could have just freed up some gunk when I pressure bled it and messed up the seals. I'll keep everyone posted. If I ever get it working, I'll report findings and never touch the bloody brakes again :)

SlickGT1 06-10-2014 10:56 AM

This is absolutely nuts. I can't believe the amount of issues a simple brake bleed seems to cause people.

I need to bleed my brakes desperately, but this seems to make me nervous. I need to get my laptop back to working order and fire up the GT1. I think the fail you guys experienced is by not doing this correctly from the start.

LVP 06-10-2014 11:58 AM

It isn't just reserved to us X53ers either. I've done some searching and it plagues more people than you can imagine. Now, I'm not an idiot, but I really can't see what I did wrong and a shop who has been doing this for 25yrs can't seem to fix it or explain it either. It's nuts, I agree. It should be as easy as this video below, but alas the Germans and their complex ABS/DSC/whatever-else systems tend to complicate things a bit. I laughed when I watched this video. Can you imagine doing the X5 master like this and it working?
Fixing A Sinking Brake Pedal


But check out some of these various threads for some head scratching. All over the map.

Porsche issues
Sinking brake pedal - Rennlist Discussion Forums

More pedal sinking - pads this time?
Changed the brake pads - now the pedal sinks in

More bmw mysteries
e39 sinking brake pedal

See post #18 and #20. Bloody hell
http://www.xoutpost.com/bmw-sav-foru...s-floor-2.html

See post #2 and the pdf it references - these brake systems are so simple - unreal
Brake Pressure Sensor (DSC/ABS/BRAKE Trifecta) - Bimmerfest - BMW Forums

squidzilla 06-10-2014 12:15 PM

Well I did a gravity bleed on my 330xi, 545i manual, and the 3.0 e53 x5 and had zero issues. Even my beater Passat 1.8 wagon got a gravity bleed.

Until I understand why people using bleeders are having these problemsr this is how I will do my brakes. It does take longer but you get a feel for how fast it is dripping on and you can check in on it every ten or fifteen minutes to keep the res topped off. I don't let it get much lower than the max line while doing this.


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