1990 535i Brake Bleeding nightmare

[xtmsports]

Hey guys,

I have a 1990 BMW 535i, it drives great, except for the nightmare brake issue.

I've replaced the 4 rotors, pads, calipers, and master cylinder.

My problem is that I can not figure out how to get rid of the air in the system, its ruined a whole set of brake pads and i have had to turn the front rotors too, due to uneven stopping.

I was told that i needed to Pressure Bleed the system since it has ABS.

Can somebody PLEASE explain to me the procedure for pressure bleeding, I have read so many different variations and I am confused.

I hope somebody can plainly explain the correct procedure to pressure bleed the system. Currently, my BMW isn't the ultimate driving machine, its the ultimate nightmare on wheels, already thinking about selling the thing and buying a car with brakes that work.

Thanks.

[Kalevera]

?! Didn't we talk about this one like a day or so ago?

Anyway, a pressure bleeder is a device that allows you to use compressed air to force the old fluid (and any air) out of the system. Instead of jamming on the brakes, you connect a device to the fluid reservoir fill cap and give it some air pressure (from shop air or...heck...a bicycle pump would probably do the trick). Bruno sells the device on his racingking.ca site; you can easily make one of your own (pressure gauge (not really necessary - but useful), NPT male, teflon tape, a T connector, and a cap for the reservoir), or pick a generic one up at the local auto parts place.

Be sure to remove all of the old fluid from the reservoir, then pour the new in (I usually fill it all the way up...it's just going down anyway since the pistons are mostly compressed with new brake pads). Bleed in this order: rear pass, rear driver, front pass, front driver. It's a good idea to check the reservoir fluid level as you go along, but there's enough in there to do AT LEAST the rears, probably all of them, before you top it off for a test drive.

Also, as was communicated last time -- *don't* turn BMW rotors. The OEMs are soft and once they've got a significant lip, they need to be replaced. It sucks, but that's part of the design. I'd rather stop right than not. Having said that, I recall reading that Don Gale did some minor resurfacing in the past with good results because he didn't want to buy new rotors (read his brake writeup).

Good luck!

best, whit

[xtmsports]

After the previous post, I went out to Autozone and purchased a pressure pump, but it didn't have anything to do with the brake fluid resevoir cap. It attached to the brake caliper bleed screw. So it totally confused me. I pumped the bleeder device and opened up the bleeder screw. I did that about 10 times for each wheel, but the brakes still have air in them. I think I did it wrong or something. So was confused.

I guess I need to buy the bleeder from Bruno to solve my problems.

So, if the brakes start to pulsate, i am not suppose to turn the rotors? That's weird. Well, I turned both the front rotors once already, maybe that is what's causing my problems and not air in the system. However, I still have spongy brakes and occasionally, I can feel the calipers burp some air and slip a bit.



?! Didn't we talk about this one like a day or so ago?

Anyway, a pressure bleeder is a device that allows you to use compressed air to force the old fluid (and any air) out of the system. Instead of jamming on the brakes, you connect a device to the fluid reservoir fill cap and give it some air pressure (from shop air or...heck...a bicycle pump would probably do the trick). Bruno sells the device on his racingking.ca site; you can easily make one of your own (pressure gauge (not really necessary - but useful), NPT male, teflon tape, a T connector, and a cap for the reservoir), or pick a generic one up at the local auto parts place.

Be sure to remove all of the old fluid from the reservoir, then pour the new in (I usually fill it all the way up...it's just going down anyway since the pistons are mostly compressed with new brake pads). Bleed in this order: rear pass, rear driver, front pass, front driver. It's a good idea to check the reservoir fluid level as you go along, but there's enough in there to do AT LEAST the rears, probably all of them, before you top it off for a test drive.

Also, as was communicated last time -- *don't* turn BMW rotors. The OEMs are soft and once they've got a significant lip, they need to be replaced. It sucks, but that's part of the design. I'd rather stop right than not. Having said that, I recall reading that Don Gale did some minor resurfacing in the past with good results because he didn't want to buy new rotors (read his brake writeup).

Good luck!

best, whit

[Kalevera]

Yeppers...the idea is to push the old fluid out of the master cylinder and lines via the reservoir. I would just pick up a new set of brembos, be sure to scrub them to get rid of the cosmolene, and then bleed the system. Should be good after that :)

best, whit

[632 Regal]

yep, need pressure where you add the fluid not where you take it out, the reason being it squished the air pocket small enough to pass through the ABS unit where without pressure it will just hang out like you witnessed.

If your roter is warped you need a new one...period. If you turned them you need new ones...period.

Sorry but thats how it works.

[53589]

1st check for fluid leaks second start with wheel fartest from master cylinder(back right wheel)then pump brake pedal 3 times (need two people)on third pump hold brake down and signal ur asstistant too bleed screw as it starts coming out have the do three quick pumps again hold on third and tighten bleed screw continue to each caliper tillu finish i gurantee u'll wont paass ur next stop sign good luck this allways works for me it's called manual brake bleeding

[632 Regal]

not once air is in the ABS unit, try it!


it's called manual brake bleeding

[Dash01]

That blows. You need something that sucks. (Don't we all?)

Go to a pet or farm supply place (that caters to horse owners) and buy a large (2oz./60 cc) plastic syringe, for ~89 cents. At a hardware store buy ~3-4 feet of clear vinyl ~ 1/4" inside diameter tubing, for ~10 cents/foot.

Put one end of the vinyl tube onto the brake nipple (start with PS rear, per other posts) and the other end of the tube onto the syringe. Top off the brake reservoir, loosen the bleed nipple, and have sombody slowly pump the brake pedal while you pull the plunger in the syringe. This sucks the old fluid and air from the line. Keep the tube elevated above nipple level, just to make sure no air gets back into the system. (Duct tape is helpful here, but you can string it into the spring coil or whatever if you're too cheap for duct tape.)

You can see the fluid color change in the clear vinyl tube as new fluid replaces old. When the fluid runs clear and bubble-free, tighten the bleed nipple and repeat the process at the left rear wheel, then right front, then left front, always being sure to keep the brake reservoir topped off and the vinyl tube elevated, so you're not pumping air in from that end. I use the old brake fluid bottle as a depository for the used brake fluid. If you're really cheap, you don't even need the syiringe, just keep the clear tube elevated so no air gets in, while pumping the brake pedal. When I do this, I tape the outlet end of the tube so it's fixed at the bottom of the old brake fluid bottle, below the level of some old fluid I leave in there. This makes sure no air can get back in.

The syringe deal can be done for less than $2.00, plus brake fluid. Works as well as or better than Mighty Vac or whatever else there is in the aftermarket. If you're worried about cross-contamination of the syringe during later use in other procedures (such as when changing differential oil), just use another disposable 89 cent syringe.



Hey guys,

I have a 1990 BMW 535i, it drives great, except for the nightmare brake issue.

I've replaced the 4 rotors, pads, calipers, and master cylinder.

My problem is that I can not figure out how to get rid of the air in the system, its ruined a whole set of brake pads and i have had to turn the front rotors too, due to uneven stopping.

I was told that i needed to Pressure Bleed the system since it has ABS.

Can somebody PLEASE explain to me the procedure for pressure bleeding, I have read so many different variations and I am confused.

I hope somebody can plainly explain the correct procedure to pressure bleed the system. Currently, my BMW isn't the ultimate driving machine, its the ultimate nightmare on wheels, already thinking about selling the thing and buying a car with brakes that work.

Thanks.

[Bill R.]

furthest point and bleed first , typically the right rear wheel, then left rear then right front then left front. This should pretty much cover everything if you have any other questions let me know.http://www.bimmernut.com/%7Ebillr/images/brakebleeder1%20copy.jpg












Hey guys,

I have a 1990 BMW 535i, it drives great, except for the nightmare brake issue.

I've replaced the 4 rotors, pads, calipers, and master cylinder.

My problem is that I can not figure out how to get rid of the air in the system, its ruined a whole set of brake pads and i have had to turn the front rotors too, due to uneven stopping.

I was told that i needed to Pressure Bleed the system since it has ABS.

Can somebody PLEASE explain to me the procedure for pressure bleeding, I have read so many different variations and I am confused.

I hope somebody can plainly explain the correct procedure to pressure bleed the system. Currently, my BMW isn't the ultimate driving machine, its the ultimate nightmare on wheels, already thinking about selling the thing and buying a car with brakes that work.

Thanks.

[rbeaud]

Not to be rude, but brakes may not be something you play with if the process is not clear to you.

That said, I encourage you to become more knowledgeable and give it a go. There's already plenty of good info in this thread. Brake bleeding is fairly simple. I made my own brake bleeder. See the link. The total cost was around $30. Yeah, Motiv makes one that looks nicer, but I like that I made mine.

http://www.apexcone.com/JimPowellHomepage/Bleeder/bleeder.html

With this kind of bleeder, you pour fluid in the sprayer, use the plunger to build 10 psi and start cracking bleeder nipples. It is better to use pressurized fluid to push like this than to suck using a vacuum on older cars; the hoses may be constricted due to swelling or collapse under vacuum.

Also, if you have not used the ABS for a panic stop, why would you have air in the ABS module? If you do, the dealer can cycle the module as could a really good independant.

Cheers,

Roland


Hey guys,

I have a 1990 BMW 535i, it drives great, except for the nightmare brake issue.

I've replaced the 4 rotors, pads, calipers, and master cylinder.

My problem is that I can not figure out how to get rid of the air in the system, its ruined a whole set of brake pads and i have had to turn the front rotors too, due to uneven stopping.

I was told that i needed to Pressure Bleed the system since it has ABS.

Can somebody PLEASE explain to me the procedure for pressure bleeding, I have read so many different variations and I am confused.

I hope somebody can plainly explain the correct procedure to pressure bleed the system. Currently, my BMW isn't the ultimate driving machine, its the ultimate nightmare on wheels, already thinking about selling the thing and buying a car with brakes that work.

Thanks.

[xtmsports]

Thanks for the procedure Bill. One question, during the 12 pumps, do I leave the engine on or off?

Thanks



furthest point and bleed first , typically the right rear wheel, then left rear then right front then left front. This should pretty much cover everything if you have any other questions let me know.http://www.bimmernut.com/%7Ebillr/images/brakebleeder1%20copy.jpg

[Bill R.]

1
Thanks for the procedure Bill. One question, during the 12 pumps, do I leave the engine on or off?

Thanks

[632 Regal]

Bill.... it is possible to bleed the ABS if air gets into there with standarb bleeding procedure????

Call me dumbass with this then. I HATE people giving false information and I have been the king lately if this is true.

[xtmsports]

Bill, I tried Bruno's pressure bleeder and followed the instructions you supplied.
All the wheels were fine except for the front driver caliper. Even though my wife stepped on the pedal 12 times with the bleeder open, it had a diffucult time coming out. Does that mean i need a new hose for the front driver caliper?

Since it was coming out slow, I had my wife pump the brake 5 times and then held it down with some force, then I opened up the bleeder screw and brake fluid was forced through. I did this about 4-5 times. But I still feel a little bit of grabbing coming from the front driver caliper.

Would you suggest that i need a new front driver brake hose?



furthest point and bleed first , typically the right rear wheel, then left rear then right front then left front. This should pretty much cover everything if you have any other questions let me know.http://www.bimmernut.com/%7Ebillr/images/brakebleeder1%20copy.jpg

[Bill R.]

try swapping the 2 front bleeder valves in case its a bad bleeder valve not letting the fluid out. If after you swap it then i would suspect a brake hose next.






Bill, I tried Bruno's pressure bleeder and followed the instructions you supplied.
All the wheels were fine except for the front driver caliper. Even though my wife stepped on the pedal 12 times with the bleeder open, it had a diffucult time coming out. Does that mean i need a new hose for the front driver caliper?

Since it was coming out slow, I had my wife pump the brake 5 times and then held it down with some force, then I opened up the bleeder screw and brake fluid was forced through. I did this about 4-5 times. But I still feel a little bit of grabbing coming from the front driver caliper.

Would you suggest that i need a new front driver brake hose?