Click to go to Forum Home Click to go to maXbimmer Home

Go Back   maXbimmer Forums > maXimum Tech > 3 Series > E30 (1983 - 1991)
User Name
Password


Welcome to Maxbimmer.com!

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

Reply
 
Thread Tools Rate Thread Display Modes
Old 12-11-2011, 06:54 PM   #1
InfiniteDice
14 Years with the E30
 
InfiniteDice's Avatar
 
Join Date: Sep 2006
Location: St. Catharines
Posts: 1,126
Brakes are giving me the breaks.

Seriously I'm no newbie to thins crap but I'm not having any luck.

So..

I swapped out my master for another good master I had figuring it might solve my recently softer than usual pedal feel.

Didn't change anything.

So I figured hey... it must be a seal the booster then. So I changed my ATE booster out with the shinier Girling one I had sitting on a shelf for a few years.

So after all the BS of swapping it out... I go to bleed the right rear and get my GF to pump it up then hold... I loosen the bleeder and drop.... .... .... drop.. ... . So it's not holding pressure, I even pulled the bleed screw right out.

Now I'm wondering if the Girling booster is compatible with the ATE master I'm using.

Tomorrow I'm going to try all over again swapping to another ATE booster I found, I know it works but it's not as pretty as the Girling.

Another question... the valve on the booster to throttlebody hose, is that supposed to let air into the throttle body? or let air from the throttle body into the booster?

Thanks guys. It must be something simple. And yes I have a new seal between the master and the booster.
__________________




Performance one step at a time.
InfiniteDice is offline   Reply With Quote
Old 12-11-2011, 07:10 PM   #2
Red_Rocket
2nd Gear Member
 
Red_Rocket's Avatar
 
Join Date: Aug 2007
Location: Shitby
Posts: 153
Yes, that hose is supposted to be there. That is how your vacuum booster gets vacuum, and thats why your pedal feels different when your cars not running.
Red_Rocket is offline   Reply With Quote
Old 12-11-2011, 07:31 PM   #3
DIY
Permanently Dirty
 
DIY's Avatar
 
Join Date: Aug 2010
Location: Etobicoke
Posts: 527
so what he means to say is its sucking air to the throttle body....

could you have pinched a brake line from hitting something?
considering the brakes should work without vacuum, I find it hard to believe that the booster would be the problem...

the only thing I can think of is theres a pinch/blockage... unless something could be backwards
DIY is offline   Reply With Quote
Old 12-11-2011, 08:10 PM   #4
Ceeker
Parts hoarding partner...
 
Ceeker's Avatar
 
Join Date: Nov 2007
Location: Toronto
Posts: 3,333
how about changing the dribbling caliper? maybe it it contaminated? Try bleeding the other side to see if you get the same result.
the throttle body sucks air from the booster creating a vacuum.also may want to try to pull the line free from the caliper and see if you get flow when you depress the pedal.
__________________

I think I've had 14 bmw's in 4 years.
2 IX's -sold and parts
2 325i 4 dr - sold
4 318is all white - sold and parts
1 87 325is red - parts
1 89 325i vert grey - parts
1 90 325is white - keepin
1 87 325i vert -red - keepin
latest addition 1 88-325is red - parts
latest addition 1 89-325i vert - white -fixin/sold
latest addition 1 92-318i vert - blue - parts
latest addition 1 87 325is blk - parts.

latest addition as of 2013-Gold 87-325is auto! it's a keeper!

Last edited by Ceeker; 12-11-2011 at 08:15 PM.
Ceeker is offline   Reply With Quote
Old 12-11-2011, 10:19 PM   #5
dble Trouble
TAKE IT TO THE TRACK
 
dble Trouble's Avatar
 
Join Date: Nov 2005
Location: Scarborough
Posts: 1,868
Ernie clear your inbox man, it's full and I couldn't send you a pm. Email me asap please! john_venditti@hotmail.com

Sorry for the thread jack but need to talk to da boss!
__________________

BMW 325I E30 Chumpcar Race Car
BMW 540iT M-Sport (New Family Hauler)
BMW 135i Msport Daily/track toy
dble Trouble is offline   Reply With Quote
Old 12-12-2011, 03:51 PM   #6
InfiniteDice
14 Years with the E30
 
InfiniteDice's Avatar
 
Join Date: Sep 2006
Location: St. Catharines
Posts: 1,126
Okay, well swapped out the swapped in booster. Yes I'm tired.

Turns out the Girling booster didnt have that metal shaft inside the booster hole, that goes into the master hole... lol.

So I borrowed my neighbors pressure bleeder and bled the calipers. Now I have pressure but it's not that good. Kinda like I need to go 1/2 down before it has pressure.

I'm going to try re-bleeding tomorrow, maybe there is some air someplace.

I hate brakes. I'm used to having brakes that can lock up the tires.
__________________




Performance one step at a time.
InfiniteDice is offline   Reply With Quote
Old 12-12-2011, 05:45 PM   #7
InfiniteDice
14 Years with the E30
 
InfiniteDice's Avatar
 
Join Date: Sep 2006
Location: St. Catharines
Posts: 1,126
Okay I drove to the store and if I mash the pedal down fast I can lock up the front tires. I just don't like how it has crappy light pressure response. I get light response about 1/2 way down then it starts actually doing something.

Grrr. might just pony up some dough and get that larger master from the 7 series. Anyone here using that with an e30 ATE booster?
__________________




Performance one step at a time.
InfiniteDice is offline   Reply With Quote
Old 12-12-2011, 07:04 PM   #8
Ceeker
Parts hoarding partner...
 
Ceeker's Avatar
 
Join Date: Nov 2007
Location: Toronto
Posts: 3,333
Quote:
Originally Posted by dble Trouble View Post
Ernie clear your inbox man, it's full and I couldn't send you a pm. Email me asap please! john_venditti@hotmail.com

Sorry for the thread jack but need to talk to da boss!

hey John, called your house...left message.
__________________

I think I've had 14 bmw's in 4 years.
2 IX's -sold and parts
2 325i 4 dr - sold
4 318is all white - sold and parts
1 87 325is red - parts
1 89 325i vert grey - parts
1 90 325is white - keepin
1 87 325i vert -red - keepin
latest addition 1 88-325is red - parts
latest addition 1 89-325i vert - white -fixin/sold
latest addition 1 92-318i vert - blue - parts
latest addition 1 87 325is blk - parts.

latest addition as of 2013-Gold 87-325is auto! it's a keeper!
Ceeker is offline   Reply With Quote
Old 12-12-2011, 07:08 PM   #9
Ceeker
Parts hoarding partner...
 
Ceeker's Avatar
 
Join Date: Nov 2007
Location: Toronto
Posts: 3,333
Quote:
Originally Posted by InfiniteDice View Post
Okay I drove to the store and if I mash the pedal down fast I can lock up the front tires. I just don't like how it has crappy light pressure response. I get light response about 1/2 way down then it starts actually doing something.

Grrr. might just pony up some dough and get that larger master from the 7 series. Anyone here using that with an e30 ATE booster?
I'd say the best thing is gravity bleed the brake system first. then proceed with bleeding through the pedal. it's hard to determine why they get half peddle or late pedal response. It can be a number of things. If sufficient vacuum is available and there are no audible leaks then you should be getting a good pedal providing there is absolutely no air in the lines. I just did my cabrio because the pedal was hard and braking was delayed. I changed the booster, master, seal and bleed the system completely. I have lock up happening at half pedal. I used used parts since I had them lying around. the brakes work fine now. But it doesn't respond like my coupe.

I would keep bleeding the brake system. you may still have air. did you bench bleed the master? I wonder if air can be trapped in the ABS pump?
__________________

I think I've had 14 bmw's in 4 years.
2 IX's -sold and parts
2 325i 4 dr - sold
4 318is all white - sold and parts
1 87 325is red - parts
1 89 325i vert grey - parts
1 90 325is white - keepin
1 87 325i vert -red - keepin
latest addition 1 88-325is red - parts
latest addition 1 89-325i vert - white -fixin/sold
latest addition 1 92-318i vert - blue - parts
latest addition 1 87 325is blk - parts.

latest addition as of 2013-Gold 87-325is auto! it's a keeper!

Last edited by Ceeker; 12-12-2011 at 07:41 PM.
Ceeker is offline   Reply With Quote
Old 12-13-2011, 11:53 AM   #10
InfiniteDice
14 Years with the E30
 
InfiniteDice's Avatar
 
Join Date: Sep 2006
Location: St. Catharines
Posts: 1,126
No abs. Hence it's very simple. I'll re-bleed it and see what happens.

My only question is... when you press the brake pedal down with the car off, should the one way valve between the booster and the TB blow air? I can hear a hiss from my air filter when my trusty GF pushes the pedal down.
__________________




Performance one step at a time.
InfiniteDice is offline   Reply With Quote
Old 12-13-2011, 12:13 PM   #11
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,717
Quote:
Originally Posted by InfiniteDice View Post
No abs. Hence it's very simple. I'll re-bleed it and see what happens.

My only question is... when you press the brake pedal down with the car off, should the one way valve between the booster and the TB blow air? I can hear a hiss from my air filter when my trusty GF pushes the pedal down.
It's not blowing air, it's releasing the vacuum. Yes it should do that. They have that valve so if car shuts off you'll retain regular braking force for at least one application of the brakes (i.e. to stop safely).
__________________
Bullet Ride is offline   Reply With Quote
Old 12-13-2011, 01:01 PM   #12
InfiniteDice
14 Years with the E30
 
InfiniteDice's Avatar
 
Join Date: Sep 2006
Location: St. Catharines
Posts: 1,126
Yeah I figured it would release the vacuum at some point, it can't just build vacuum indefinitely.

On some cars you'll see the one line coming off the brake booster, it then divides into two lines... one goes to an open port on the throttle body on the intake side of the TB and plugs into the air boot before the TB. The other line dead ends at a closed off throttle body port.

My system has the one line. Coming from the brake booster it goes into the one way valve, then into a plastic connector, from there the plastic connector plugs into the rubber intake boot and goes to a small port on the TB.

I'm not familiar with the logic of this routing. Why does the booster release air in front and in behind the TB at the same time? I've read that the engine vacuum is what opens the valve, but if that's true then why can I blow through it so easily?

Perhaps the engine vacuum counteracts the air coming from the booster to prohibit the flow from the booster, but since it's one way it can't actually supply air to the booster.

Okay I need a coffee.
__________________




Performance one step at a time.

Last edited by InfiniteDice; 12-13-2011 at 01:07 PM.
InfiniteDice is offline   Reply With Quote
Old 12-13-2011, 03:31 PM   #13
Bullet Ride
Cars in Perpetual Repair
 
Bullet Ride's Avatar
 
Join Date: Nov 2007
Location: Guelph
Posts: 5,717
Quote:
Originally Posted by InfiniteDice View Post
Yeah I figured it would release the vacuum at some point, it can't just build vacuum indefinitely.

On some cars you'll see the one line coming off the brake booster, it then divides into two lines... one goes to an open port on the throttle body on the intake side of the TB and plugs into the air boot before the TB. The other line dead ends at a closed off throttle body port.

My system has the one line. Coming from the brake booster it goes into the one way valve, then into a plastic connector, from there the plastic connector plugs into the rubber intake boot and goes to a small port on the TB.

I'm not familiar with the logic of this routing. Why does the booster release air in front and in behind the TB at the same time? I've read that the engine vacuum is what opens the valve, but if that's true then why can I blow through it so easily?

Perhaps the engine vacuum counteracts the air coming from the booster to prohibit the flow from the booster, but since it's one way it can't actually supply air to the booster.

Okay I need a coffee.
The cars with the two line set-up have that second hole in the TB finished, itís not a dead end. BMW eventually revised the system to the single line on the late model cars and stopped finishing the one hole on the TB. I think the original idea behind the dual line is to help maintain good vacuum to the booster during open throttle conditions (for left foot trail braking while racing) but I donít know that for a fact.
__________________
Bullet Ride is offline   Reply With Quote
Old 12-13-2011, 04:00 PM   #14
El Gato Liso
6th Gear Member
 
El Gato Liso's Avatar
 
Join Date: May 2007
Location: Brampton
Posts: 3,078
im using a 7 master on my 3 booster, works lovely and i even discovered my ABS actually works!
__________________
R.I.P. E30
El Gato Liso is online now   Reply With Quote
Old 12-13-2011, 04:10 PM   #15
InfiniteDice
14 Years with the E30
 
InfiniteDice's Avatar
 
Join Date: Sep 2006
Location: St. Catharines
Posts: 1,126
So if air can pass from the booster to the engine without passing the afm/maf then wouldn't that affect the control of metered air?

Cool, thanks Gat. The prices are getting stupid on some parts. I'm going to try bleeding these brakes a couple more times, a few days apart to be sure it isn't an air pocket someplace, if that fails I'll think about the 7 series master, it's only slightly more $$$ than the e30 ones.
__________________




Performance one step at a time.

Last edited by InfiniteDice; 12-13-2011 at 04:14 PM.
InfiniteDice is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 05:58 AM.


Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.