1986 E30 325i brake upgrade

[e30-wheels]

Just done a front 4 pot caliper conversion using Willwood calipers and larger discs.
For normal road use no real difference to stock brakes maybe a bit more bite, fast road a little bit better than stock brakes, but that could be the Pads, still got the mushy pedal feel with plenty of travel which if you try to take out buy linkage adjustment the brake can bind when hot. All in all a wast of money, knowing what i know now i would have left the brakes as standard.

[mikemike]

hi from mike , had a problem with my brakes , always didn't feel right , changed the master cylinder for a 25mm 7 series one , made a lot of difference feels like I have brakes now , cost of a 7 series master cylinder is around £160 , bit of a cheap fix

[jmc330i]

From what I've read in the past the Wilwood calipers often need a larger master cylinder as they aren't matched to the E30 master cylinder.

[ross_jsy]

What size pistons are they?

WMS's work very well out of the box as they are only fractionally larger than standard pistons

[jmc330i]

What size pistons are they?

WMS's work very well out of the box as they are only fractionally larger than standard pistons

Keri specced the WMS calipers for that exact reason. The Wilwood caliper commonly used on E30s has a larger piston area that needs a bigger master cylinder.

[etouring]

Iv had Wilwood dynalite with 280 disk fitted for about a year now. After I first fitted them I also felt disappointed with pedal travel but now I really like them. I thought about trying the 25mm master but never got round to fitting one. Iv got a second e30 with Audi s2 2 pot floating calipers on 312 disks, they don't look as cool and are much heavier but work about the same for half the price. Oh I almost forgot the Wilwoods took loads of bleeding

[e30-wheels]

The guys that have done the Wilwood set up say the the original caliper piston area is not much different to the original caliper and should not effect the master cylinder. As i still have the mushy pedal feel something is not correct, saying that when the brakes get warm to hot the pedal feel is more or less ok much firmer, i might try a 25 mm master cylinder just to prove a point, Bleeding the Wilwoods was no problem, if you open the bottom bleeders it apparently draws air into the system. Just another though is air hanging up in the abs unit, I had a Jeep Grand Cherokee that had a mushy feel to the brakes after a new abs unit was fitted it had to be bleed by jeep in the end, apparently they have to activate the abs unit to get rid of the air, im told this is normal practice on a lot of cars, Don't know how one would do that on a E30, any one got any ideas!!

[Brianmoooore]

If you've managed to get air into the depths of the ABS unit, then it will have to be activated manually to bleed it properly.

[hennared323i]

If you've managed to get air into the depths of the ABS unit, then it will have to be activated manually to bleed it properly.

What he said

[etouring]

That sounds sounds the same as mine, after using the brakes a few times the pedal gets firmer. It dose feel like air is trapped...

[keri-WMS]

What size pistons are they?

WMS's work very well out of the box as they are only fractionally larger than standard pistons

Keri specced the WMS calipers for that exact reason. The Wilwood caliper commonly used on E30s has a larger piston area that needs a bigger master cylinder.

[Jozi]

If you've managed to get air into the depths of the ABS unit, then it will have to be activated manually to bleed it properly.

How is this done? I've rep limbed the whole lot and no doubt have air in the abs unit.

[DanThe]

It can be done by slackening the pipes one at a time at the ABS unit, master to ABS first, then the outlets, then the calipers, by gravity only. Ive done it this way lots of times without problems. You can also bleed the system backwards if you have a caliper full of fluid with no air

[e30-wheels]

Any one know if there is a way to activate the ABS electrically?, this is what jeep do.

[Brianmoooore]

Air should only get trapped inside the ABS unit if the ABS was activated while there is air in the pipes. Draining the pipes and refilling/bleeding the system with the car off shouldn't cause this problem.
Consequently, I've never had to activate the ABS block manually, but if the occasion arose, I would use this circuit diagram: http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig06.pdf to identify the connections to the solenoids in the block, and would then pulse them with a 12 volt power supply while pressure bleeding the brakes normally.

[e30-wheels]

Thanks for the information, The complete brake system has been overhauled with new pipes and all the components including the abs unit thoroughly cleaned. Thats what they did with my Jeep pulse the abs unit

[e30-wheels]

just took a look at the wiring circuit my car is an 1986 would it be the same as a 1990

[Ianb]

Just done a front 4 pot caliper conversion using Willwood calipers and larger discs.
For normal road use no real difference to stock brakes maybe a bit more bite, fast road a little bit better than stock brakes, but that could be the Pads, still got the mushy pedal feel with plenty of travel which if you try to take out buy linkage adjustment the brake can bind when hot. All in all a wast of money, knowing what i know now i would have left the brakes as standard.

I totally agree with the above, i used mazda 4 pots, and had to use spacers which i hated and i didn't think it was worth it at all. Standard discs all round are good enough if the system is in good condition.

[Brianmoooore]

just took a look at the wiring circuit my car is an 1986 would it be the same as a 1990

No, there are significant differences with the pre '88 system, BUT the relevant bits are the same.

[ross_jsy]

Just done a front 4 pot caliper conversion using Willwood calipers and larger discs.
For normal road use no real difference to stock brakes maybe a bit more bite, fast road a little bit better than stock brakes, but that could be the Pads, still got the mushy pedal feel with plenty of travel which if you try to take out buy linkage adjustment the brake can bind when hot. All in all a wast of money, knowing what i know now i would have left the brakes as standard.

I totally agree with the above, i used mazda 4 pots, and had to use spacers which i hated and i didn't think it was worth it at all. Standard discs all round are good enough if the system is in good condition.

A proper braking system is far better than some poorly sized Willwoods or a hodge podge of bits off an old Mazda. The standard brakes are very easy to overheat if you use them hard.

[JayCorsa4]

Hi have u got braided lines fitted? Also did u bleed the system throughly?

[etouring]

Air should only get trapped inside the ABS unit if the ABS was activated while there is air in the pipes. Draining the pipes and refilling/bleeding the system with the car off shouldn't cause this problem.
Consequently, I've never had to activate the ABS block manually, but if the occasion arose, I would use this circuit diagram: http://www.autolib.diakom.ru/CAR/BMW/19 ... /fig06.pdf to identify the connections to the solenoids in the block, and would then pulse them with a 12 volt power supply while pressure bleeding the brakes normally.

What about letting the car idle so the vacume works, surly it would be ok if you not moving.

[ross_jsy]

I don't think you understand a cars braking system if you think the vacuum to the servo has anything to do with the abs pump

[reggid]

my standard brakes are well maintained and in good condition. they are still a complete disgrace though worst aspect of the car , you can lock the brakes up and get good retardation but the pedal is extremely nonlinear meaning there is very little action initially almost mushiness (im told the small MC design is the reason)before you start to get any sort of bite, i'm hoping there is something i have overlooked but my mechanic who has owned as many e30s as anyone and has worked on the e30 since they came out says they are normal.

i'm toying with the idea of a properly put together wilwood setup from massive brakes in US purely from a pedal feel point of view. i don't need the resistance to fade as i don't usually drive in a manner that causes issues in this area. i want a setup that bites hard as soon as you breathe on the pedal so that stopping power in an emergency is there. at the moment i have zero confidence in them

[keri-WMS]

The standard soft pedal is the reason for the 1.25" piston size option on the WMS kits.

On the face of it, the spec of the car suggests using 1.38" pistons (the other option we offer), but often going for the improved pedal that the 1.25" size offers is more important for people and most customers take this option.

[reggid]

Keri, so the smaller the piston results more or less pedal travel?

how does the bigger 25mm MC that some seem to "upgrade" to affect piston size requirements?

[etouring]

I don't think you understand a cars braking system if you think the vacuum to the servo has anything to do with the abs pump

Brian wrote "bleeding the system with the car off shouldn't be a problem" I know the vacum servo has nothing to do with the abs but was not sure if the abs was active when the car is at idle.

[keri-WMS]

Keri, so the smaller the piston results more or less pedal travel?

how does the bigger 25mm MC that some seem to "upgrade" to affect piston size requirements?

Smaller caliper pistons and/or larger MC = less travel but less mechanical advantage.

(and vice versa)

The WMS kits are designed to not need a larger MC (esp the 1.25 size), if you do fit one though you get an "even harder pedal" to an increasing degree!

[e30-wheels]

What size pistons are they?

WMS's work very well out of the box as they are only fractionally larger than standard pistons

Keri specced the WMS calipers for that exact reason. The Wilwood caliper commonly used on E30s has a larger piston area that needs a bigger master cylinder.

Pistons are 4x1.25

[e30-wheels]

The willwood i used are 4x1.25, somone asked if i had braided pipes ,yes stainless

[reggid]

which wilwood calipers were they? ones ive seen typically 1.38" or 1"

[e30-wheels]

Willwood Midi kit for BMW E30 , Apparent they sell a lot into Germany mainly for Track days and racing, i will double check the piston size of the actual calipers i have fitted to make sure i have been supplied the correct ones, when i looked up the spec some time ago there were several different piston sizes for the Midi
Caliper.

[etouring]

I don't think you understand a cars braking system if you think the vacuum to the servo has anything to do with the abs pump

I know the servo has nothing to do with the abs, you have misunderstood what I have said. Brian wrote "bleeding the system with the car off shouldn't be a problem". If you have car the running there would be power going to the abs dose this mean it's active? Or would it only activate under heavy braking?

[Brianmoooore]

ABS does nothing until activated. In its quiescent state, the ABS block will just bleed straight through, as if it was just short pieces of pipe. Air will not get into the inner chambers of the block, but, similarly, any that is there already, will not be expelled.

[e30-wheels]

Just checked my E30 325 Willwood Midilite Kit caliper piston size they are 1.25 so should match the M/C ok.
Minilite do 4 sizes 1.75,1.5.1.38 an 1.25. The mushy pedal feel must be air in the system or the M/C I dont think its to do with the crossover linkage as it appears from what i have read LHD cars suffer the same pedal feel.