E36 M3 brake all around, 25mm BMC, PEDAL STILL SPONGEY!!

[wazzu70]

Look at Lee's manual brake conversion for pictures. You will want to move the linkage the opposite direction though to reduce pedal travel.

[berlow94]

Which linkage?


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[E30stan]

Which linkage?


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I think referring to the manual brake conversion, or booster delete, but that is not what im looking to do for my daily.

Im really hoping to hear some feedback from those with the 25mm brake master cylinder installed.

[wazzu70]

The 25mm master will make your pedal feel much more firm. You need to get an adjustable proportioning valve though.

The E30 has a stepped master cyl with different piston diameters for front and rear. The 25mm master cylinder has 25mm in both front and rear.

If I remember correctly the regular E30 master is 22mm/19mm.

[MyE30]

As stated earlier, you will have a hard time bleeding the air out of your brake system if you calipers are installed upside down (bleed valves pointed down).

I noticed you retained your air pump. Is the motor BARed?

[E30stan]

The 25mm master will make your pedal feel much more firm. You need to get an adjustable proportioning valve though.

The E30 has a stepped master cyl with different piston diameters for front and rear. The 25mm master cylinder has 25mm in both front and rear.

If I remember correctly the regular E30 master is 22mm/19mm.

That is quite relevant information, would you happen to have any suggestions for said propportioning valves?

As stated earlier, you will have a hard time bleeding the air out of your brake system if you calipers are installed upside down (bleed valves pointed down).

I noticed you retained your air pump. Is the motor BARed?

I have yet to try to rebleed with the caliper pointed upwards, but it seemed to bleed just fine?

I kept everything stock s52 obd2 just for simplicity since i had an entire e36 to part out. Im over on the east coast, no bar stuff over here, yet anyhows

[Todd Black 88]

It will bleed fine, but air will be trapped at the top of the caliper, away from the bleeder. Air compresses and gives a spongy pedal.

[MyE30]

It will bleed fine, but air will be trapped at the top of the caliper, away from the bleeder. Air compresses and gives a spongy pedal.

^this

If your bleeder valves are pointed down it's because you have the calipers swapped left to right and right to left (probably already been stated previously).

[E30stan]

It will bleed fine, but air will be trapped at the top of the caliper, away from the bleeder. Air compresses and gives a spongy pedal.

Well, today i removed the calipers in such a way that the bleeders were pointed upwards. As i suspected, they were indeed bleed properly, as in, no air bubbles escaped. Im somewhat aware of a spongey pedal due to air being in the lines, this situation probably has more to do with the brake biasing. Im on the lookout for a proportioning valve solution.

^this

If your bleeder valves are pointed down it's because you have the calipers swapped left to right and right to left (probably already been stated previously).

Im well aware of the proper placement of the calipers. Funny thing was that even with the bleeders pointed downward i was able to bleed all the air out of the system. This was probably due to the fact that i used a combination of a vacuum pump at the bleeder and manually pumping the pedal. Regardless, it seems as though the 25mm front and 25mm rear proportioning of the 750i brake master cylinder creates a less than ideal pedal feel, in conjunction with the original e30 proportioning valve. This means more upgrading soon!

[Wanganstyle]

sounds like a faulty used master cylinder + upside down brake calipers; is the original
e30 brake master cylinder faulty?

E36 m3's don't have issues with brake feel out of the box bone stock. something sounds wrong and perhaps a combination of items

[MyE30]

Properly placing the capliers on the correct sides of the car and re-bleeding the brake system seems to be the cheapest troubleshooting step, IMO.

Is there a reason why prefer them to be on the wrong sides?

[E30stan]

sounds like a faulty used master cylinder + upside down brake calipers; is the original
e30 brake master cylinder faulty?

E36 m3's don't have issues with brake feel out of the box bone stock. something sounds wrong and perhaps a combination of items

The original e30 master cylinder is not faulty but i dont want to use it because i increased the piston size from 43 to 60 in the front and 33 to 40 in the rear.
Also a stock e36 m3 brake master cylinder pumps 25.4 mm of fluid to the front and 22-23 to the rear, the 750i e32 bmc pumps 25.4 front and rear.

Properly placing the capliers on the correct sides of the car and re-bleeding the brake system seems to be the cheapest troubleshooting step, IMO.

Is there a reason why prefer them to be on the wrong sides?

Ill report back to you once i install the wilwood proportioning valve thats on the way.

[Wanganstyle]

The original e30 master cylinder is not faulty but i dont want to use it because i increased the piston size from 43 to 60 in the front and 33 to 40 in the rear.
Also a stock e36 m3 brake master cylinder pumps 25.4 mm of fluid to the front and 22-23 to the rear, the 750i e32 bmc pumps 25.4 front and rear.



Ill report back to you once i install the wilwood proportioning valve thats on the way.

Who cares about the number of whatever it pushes; if the part is bad it's unsafe to have on a street going vehicle; especially in a braking component; if it fails on the street and you hurt someone ELSE......

Why not just run the e36m brake master?

Use known perfect parts (new) and install them correctly.

Please stay away from me any anyone I know and care about on public roads until you have a properly functioning brake system.

Some aftermarket prop valve won't help you here.


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[E30stan]

Who cares about the number of whatever it pushes; if the part is bad it's unsafe to have on a street going vehicle; especially in a braking component; if it fails on the street and you hurt someone ELSE......

Why not just run the e36m brake master?

Use known perfect parts (new) and install them correctly.

Please stay away from me any anyone I know and care about on public roads until you have a properly functioning brake system.

Some aftermarket prop valve won't help you here.


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Wanganstyle,
Has anyone told you that you come across as an arrogant person? I dont want this to turn into some gladiatorial event, but you replied very rudely while i merely stated the facts.

Have you ever ran recycled parts on a car?

Do you realize we are on opposite coasts?

Although everyones entitled to their own opinion, I'm curious to hear actual experience related to my particular scenario; combination of parts.

I dont care to read your response, but will be entertained if you take the bait:)

[Wanganstyle]

E36 M3 brake all around, 25mm BMC, PEDAL STILL SPONGEY!!

Wanganstyle,
Has anyone told you that you come across as an arrogant person? I dont want this to turn into some gladiatorial event, but you replied very rudely while i merely stated the facts.

Have you ever ran recycled parts on a car?

Do you realize we are on opposite coasts?

Although everyones entitled to their own opinion, I'm curious to hear actual experience related to my particular scenario; combination of parts.

I dont care to read your response, but will be entertained if you take the bait:)

You posted a thread for advice; Here is the advice you have been ignoring the entire time.

Your symptoms are (besides the Upside down calipers)

Bad master cylinder.

Seems you have been avoiding this advice all along and don't really wish the car fixed.
Nobody gives a rip about your feelings; there is an entire genre of music devoted to this; it's called EMO

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