Question on E30 Brakes

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BeemaBoy
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Thu Jan 12, 2006 10:34 am

Hey Everyone

Just a quick question on the brakes. On my E30, to get the brakes to just about bite, I have to push the pedal down just over half way. This, after driving another persons new Mazda, seems to be a little far. Eventhough, the brakes work perfectly and stop the car instantly, everytime!

The amount of travel just seems weird though :?

It is a 320i with 4 disc brakes, and almost new pads.

Any suggestions from others?

Many Thanks
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Thu Jan 12, 2006 11:02 am

My 325i and old 320i was the same, the pedal would travel about 1-2 inchs before the breaks would bite, but after the that, they were really sharp. It might be down to the age of the car's.

It might be worth just bleeding the breaks to remove the air, or look at the rubber hose's for any bulging under pressure.....
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Thu Jan 12, 2006 11:17 am

I've never really been inspired by the brakes on my 325, discs have plenty left on them (grooved & drilled too), new pads, rest of the system looks to be in good order with new master cylinder etc about 3 years ago.

I think if you have been driving more modern stuff, there is just no comparison. Even getting into a P reg 406 td I nearly found myself peeling my face from the windscreen on the first dab of the brakes.
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Thu Jan 12, 2006 11:21 am

I will agree with you there......

You cant really compare newer cars more efficiant(sp) breaking systems to a system that was designed 20+ years ago.....

Aslong as the system is up to spec, stops the car when i want it to, thats fine.....
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Thu Jan 12, 2006 12:09 pm

I think this is one of the problems with our RHD cars that are 'converted' from LHD. Also, one of the reasons why converted M3's seem to loose braking power.
I've read on here that the linkage is adjustable, but it's not something to mess with unless you know what you are doing.
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Thu Jan 12, 2006 12:19 pm

I think if you have been driving more modern stuff, there is just no comparison. Even getting into a P reg 406 td I nearly found myself peeling my face from the windscreen on the first dab of the brakes.
Agree completely!
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Thu Jan 12, 2006 12:38 pm

Yes don't be fooled by new cars aparrent "better" brakes. They may be sharp but with this increased sharpness you may loose control.

Drove a new citroen not that long ago and i could pull up sharply with my little toe! Is that really nessesary?

I believe that having to put less and less effort into driving is dangerous with people understnading less and less how actually are car handles and works.

Read this;
http://driving.timesonline.co.uk/articl ... 18,00.html
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Hyperion
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Thu Jan 12, 2006 12:51 pm

Simon wrote:I think this is one of the problems with our RHD cars that are 'converted' from LHD. Also, one of the reasons why converted M3's seem to loose braking power.
I've read on here that the linkage is adjustable, but it's not something to mess with unless you know what you are doing.
i dont think LHD drive is the be all and end all of cars and RHD are their poorer cousins. I do agree with you about the converted cars thou, i think (correct me if i am wrong) it has to do with the brake system being right behind the pedals, and when you covert to RHD the braking system doesnt move with the pedals, Problem with space and how the engine was designed in the M3. I think if BMW had enough time to design the M3 they would have worked out a workable solution for the RHD cars. I believe I read that BMW were playing catch up with the Mercs and needed a car that could compete in the shortest time possible.
I am open to ideas and criticism on this :roll:
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Thu Jan 12, 2006 12:53 pm

Hyperion wrote:
Simon wrote:I think this is one of the problems with our RHD cars that are 'converted' from LHD. Also, one of the reasons why converted M3's seem to loose braking power.
I've read on here that the linkage is adjustable, but it's not something to mess with unless you know what you are doing.
i dont think LHD drive is the be all and end all of cars and RHD are their poorer cousins. I do agree with you about the converted cars thou, i think (correct me if i am wrong) it has to do with the brake system being right behind the pedals, and when you covert to RHD the braking system doesnt move with the pedals, Problem with space and how the engine was designed in the M3. I think if BMW had enough time to design the M3 they would have worked out a workable solution for the RHD cars. I believe I read that BMW were playing catch up with the Mercs and needed a car that could compete in the shortest time possible.
I am open to ideas and criticism on this :roll:
?? I didn't say nothing about LHD being the be all and end all!

It's a fact...the E30 is german, and designed as a left hand drive car, hence the servo being located behind the pedal, but for the right hand drive cars, there's more linkages before the servo, hence removing some of the feel from the pedal, and adding more travel.
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Thu Jan 12, 2006 1:07 pm

ok dude , i understand, just taht i have conversations with other guys and they were always ragging on about LHD blah blah blah.
If the system we run in our car is a hydralic system, the signal from the servo will have to travel the same distance regardless if it is left or right in the engine bay. so the "slowness" we feel is caused by the distance the "signal" has to travel from the pedal to get to the servo. This problem has been sorted out today with most cars running a electronic assisted system.
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Brianmoooore
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Thu Jan 12, 2006 1:13 pm

E30BeemerLad wrote:I've never really been inspired by the brakes on my 325, discs have plenty left on them (grooved & drilled too), new pads, rest of the system looks to be in good order with new master cylinder etc about 3 years ago.

I think if you have been driving more modern stuff, there is just no comparison. Even getting into a P reg 406 td I nearly found myself peeling my face from the windscreen on the first dab of the brakes.
Pedal pressure has nothing to do with how good a cars brakes are. Have you ever driven a single seat race car? Braking power like you wouldn't believe, but you nearly have to dislocate your hip to apply it.
I regularly drive a couple of modern cars as well as my E30s, and the E30 brakes are every bit as good as the modern ones.
Your new brake master may be a clue to your problems, if the cross car pull rod wasn't adjusted properly. Adjust it so it pushes the brake pedal up just short of the stop.
If that doesn't sort it, then you have air in the system, or swelling brake hoses, or a caliper/disc/hub problem which is pushing a caliper piston too far off the disc, or a combination of all three.
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BeemaBoy
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Thu Jan 12, 2006 1:33 pm

E30BeemerLad wrote: I think if you have been driving more modern stuff, there is just no comparison. Even getting into a P reg 406 td I nearly found myself peeling my face from the windscreen on the first dab of the brakes.
Here here! My experience was with a new Ford Falcon XR6. I have never driven anything with so much stopping power. Just touch the brakes and the car comes to a skid less, perfect stop...Needless to say...2 people have run into the back of his car!!!

Don't get me wrong though, the E30 brakes are great and as I said earlier are excellent. Just need to push the pedal a bit more than modern cars :wink:

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Thu Jan 12, 2006 1:42 pm

Brianmoooore wrote:
E30BeemerLad wrote:I've never really been inspired by the brakes on my 325, discs have plenty left on them (grooved & drilled too), new pads, rest of the system looks to be in good order with new master cylinder etc about 3 years ago.

I think if you have been driving more modern stuff, there is just no comparison. Even getting into a P reg 406 td I nearly found myself peeling my face from the windscreen on the first dab of the brakes.
Pedal pressure has nothing to do with how good a cars brakes are. Have you ever driven a single seat race car? Braking power like you wouldn't believe, but you nearly have to dislocate your hip to apply it.
I regularly drive a couple of modern cars as well as my E30s, and the E30 brakes are every bit as good as the modern ones.
Your new brake master may be a clue to your problems, if the cross car pull rod wasn't adjusted properly. Adjust it so it pushes the brake pedal up just short of the stop.
If that doesn't sort it, then you have air in the system, or swelling brake hoses, or a caliper/disc/hub problem which is pushing a caliper piston too far off the disc, or a combination of all three.
Cheers Brian, you are a legend - or is that leg end? :mad:
will look into that :D Will be chuffed if that is the solution as i had just come to the conclusion E30 calipers were guff and was even looking at after market stuff like Hi-Spec calipers last year.

I agree with your point about single seaters etc, i drove a Ginetta G33 at Croft last year, NO SERVO, practically pulling myself out the seat to get some braking done, but once you find some bite it is all good. You certainly have better control over the braking when a servo isn't dragging the pedal to the floor for you. It all boils down to familiarity at the end of the day.
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Thu Jan 12, 2006 1:47 pm

I agree with everything said above re: old cars vs new cars.

To add to this however, I've owned & driven quite a few other german cars (BMW, Audi & VW) and I have to say that ALL of them from mid/late eighties to mid/late ninties (reg date) had the same trait, that is no braking or feel for the first 1-2 inches then strong bite and good braking. I don't know why but I reckon it was a "German" thing, you know what I mean, none of the Jap cars I've had or driven felt the same.

I've upgraded the brakes on my car: grooved & drilled discs, EBC pads, Goodridge hoses & DOT5 fluid. Still has the same characteristic, only bites harded and more consistent especially in the wet (when warmed up that is, the EBC Green Stuff pads are cack when cold, need to get 'em heated up before any serious braking). I'd say they don't fade as quickly but still only lasted 10 laps on a short circuit before feeling like glass! I reckon it's the pads, so anyone with experience of other fast road/track pads let me know!

There's nowt seriously wrong with your brakes mate, though bleeding them wouldn't hurt.
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Fri Jan 13, 2006 10:40 am

E30 brakes are great when you get used to them, My missus has a new polo and that is over-servo'd to the point of having the ABS kicking in on wet roads.

When I've driven her car for a few days my e30 brakes feel a bit wooden but after 10 mins or so they feel fine again.

Have you ever driven a new Nissan Micra ? the brakes on those are something else, a little tickle on the pedal and you've got got 'NASSIN' imprinted on your forehead. Fecking dangerous they are 8O

Cheers,

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Fri Jan 13, 2006 11:17 am

If your brakes are lacking in feel or the pedal has slack travel then it is worth investigating...

1. completely drain the brake fluid from the system...
2. renew all the caliper/cylinder rubber seals
3. renew all flexible hoses
4. refill and bleed the system with a racing style brake fluid (AP 550 or similar)

If you want more feel and less pedal pressure then REDUCE the size of the master cylinder bore..
I seem to recall that there is a kit for E30 M3s (might fit other models, too) that does that by making the cylinder bore smaller. This means that you have to push less to acheive the same braking effort...

Not necessarily a good thing IMHO, though, as you loose the smoothness of a more progressive pedal.

The ultimate braking effort is down to the wheel caliper/piston and the pad/disc contact area and cooling, too...Bigger brake discs, calipers with more and/or bigger pistons and bigger pad surface will increase the actual stopping power.
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Fri Jan 13, 2006 11:22 am

garyp_E30_325i wrote: I've upgraded the brakes on my car: grooved & drilled discs, EBC pads, Goodridge hoses & DOT5 fluid. Still has the same characteristic, only bites harded and more consistent especially in the wet (when warmed up that is, the EBC Green Stuff pads are cack when cold, need to get 'em heated up before any serious braking). I'd say they don't fade as quickly but still only lasted 10 laps on a short circuit before feeling like glass! I reckon it's the pads, so anyone with experience of other fast road/track pads let me know!
I've used EBC green stuff pads on a couple of vehicles.....They a re "fast road" pads and not really any good for circuit use...

They also produce an incredible amount of dust!

Try Ferodo DS2500...they offer better performance than green stuff, fade less and dust less, too...Mintex M1144 are good, too

The EBC red stuff pads are better circuit pads, but need more heating up so are unsuitable for road use....
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Fri Jan 13, 2006 11:40 am

I've used EBC green stuff pads on a couple of vehicles.....They a re "fast road" pads and not really any good for circuit use...
Not that good for road use either... :roll:
Try Ferodo DS2500...they offer better performance than green stuff, fade less and dust less, too...Mintex M1144 are good, too
Thanks for the recommendation, I used to like Mintex but not used them for a long time (last car I remember them on was a MkII Escort...)

I've had Ferodo sport pads on a bike, they were good, might give 'em a go. :D
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Fri Jan 13, 2006 12:02 pm

If anyone has a chance, try a Mazda MX5 or Mazda Miata. Very sharp brakes aswell. Does not help that the car is so damn light too.

I actually really put my E30 brakes through the paces yesterday, just for fun. They really are awesome brakes! No fade, and they stop. I tried slamming on anchors a few times from 60 - 70 mph and the car stops with no skidding or juddering.

These E30's are expensive but awesome cars! Who needs a girlfriend when you can spend money on ur Beema winkeye

Thanks
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Fri Jan 13, 2006 1:38 pm

I fail to see what "improvenments" have been made to the average car's disc brakes in the last twenty years.
Current fashion for larger wheel rims with rubber bands for tyres allows bigger discs, but that's about all.
Atmospheric pressure 20 years ago was about 15 lbs/sq.", the same as it is today, so there's nothing difficult about designing a servo to give what ever assistance the designers choose.
E30 designers chose a certain level of assistance, probably based on a few million pounds worth of research. The greater assistance offered on most cars today is probably a result of a move towards more female friendly cars.
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Fri Jan 13, 2006 1:53 pm

[quote="Fushion_Julz"]

If you want more feel and less pedal pressure then REDUCE the size of the master cylinder bore..
I seem to recall that there is a kit for E30 M3s (might fit other models, too) that does that by making the cylinder bore smaller. This means that you have to push less to acheive the same braking effort...



quote]

No not reduce,increase. Its a bigger master cylinder bore that makes it better.The one your thinking of for the m3 is a 7 series one and is a direct replacement.It has a 25 mm piston instead of the standard 23 mm one.More push means less travel on the pedal
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Fri Jan 13, 2006 2:02 pm

Large movement on small cylinder = Small Movement on Large cyclinder.

This requires more effort from the smaller cylinder, but has greater control over the lager cylinder

Small movement on Large cylinder = Large movement on small cylinder.

Little effort required on larger cylinder to move the smaller cylinder, but very hard to control smaller cylinder

Most braking systems are based on the first example of Hydraulics.......
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Fri Jan 13, 2006 2:11 pm

the 25 mm master cylinder gives an 18 % increase.

So really its still large movement on small cylinder=Small movement on large cylinder just the small cylinder is a bit bigger.Still smaller than the caliper cylinder.
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Fri Jan 13, 2006 2:12 pm

move towards more female friendly cars.
True!

Even transit vans and buses are female friendly now! Not that there is anything wrong with that,

but I like to feel like I'M doing some work when breaking, make's you feel at one with the car a bit more i think.
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Fri Jan 13, 2006 2:19 pm

buster wrote:the 25 mm master cylinder gives an 18 % increase.

So really its still large movement on small cylinder=Small movement on large cylinder just the small cylinder is a bit bigger.Still smaller than the caliper cylinder.
Thats my thinking, the smaller, longer bore master cyclinder has to act upon four shorter, larger bore caliper cyclinders, giving better control.

imagine how the brakes would feel if it was the other way around, the caliper cylinders would shoot out of the calipers at great speed, and cause the pads to smack into the disks. the effect would be like " All on or All off and no middle ground "
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Fri Jan 13, 2006 8:55 pm

Fushion_Julz wrote:
I've used EBC green stuff pads on a couple of vehicles.....They a re "fast road" pads and not really any good for circuit use...

They also produce an incredible amount of dust!
:eek:

It's strange that, i have ebc greenstuff (latest version) on the scirocco on brembo max gorrved discs and i really can't fault them at all.
The rocco also has the brake master cylinder on the left and a pull rod system but the ebc pads out perform the old pagidFR pads i had from cold and produce far less dust eaven when they get a proper paisting down some local roads (used to be used as a night rally stage) :mad:
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Fri Jan 13, 2006 9:06 pm

i dont agree about the ebc redstuff ceramic, i have them on my touring and i find them fine when cold for normal road driving. obviously they do need to heat up for serious braking but id say they are the best set up ive used, they dont seem to fade ,the harder i press the harder they bite.
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Sat Jan 14, 2006 12:44 am

Well,

if you pussies were using your left foot for a bit of braking (LHD drivers excluded!) then i dont think we'd have any complaints about the E30 braking system!!!
Know what im sayin!! winkeye
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Sat Jan 14, 2006 1:01 am

my brakes are pretty sharp from top of pedal


325 touring with abs.......just fade at continuous high speed


and they have average joe shite fitted


have got the new kit though when get round to fitting,thought id warp me old discs properly first ....lol.....vfm
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Sat Jan 14, 2006 11:37 am

I think what we are trying to say on the master cylinder subject is that a smaller diameter master cylinder will produce greater force at the caliper for the same force applied to the pedal but will require more pedal travel.

Basic hydraulics.

Cheers,

Iain T
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