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Discussion Starter #1
this might be out of most folks here.. but my car has front brake drag..:confused::( brake sat up.. 4 piston front caliper, vented front disk... calipers are rebuilt they work perfectly. new disk..my wheel bearing are set well..my problem is ( i think) lack of runout on the rotor.so the brake pads are running on the disk...i am thinking ablout putting a .5 mm washer/spacer on one of the studs of the front rotor. this will effect the rotor very slightly overall. the washer will go between the rotor and the rear of the hub..i am assuming that this will give a slight amount of runout on the rotor and realease the pads ever so slightly, as compared to the full rub i am getting now...the capiler piston colapse easly enoguh with a ladgr plyer, as all the calipers do with no out pressure..with the front wheels in the air they do not spin, it takes a wee bit of pressure to spin the wheels.as you can imagine the gas mileage is suffering a bit..am i on the right tract?
 

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Discussion Starter #2
...heres is the math.. disk size 278 mm bolt circle.....108 mm....centre to outer end of the disk 139mm.. centre to bolt circle 54mm did some drawings 1 mm moves the disk out on the spacer side 3mm..not good..so i think .5 mm spacer will work better the disk would wobble( for the lack of better words:) ) only 1.5 mm, enough to push the pistons back a little and allow for the disk/hub not to drag.....i inviting better idea's here.:):)
 

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Every disc brake caliper I've ever worked on (none exotic though - MG, Alfa, Honda motorcycle, Chevy, etc) rely on the seals grip on the piston to slightly retract the piston. The seals - like large square section O-rings - distort slightly as the brakes are applied and then pull the piston back that slight amount when hydraulic pressure is released. Hub/rotor run-out is not used to knock the pads back.

Rotor run-out or loose hub bearings cause a problem - the pads end up too far from the rotors and the first application of the pedal is used up getting the pads back where they belong.

Are the pads hanging up in the calipers? I've had sets of pads with so much paint on them that they didn't move freely in the caliper. Are you certain the calipers are functioning properly? Are you sure all hydraulic pressure is being released when the brake pedal is 'off'? I've had faulty brake hoses act like one-way valves - letting brake pressure in to the brakes but restricting return flow. I've also had a master cylinder gasket that didn't allow full return stroke which partially blocked a fluid passage. (that was in an MGA)
 

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Every disc brake caliper I've ever worked on (none exotic though - MG, Alfa, Honda motorcycle, Chevy, etc) rely on the seals grip on the piston to slightly retract the piston. The seals - like large square section O-rings - distort slightly as the brakes are applied and then pull the piston back that slight amount when hydraulic pressure is released. Hub/rotor run-out is not used to knock the pads back.

Rotor run-out or loose hub bearings cause a problem - the pads end up too far from the rotors and the first application of the pedal is used up getting the pads back where they belong.

Are the pads hanging up in the calipers? I've had sets of pads with so much paint on them that they didn't move freely in the caliper. Are you certain the calipers are functioning properly? Are you sure all hydraulic pressure is being released when the brake pedal is 'off'? I've had faulty brake hoses act like one-way valves - letting brake pressure in to the brakes but restricting return flow. I've also had a master cylinder gasket that didn't allow full return stroke which partially blocked a fluid passage. (that was in an MGA)
Drive it and find out what caliper is sticking. Usually will be the hottest wheel.
It is hard to tell what could be the issue here as you have modified the original set-up with one from another vehicle.

Re-bleed the system to make sure there is no air.

Most of the time a dragging caliper is due to a faulty MC. Brake lines collapsing can for sure cause this as well.

Jason
 

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...It is hard to tell what could be the issue here as you have modified the original set-up with one from another vehicle.
This is why I didn't venture to offer any thoughts, as they wouldn't be based on prior Alfa experience. One thing you need to consider bianchi1 is that the more non-Alfa components that you fit into your Spider, the less applicable our Alfa experience becomes... I'm glad to see that Eric's background is broader and he's offered some good pointers.

Best regards,
Enrique

P.S. Your a patient man, Jason, especially considering how hard you tried to warn bianchi1 about the potential consequences...
 

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Discussion Starter #7
.. hey the car stops:):) i checked the temp. with my trusty lazer temp probe.. they are the same.. just a slight drag... and as for modifications.. we all do it..look at jugle justice car..again i feel that if i change my alfa in anyway it is wrong.. but others here do the same things to there alfa's , i.e. diff. fuel injection systems. motors ect/ that's ok...perhaps we all should go back to org parts on our cars.. skimmy tire no koni's no polly bushings,no porting of the heads,no cd players...
 

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I didn't see anyone say it was wrong. All that's being said is that we are more knowledgeable about Alfa stuff. Maybe you should check with folks who have cars with those calipers to see if there is an issue with the pistons not retracting.
 

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.. hey the car stops:):) i checked the temp. with my trusty lazer temp probe.. they are the same.. just a slight drag... and as for modifications.. we all do it..look at jugle justice car..again i feel that if i change my alfa in anyway it is wrong.. but others here do the same things to there alfa's , i.e. diff. fuel injection systems. motors ect/ that's ok...perhaps we all should go back to org parts on our cars.. skimmy tire no koni's no polly bushings,no porting of the heads,no cd players...
Ahh man. Seriously you have a lot to learn. First off I would like to see your Engineering degree and at least 5-10 years or more of on the job experience with braking systems, injections system suspension systems and so forth you mention.
The braking system is one system on the vehicle that messing around with and having no real knowledge of can cost you your life, someone else's life or your precious car just for bigger brakes. For standard street driving or even some spirited driving the Stock set up if in top notch condition using a good brake fluid, performance pads (rotors that have been skimmed prior to replacing pads), good brake lines, calipers (boots), MC and so forth are pretty **** good. I have never see a real need to upgrade them. A simple pad change with a rotor skim can make the biggest difference in the world.

You keep bringing up people who are extremist! Jj, the spider guy building that crazy car. You think these guys don't have their issues they have to figure out, they do. Personally a headache in my book.

Now do you also realize how much money Alfa spent on the brake system alone? Most likely MILLIONS!!!!! You realize they had no need to change the setup that much even up to 1994 with the CE edition spider?
Why you ask? No need to. Although there are some things that can always be a bit better than OEM, sometimes you actually do take a step backwards.

As I mentioned before, I think your not gaining much more than you already had and now you have a headache on your hands.

IMO Original parts are very good, since when did ATE become a crappy component. ATE is one of the best around.
I would have spent the money on rebuilding the calipers, new rotors (slotted even), good pads, steel lines, good fluid, new Brake MC or rebuild if needed and called it a day.

Now if you keep driving it I suspect you will warp you rotors soon enough if in-fact they are dragging. You have Stock rears right? They are sticking to I am guessing since this is a guessing game with an upgrade like this?
Well to me that points again to a MC. But who knows!

I have done a brake upgrade on my own vehicle this summer. What did I use? OEM parts.
My 1991 164S has a different set up than the 94> models.
5mm thicker rotors, 3mm larger piston (54mm to 57mm), much larger Booster (by 150mm) , and larger MC. Why did they do this? Because they realized the older set up was in need of a change. So they changed it. Why did they not do it to the spider as well. No need to. If the spider went on for another few years like the 164 I am sure they would have kept it the same. I have owned a few spiders and all stop on a dime, just not clear on why you needed to mess with this? Was it the bigger more colorful caliper?

I replaced my whole system with one from a 94 24V.
Direct bolt in but I replaced everything above. I know for a fact that it will work and fit fine as the cars share almost everything else besides a different motor. This set up did not change brake bias or cause any issues.
The braking was increase dramatically and I have documented the whole deal in the 164 section. Now some folks are just replacing the boosters alone for added braking for the pre 94

But I do not recommend using anything from another car due to the fact that you made up the carriers? If so I would bet that they are not as precise as OEM.

My point? Your comparing apples to watermelons! From all your posts that I have tried my best to read I can see right away you do not have the expertise to mess with the MOST important component on your vehicle...literally!!!

Sure it stops. But put that stopping in a emergency situation and I can guarantee your $50 upgrade will not perform. Like I said, think about? Millions spent on R&D for the spiders braking system and your $50 braking system? Hmm. I agree I would not want to be anywhere around you on the road. I wish this country had laws against this junk. It is dangerous and uselss most of the time. But if there is a kit built by someone like Tarox or MOVit at least they have done the engineering and use the proper materials and machining to get it right.

Anyways, good luck. I would not doubt the MC, the new calipers could have caused it to fail.

Looks like the wise thing, is to go back to OEM parts (been there done that,I have tried many after-market items and removed them for OEM as they are much better). I think so. But what do I know:rolleyes:

Jason
 

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Discussion Starter #10 (Edited)
,, you are right.i am just a damned fool..i work for 15 years at audi / vw as a tech took all the courses. front end ,brakes f.i., etc..love the job.. alas.. about 7 years ago i/freinds noticed i was having trouble talking.. so i went to the dr..great news.....parkinsons....oh-boy lots of fun...oh yes lost my job as a tech becaues of some insurance geek told the dealership i was a risk/hazard..yea..i love those insurance geeks..all 350 pounds of that bastard.....me a risk?..let's see i still race bicycles, fence ,and ski.. i am just looseing the ablitly to speak very slowly..yea..i am a damned fool i will just put on the old unported head.. stock cams.. that wonderfull ceramic fuse box..really don't need those fancy bladed fuses., and those stainles steel braded brake line.. why go there ,those nice flexy rubber lines are great.oh yes one more thing.. taking off those 205/50/16 wheels andd tire.. not stock...guess i must go back to the standard wheels 185/70/14.. let's just keep her stock. not go over 55 mph....
 

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Discussion Starter #11 (Edited)
$50.00???? i had the calipers checked at the mazda dearship where i work, after i rebuilt them ..get this..with factory Mazda parts...and the mount.. local porshe shop help me design them and make them..nice guy..know them for 20 years..:):) the mounts are perfectly centred..( just .021 off centre )yes i am a jurk....oh yes.. the problem..fixed.. got some minds togeather at the dealership durring lunch..re-adjusted the wheel bearing with the tire/wheel on..was adjusting them with the wheel off. got the wheel bearing really nice,, just a very slight amout of play.. you can barely feel it.. but just enought to get the rotor to shimmy enough to push the pads back a wee bit after i let the brake pedal off..i was adjusting thre bearing as per this site,, but the rotor was running too true.. no flutter,, so the apds where not retracting any into there bores...ad my freinds at wor.. perhaps a totla of 80-90 years of exp. between them...got to go,,,fenceing class is tonight:):) hope my parkenson doe's not come back tonight(..hummm,love to see that 350 pound heath /fitness guy agian.. love to fence with him...)
 

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,, you are right.i am just a damned fool..i work for 15 years at audi / vw as a tech took all the courses. front end ,brakes f.i., etc..love the job.. alas.. about 7 years ago i/freinds noticed i was having trouble talking.. so i went to the dr..great news.....parkinsons....oh-boy lots of fun...oh yes lost my job as a tech becaues of some insurance geek told the dealership i was a risk/hazard..yea..i love those insurance geeks..all 350 pounds of that bastard.....me a risk?..let's see i still race bicycles, fence ,and ski.. i am just looseing the ablitly to speak very slowly..yea..i am a damned fool i will just put on the old unported head.. stock cams.. that wonderfull ceramic fuse box..really don't need those fancy bladed fuses., and those stainles steel braded brake line.. why go there ,those nice flexy rubber lines are great.oh yes one more thing.. taking off those 205/50/16 wheels andd tire.. not stock...guess i must go back to the standard wheels 185/70/14.. let's just keep her stock. not go over 55 mph....
***?:confused:

Dude I don't even understand any of this?
This is a waste of my time.

You are all over the place with your stories. Audi/Vw tech now? Wow that is amazing. Where did you get trained and for how long? I have also taken VW/AUDI tech classes at UTI where my Father-in-law teaches it, a few BMW and Mercedes classes as well.
Mazada dealership checked out your caliper upgrade?? I am sure there insurance will not cover you bringing in a modified spider with mazada calipers to have the tech's check it out, waste their time, or whatever...I don't care! Trust me if you have ever worked as a tech for VW/AUDI you should know that would not happen unless it was an independent dealer but even then they rarely would do such a thing!!
BTW, if your VW/AUDI trained you would not need a mazda tech to check it out? Once trained on basic braking systems that should have been a piece of cake, what with 15 years of Audi/VW training and hands on experience.
But then not a month or so ago you where slapping stickers for Hyundai on peoples German cars like a 17 year old, defacing the German car owners cars using a advertising gorilla tactic in the totally wrong fashion.
Now you work for Mazada all of a sudden? Do you have an instant 15 years experience there as well? With all this knowledge how does a simple brake problem confuse you enough to ask a forum for help?
Just confused? 20 years knowing this Porsche guy? 15 years working for VW/AUDI, Working for Hyundai and also working for Mazada? You must have a collective experience of 50-70 years. Again with that experience this brake issue should have been a breeze but then again with this experience and knowledge you would have never done it either. Most tech's I know hardly stray from OEM.
Really a spider is not a difficult car to work on or diagnose for someone with such extensive knowledge and training. Is this your second life?

Listed top speed of the 1990 Spider for example is only 119mph. Or somewhere in that range.

I think the brakes are well equipped enough to stop the car at even 100mph let alone 55mph, 75 80 or 90mph. I have driven plenty of our modified spiders on the track with stock braking systems and never had any issues. On the street well they are just as good as anything else on the road that is DOT approved as well as TUV/Italian Road Authority approved. Remember that they use the same thing on the alfa spiders in Europe. If the brakes could not stop the car at high speeds they would not approve the car for use on public roads let alone pass any of the hard MOT or other European inspections. I have also been in some bad situations with my spider and I can tell you the brakes saved me a few times.

Anyways....


Good luck.
 

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the problem..fixed..

just a very slight amout of play..

enought to get the rotor to shimmy enough to push the pads back a wee bit after i let the brake pedal off..
(note to self: do not let this dealership work on the brakes of any car I own.)

HEY! Rotor shimmy/run-out is NOT used to "push back the pads". That is the job of the caliper itself. The pistons should retract slightly when you release the brake pedal. The pads may continue to lightly touch the rotors but with no force being applied.

Sorry, I don't like your idea of a 'fix'.
 

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Discussion Starter #14 (Edited)
..i work at mazda as a salesperson now, along with subarus and hyundai's...got it..issues?? try a few weeks with this stupid problem...it a lot of laughs..... i have had only 2 jobs in my life.. 6 years in the u.s army.. ft. gordon for basic, and ft. benning for m.o.s. training..and ft, irwin ca. for more training, then went to my first love.. working on cars..try looseing a large part of you income.. selling hyundai's and subarus? yes.. .i love her folks buying new car saying '' i want invoice'' i bet you know that one..right?? invoice for you last car..of course not.. you never aked for it..you are a good person , never wrong?? right... moreever i am a nice calm guy.. lot's of freinds. some even on this board have met me..in person..i never yous foul works . esp. aroung ladies.. away smiling for the customers...allways have gummy bears for the kids that come in the dealership.. come to sacramento.. meet me.. you might change your mind..:):)
 

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Discussion Starter #15
,,oh yes i do have a digital camera.. i will take some photos.. let a freind of mine post them for me.. still learning how to up load the photos...did you not have to learn how to do that? or you just know, you must be all wise...peace be with you..:)
 

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Discussion Starter #16
one question .. do you sell a nice set of brake upgrade for a spider?? let say willwoods? and a vented disk? to work with it??
 

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Discussion Starter #17 (Edited)
ghnl

..i am trying my best to be frendly here.:). so please understand here.. as for wheel bearing adjustment.. can you guess how many flats from the org. bearing adjustment( you know.. wheel off the car.. adjusting as per the posts in the spider section) :confused::confused:.. the diff. in adjustment?? only 1 flat per side.:eek:. was not that much.. the bearing where a wee bit tight on the first try earlyer this week before i posted the question on how to adjust the front wheel bearings...so there was not that much diff. i really don't want my wheels to go on their merry way with out me durring a drive.:eek:. and really do not like any vibration at all , maybe like you, a nice tight spider...sorry if i seamed a wee bit hot.. but some how judges with out knowing the whole story, or being here to see the problem..not very fair..no??..in all fairness.. when ddouglas was going strange with that 135 mph spider...was i not trying to tell him to step back, take a deap breath, before he posted anymore ref. to a very fast spider..i have never judged anyone here..no less put anyone down.. judgement is not for me..it is for someone else......if you look at almost all my post.. i have had nothing but kindness and encourgment to anyone here with a question..do we not learn form questions..and mistakes???:)
 

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Discussion Starter #18
let's try this..

.. i was not the one to start this project.:eek:. go to the 'gt'65-74 fourm,:) the look for 'my cheap 4 pot caliper coversion project'.. then please if you must.. tell me that i am fool.. i did not start this project..i first saw it here .. other folks have done this.. are they any less a fool than I?are you just upset that someone found a diff. way of brake coversion, than buying a very pricey kit form some alfa part supplyer?.:confused:. all i did was ask a question.:confused:.is asking a question wrong??there is a lot of questions asked on this board..some folks here like polly bushings in there rear trailing arms..some don't .. have you judged them.:confused:.if your take on 'said' polly bushings is diff. from what you like..if i am wrong..i will admit it..never had a problem with that.:)..i will face up to it..and if need to..take my lumps for it..have you not made a mistake? tryed something that you thought might work and found out later..man that was a bad idea???:eek:i have.. and i have changed for that reason...... agian if i have offended you with an honest question.. then i am sorry for that question..but.. all it was, a question..
 

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The high road is always good.

I am not questioning your desire to 'up-grade' your brakes. I agree that it is likely an un-needed up-grade as properly functioning Alfa brakes with proper pads are very good. I can't see why you'd need 'bigger' brakes for a street car except for bragging rights.

Anyway, my concern is your wanting to have the rotors 'kick back' the pads. That is not how they are supposed to work. The caliper pistons themselves should retract enough to release the brakes. If they are not then something is wrong with the system.
 
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