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So I put new BMW 320i calipers and pads on my car.  Car has Porsche 914 front suspension and rotors.  Car now stops on a dime with less effort but unfortunately squeals brakes loudly during light braking.  No squeal without brakes and squeal disappears during hard braking.  I bought the Bosch quietcast pads but I think I really should replace the rotors at the same time.  Probably should have done this when I switched out the calipers and pads.  Is this the best way to cure squeal?  Also I've got 23,000 miles on the car.  Looks like unlike modern cars I will need to remove bearings from spindles.  I'm assuming bearings are still good at 23,000 miles.  Or should I spend the extra $40 and replace the bearings.

BTW leaves are peak in Appalachia.  My car is awesome on these roads with the new mods. 12345

Phil Luebbert


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If there are no grooves that catch finger nail when you run finger nail across rotor and it isn't blue rotors should still be good.  Rotors can be cleaned like new on a machine lath. In VA Beach do they get a light rust just sitting a day or 2?  Light rust will cause a squeal too. New rotors will need bearing races installed so, yeah, new bearings.  Big choice of rotors for 914's from cross drilled, slotted, frozen, coated.  Is it possible your new BMW pads run on unused previously surface of rotor (since they are larger)?  

Al. They are big iron calipers. 914 calipers are also iron. Even the M calipers for the late 60s 911s that will fit my car are iron. The only aluminum calipers that will fit my car (with some slight modification) were a very limited edition M caliper made by Brembo way back in the day. I've got steel wheels and big iron calipers. Still work pretty nice. 

Last edited by 550 Phil

The BMW 320i calipers give 40% more pad brake surface area (same as a 911) - for just a few ounces.  Go with drilled rotors and its probably an even weight swap.  Paint calipers red and it looks cool too.

From the Pelican article on this 914 conversion - perhaps another chamfer needed.

There is one downside to this conversion-the material on the pads is a wee bit too large (near the pins), and will wear "around" the outer edge of the rotor. One solution is to cut a taper into the edge of the pad using a rough file. If there's a pad that fits the caliper and rotor more exactly I'd like to hear about it.

Last edited by WOLFGANG

I recently did a brake upgrade on the BMW for track use, and I spoke to the folks at Turner Motorsport (BMW aftermarket) about rotors.  They said that drilled robots are mostly hype and have a tendency to crack.  Grooved rotors are actually beneficial for hot gas removal, but only for heavy track use.  Regular vented roots are more than enough for street and occasional track use.  They could have gotten more of my money but didn't advise me to spend needlessly, so I believe what they say.  Some of my more experienced track day friends echoed the same thing.

Wife's '13 MB 250C Sport came new with drilled front rotors. She'd complain if they squeaked for sure - no squeaks or issues so far.  (Argh, it also has stagger wheel size so tire rotation is out). Only reason I mention for Phil was that he likes to drive the twisty, winding, mountainous Skyline Trail near VA's Interstate 81.  A gorgeous drive when the colors change.  Brakes are important as many miles of the road have no guard rails and a significant drop off.  For some reason the twists are at higher elevation - then there is a long down hill to a small town.  Without ventilated brakes (914/VW are solid) the rotors can heat up, glow red and boil the brake fluid.  So justification for the Madness of cross drilled rotors.

Brake rotor holes or slots help air ventilation and expel heat. Rotors will run cooler and cool off faster - Stock rotor will over heat sooner and stay hot. Slots increase brake pads bite - Stock rotors do not.

IMG_2079IMG_2076IMG_2078IMG_2077Once again thanks for all the great advice. As you can see my pads are larger than rotors in front and back but particularly toward the pins. Rotors nice and smooth. Champhered  the heck out of the pads particularly where they overhang the rotors. Put the lubricant on the backs and guess what. No squeaks. And it didn't cost me a cent. I think I'll probably have to do this every once in a while as pads wear down and pads start to overhang rotors. 

Btw when I took off the wheels there was a bit of sticky stuff on the left wheel hub. Does not look like caliper is leaking. Brake fluid looks good. Maybe some axle grease?


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