BRAKES ====== See also the archive files: Repco_MetalMasters, Rear_Brakes_Tool, Solid_Shifter, Adjust_Linkages, and faq.vw.perf Q: What brakes do VWs come with? (Note the dates are +/- 1 yr). A: Pre-80: Fronts= (A1) Teves or Girling discs (early Euro had drums as well) Rears = (A1) drums, non-self adjusting Post-80: Fronts= (A1/A2) Kelsey Hayes ("Banana pads"): Sciroccos 8V, GTIs 8V Girling: 16V Sciroccos, >90 Passats & Corrados Non-vented rotors on most initially, vented for higher end cars. Rotor diameter increased over the years. ATE: Wolfsburg-built GLIs 8V Rears = (A1/A2) self adjusting drums Teves disc (high end) Girling: Wolfsburg-built GLIs 8V General: Later cars have brake proportioning valves, several types used, some are with the master cylinder (e.g., 84S) others are in front of the rear axle beam on the left hand side. Front Vented Rotor Sizes: 239 mm (9.4") A1/A2 models 256 mm (10.1") 280 mm (11" 4 hole, 6 hole for VR6) Corrados, Passats Rear Solid Rotor Size: 226 mm (9.0") For 14" wheels, you can go up to 10.1" rotors (and the matching calipers). For 13" wheels, 9.4" rotors is your max. If you want the 11" rotors of the corrado, then you need 15" wheels! :-) See also Brake_Upgrades Q: I need to change my brake pads, which should I get? A: This is a tricky question, and depends on what car you drive and whether you were happy with what you had. Normal driving, no problem with fade: Stock VW, or Mintex Silver pads. Repco Semi-Metallic are ok as well. Others like or prefer Wagner Pads. Autocross: Repco Metal Masters. Be aware that many have reported that these pads require significant more pedal pressure, especially when cold. Advantages: Fade resistant, less brake dust, no squeal. Q: Is it easy to change pads/shoes? A: On most newer VWs, changing front pads is next to trivial. Rear pads require more work because the piston needs to be screwed in which is either done with a allen (hex) wrench or a special tool. Rear shoes (drums) are probably the hardest, but still easy enough. Follow Bentley and/or Muir. Q: Do I need to turn my rotors each time I change pads? A: Another religious issue... In general: NO, unless your rotors are badly scored. If they are warped, replace (it's cheap and easy to do). Call places like APS & WolfSport. Note: If you take the rotors off yourself, turning them at a machine shop costs very little. Q: How often should I bleed my brakes and change the fluid? A: Brake fluid should be changed AT LEAST every two years. Bleeding should be done yearly and after an Autocross. Brake fluid absorbs water which corrodes the lines. Bleeding regularly will significantly increase safety and life of your brake components. DOT 4 fluids have a higher boiling point than DOT 3 fluid but are also more hydrophilic and therefore must be replaced more frequently than DOT 3. Q: What brake fluid should I use? A: Check the manual. Most older VWs use DOT 3. The newer ones use DOT 4 or Super DOT 4 (higher boiling point). Castrol makes one which is both DOT 3 and 4 compatible with a very high boiling point. The only place I have found Super DOT 4 in the US is at the VW dealer. One of the dealerships here also recommends Wagner as an aftermarket DOT 4 oil. The higher the boiling the better: Brake -> heat -> fluid boils -> bubbles -> loss in brake pressure -> crash. Q: How do I remove the screw that holds the front rotor in place? A: If a screwdriver & liquid wrench does not work, try an impact screwdriver. It's a screwdriver that makes a 1/4 turn when hit by a hammer. Tip: When changing the rotors, make sure you put a bundle of anti-seize on the inside of the new rotors so they do not get stuck to the hub. Also remove as much rust and gunk so that the rotors seat well. I had to take mine off the hard way: Heat until red, cool with cold water, hammer and use a pry bar. Also make sure you antiseize the screw that holds the rotor in place. If the head is messed up you can try reslotting, but chances are it won't help either. If the screw head is messed up be extremely careful with those easy-offs/ screw or tap extractors. When they break, you cannot get them out. Andy's recommendation is to drill out the screw with the right diameter drill instead, rethread, and put in a new screw of a larger diameter. You don't want to make the hole too big either, though you could use a thread- locker to come back to the original size. Note that that screw is not vital! It only holds the rotor temporarily in place until the wheel bolts torque the rim/rotor/hub sandwich together. Q: I hear a "clunk" each time I brake/start? A: Check whether all the anti-rattle springs are still there (two per caliper). Q: How do I prevent my brakes from squealing? A: Chances are that you have the original semi-metallic VW brakes pads, which are notorious for this. First line of defense is to get that "anti-brake-squeal goo" (comes in a tube or a spray can) and apply it to the BACKS of all your pads. That stuff is essentially liquid high temp rubber that will dampen vibrations. [From Jens]: Two official methods. If your car has old style brakes (A1), simply apply some copper grease to the back side of the pads. For the new calipers as in A2, this method is forbidden by VW (do not know why). But VW sells stickers you can apply to the back side of the pads, although it may be necessary to drive a few hundred miles before applying them in order to make the pads smaller. A new pad with a sticker on its back side is normally to thick to fit into the caliper. [From Jan]: The stickers he is referring to is the same as the anti squeal "goo" you can buy, just in a different form. The second line of defense is to change to a different brake pad brand. See the Repco_MetalMasters file on this subject. (In short, do not get Repco MM's unless you want to race, their Semi- Metallics are closer to stock in brake feel, while someone else recommends Wagner pads.) Q: When standing on the brake pedal, my foot slowly sinks to the floor? What's wrong? A: You either have a leak or your master cylinder is shot. Don't bother trying to rebuild the master cylinder, unless you have access to high precision tools. Mexican made replacements tend not to last long. Get the German OEM ones or the VW one (same thing, more $$$$). Q: Problems with rear drum brake lock up? A: This can have many causes: - Out of round drums. Have them turned or replaced (easy, cheap) - Change shoes - Out of adjustment or self adjusting mechanism not functioning right - Handbrake cable out of adjustment - Proportioning valve out of adjustment or faulty - Incorrect cylinders installed (17mm vs 14 mm, they look very similar but make a 40% in brake pressure!) - Faulty master cylinder. Q: What grease should I use on the rear axles of my VW. A: A high quality Lithium based grease with Molibdenum disulfide (MoS2) (all VW shops have switched to this). In general you can use "Moly-Slip" grease where you used to use the old "White Lithium" grease. MoS2 works a bit like graphite in that it doubles the lubrication properties of the base grease. Note: Generally do not mix greases of different base, e.g., an Aluminum based grease with Lithium base. They may react and lose lubrication properties. Note2: CV Joints use a special grease, less viscous grease.