Brake problems

[260zjade]

i searched the forum and i couldnt find help...maybe someone has a link...anyway

 

so i took my car to the shop to replace my brake system and make everything run smooth...i have an ear splitting squeel everytime i apply the brakes...they put new rotors on once, then replaced the pad when the squeeling started (didnt squeel before they touched it)...this time they told me the squeel is a trademark of the z braking system and that they cant do anything to fix it (like replace the rotor that has the gouge they put in it)...so i decided im gonna redo the brakes myself...does anyone have any suggestions on systems (rotors, pads, etc.) for a modified stock car? i like to race around everynow and again, but i dont need self cooling calipers or anything...thinking about slotted rotors though, and a rear disc conversion... any suggestions, advice, warnings would be great! thanks!

[JMortensen]

Clean the caliper where the pad hits with an old toothbrush. Get all the dust out of there. Then put a LIGHT coat of synthetic brake grease on the back of the pad where the piston hits it and also on the edges where the pad contacts the caliper. You might also chamfer the leading edge of the pad while you're in there.

 

That should solve the squeak.

[260zjade]

im gonna tear into those breaks for the first time ever soon...so i may be back with some more questions, but i will definetly try that! thanx for the tip

[Chino 240Z]

If they were stock brakes, check to see if there is brake / pad shims on the back of the pads. Someone may have forgot to reinstall or didn't see them on the old pads and tossed them. New brake shim kits are avail. from MSA for around $20 if I remember right. Includes new pins and clips too. I had same problem with the old stock front brake system... shims were missing. That was an insane squeal. Brake grease and chamfer the leading edge of the pads is always done here too. Good luck.

[Dtsnlvrs]

I have never used the grease, just the factory supplied shims. Always use a good street pad like a KVR or Axxis Metal Master and they will not squeal. If you install "Auto-X" or "Race" pads they will squeal alot. Since I brought up pads, ones I Like/Love: Axxis Metal Master and KVR, Axxis is a little dusty but a very time proven compound (circa 80's) and is not too harsh on the rotor, KVR is like butter to the rotor.

 

Pads I dont like some hate: Hawk (any of them) too agressive for street use, even their "street" pad will eat rotors like I eat pizza, Porterfield chunked several sets auto-xing, EBC greenstuff (see note on Hawk).

 

As far as fluid goes, non full out race car, use Castrol LMA

[Chino 240Z]

Never had squeal using race pads once shims installed with stock calipers. For track car used Porterfields R4 compound for many years. 5 hrs per event, never chunked, and were easy on the rotor. Be sure to bed pads in properly per mfg instructions. I have screwed that process up once and messed up some new pads. Good idea to consider a street pads that will warm up quick to working specs for daily driver. Race pads need to heat up to to temp to start stopping properly, or they may give you a big surprize in street traffic.

 

Slotted rotors are weak but would probably be fine for normal street use. We put 3 years of track events on a set of stock solid rotors and never had issues, they were just having to work too hard. Recently jumped to the Arizona extra thick 12.2" rotors, Wilwood calipers & race pads for the track.... just did event at Calif speedway and these things are incredible! (but so was the price too..yikes)

[bjhines]

The shims get crushed to death after a few years. Many auto-parts stores sell slightly different shims than the factory used. Get the Nissan Shim kit and all will be quiet.

 

I dont use the shims at all to keep it simple on track. The brakes will squeal like hell without the factory anti squeal shims.

 

I prefer NOT to use slotted+/drilled rotors on track. I would never spend the extra money on bling rotors for a street driven car. Slots and holes are primarily a bling factor thing. They look good if you have wheels to show them off.

 

A rear disk conversion can be a great thing indeed. I would go for the Modern Motorsports rear disk kit. It is track tested and a significant improvement over stock drums in every way. One thing to consider is that the rear disk kit was intended to work with the front Vented disk conversion with the Toyota 4 piston calipers. You might consider doing both the front and rears as a set to ensure a balanced braking system.

If you intend to only change the rear disks, then you might consider a different conversion that uses a smaller rear disk(like the 280ZX caliper and smaller disk kits).

[Guest Mberglo]

Hey, I want self-cooling calipers. Do they still make them with R12, or do you have to convert to R134?

[9t4ss]

Another thing to do is after having the rotors turned, have the machinist put a non-directional pattern on the rotor face. Basicaly putting a scuff pad on a die grinder and lightly run it across the rotor surface. This will break up the harmonics of the squealing, and some good pads.

 

Alan