squeaking brakes

[y11ngdanjr]

so i have a 95 nissan 240sx and i want to change the breaks

how do i tell if i have abs or not?

ive never really changed the brakes on a nissan before but i changed it on a honda

can u guys please tell me what i need to know to check what's wrong with my brakes and how to fix it?

how do i tell if the rotor's bad, calipers, etc

thanks

[slipnfall]

MOST ABS-equiped cars will have an ABS light in the dash that lights when you 1st start the car. If not, when you'r down there looking at your brakes, look for an electrical connector near the brakes/rear of the rotor... that's the speed sensor. If you have one(at each wheel), you have ABS. You can also look at your master cylinder: non-abs has fewer hard lines coming from it(sorry, don't know the number, search for this one).

As far as the rotors go, you can't really tell, just by looking at them,(unless they're *really* bad) if they are warped, or worn un-evenly. Get a good measurement of the rotors' surface thickness(surface, don't measure any lip around the edge), and this will tell you if you absolutely need new rotors.

You didn't mention what Honda you changed brakes on before, but more than likely it was a similar setup... it's actually very easy IMO. All you need to do is remove the lower caliper slider bolt, then loosen the top one. Knock(gently) the caliper loose with a hammer, and rotate it all upwards. Then you simply pull out your pads from both sides of the rotor. They slide in a hardware 'track': make sure you have those, along with brake shims.

Just do this for all four wheels: make note of the thickness on both fronts, and both rear pads. Make sure the wear is even along the whole pad. As long as the Left/Right sides are wearing evenly, you'r probably OK. If the pads are really worn, it's probably the wear sensor on one of the pads causing the noise... look at the pad towards the inside of the wheel-well: it'll have a metal tab that gets close to the pad contact surface. If it's even with it, that's your squeeling. Does it go away after you apply more pressure to the brakes? If so, that's likely it.

HTH, for more detailed instructions you should do yourself a favor and download a factory service manual off the 'net: they're posted everywhere, just search and you should be able to find a link. It's a large download(do it from school/work, put it onto a CD), but worth ever page. No better explaination than from the factory.

Let us know how those brakes look.-Jamie

[y11ngdanjr]

They slide in a hardware 'track': make sure you have those, along with brake shims.\

wat does that mean?

wat will happen if i dont resurface my rotors

i checked and found that my brake pad on the right front was cracked so i bot front pads

im going to change it out tomorro and i downloaded the manual online

thanks for the info

[slipnfall]

Oh, well I'm not 100% sure the '95 has what I was describing: I'm basing that off my older '92. Anyways, the 'hardware' usually consists of two or more shaped pieces of thin aluminum. They sit on the inside of the brake caliper, and wrap over the outside edge of the rotor. If you look at your brake pads, there's tabs at each end. Those tabs slide in this hardware track I'm talking about. Basically it's so the brake pads slide closer/away from the rotor, on something other than the caliper itself. Plus it helps keep the pads from shifting up/down. Also there may be another piece of aluminum that sit on the piston surface(the large round part(s) that actually pushes on the inner pad). The FSM you download should show these in an exploded diagram.

Yah, broken pads are no good. Did the car brake OK, other than the noise? Excessive heat may have caused that pad to crack, but that's nothing more than an educated guess. Run your fingeres over the surface of the rotor: feel for any deep scratches/gouges, or obvious surface irregularities. Look for any major discoloration on the surface(heat induced).

If they out of round it'll just wear the pads quicker/unevenly. Front rotor warpage can cause vibration in the steering when braking also. This was how I knew my Honda rotors were warped(just got new tires and alignment).

-Jamie

[slipnfall]

Oh, forgot: the shims may have come with the new brake pads. They just go on the back-side of the pads. You can use your old ones if they didn't come w/new ones.

Now would be the time to get some brake caliper grease too: comes in ketchup-style packs at the auto store, real cheap. Put this on any sliding/contact surface(NOT between pad and rotor, keep it off there!). Use sparingly everywhere else and it'll not only keep everything lubed up, but reduce noise also.

[y11ngdanjr]

there looks like there r some deep scratches in the rotor....so maybe itz a good idea to resurface them....

yea ill b sure to go get the grease tomorro....

i wish i had a caliper to measure how wide the rotor was

i looked at the bad break pads and they dont look that worn down i think

86 bux for pads from the dealer....damn i wouldnt have bought them from the dealer but there was nowhere else close by and i dint want kragens ****

ok thanks for the info

do u think ill need to bleed the brakes?

how do i do it on a 240?

[slipnfall]

Yeah just ask whoever you bring them to if it's worth re-surfacing them. If you'll only get one more 'cycle' of use out of them, it might be worth your while to just buy new ones... they're not all that expensive: maybe 15-20 each. This just depends how long you plan to keep the car. Call around for prices...

Yeah that's more than I'd pay for pads, but you usually get your money's worth when buying from a dealer(usually).

You won't need to disconnect the brake lines to do pads/rotors, so don't. So no need to bleed them. Just hang the calipers from the springs w/something(wire) to keep tension off the brake line while you work on the rotors.

[BadMojo]

there looks like there r some deep scratches in the rotor....so maybe itz a good idea to resurface them....

yea ill b sure to go get the grease tomorro....

i wish i had a caliper to measure how wide the rotor was

i looked at the bad break pads and they dont look that worn down i think

86 bux for pads from the dealer....damn i wouldnt have bought them from the dealer but there was nowhere else close by and i dint want kragens ****

ok thanks for the info

do u think ill need to bleed the brakes?

how do i do it on a 240?

It may well be quicker and easier to just get some new rotors from somewhere like Autozone. I got some Brembo rotors from NOPI, but even something from Autozone would be better than some beat old rotors. It might even be more cost effective and take less time than having the other ones turned.

Your not going to be letting any air in to the system, so I don't see why you'd have to bleed your brakes now. It might not be a bad idea to change your fluid, but I'd do that later.

Pick up the caliper grease (the permatex stuff was nasty green) and maybe even some of that blue Disc Brake Quiet stuff to use between the pad and the shim if it's not already glued on there (I don't think it is on the OE pads). There should be shims and shim covers if I remember correctly.

While it's technically not proper to reuse the aluminum hardware, I know a lot of people do it as long as the old pieces are in good shape.

I'd recommend dl-ing a Factory Service Manual before you do this job. It'll make it a lot easier for you.

[y11ngdanjr]

can u explain what the reason is for hanging the calipers on the springs? how does that prevent pressure from being put onto the brake line?

my friend told me cross drilled rotors rnt as good because they r for racing rather than everyday driving

i donno i thot they would cool down faster in general

[BadMojo]

can u explain what the reason is for hanging the calipers on the springs? how does that prevent pressure from being put onto the brake line?

my friend told me cross drilled rotors rnt as good because they r for racing rather than everyday driving

i donno i thot they would cool down faster in general

You can hang the caliper from the spring using a bit of coat hanger. The caliper is iron and heavy, it's really not good to have it's weight supported by the rubber brake lines and fragile hard lines.

Cross drilled rotors should be fine as long as they are a quality rotor that's been machined properly. Some times, a company will take an non-cross drilled rotor and then drill it. Problem is, they don't always do it properly and can weaken the structure of the rotor.

Personally, if I were going to go with something other than a plane old OE style rotor, I'd get a slotted one before cross drilled.

Either way, the main benefits are that a slotted rotor will allow gasses produced by *very* hot brake pads to escape (through the holes or the slots). Slots or holes are also supposed to increase wet weather braking performance.

Honestly, it's up to you if a cross drilled or slotted rotor is worth the money. Unless you drive really hard with lots of heavy braking, de-gassing the pads won't be an issue. I'm also not convinced the wet weather performance benefits are that huge either. I'd imagine that you'd easily lock the tires up before the brakes would suffer from wet rotors.

As for cooling, cross drilling when properly done on a vented rotor (like on the front of a 240SX, the rear rotors are solid) can help. Again, you'd have to be driving pretty hard for this to be an issue.

I've got Brembo rotors, Hawk HPS pads and ATE Super Blue brake fluid and I've yet to experience any brake fade. I don't track my car since it's my daily driver so all of my driving is on the street.

This is just my opinion, but it seems like a lot of people get cross drilled or slotted rotors just for the looks.

[slipnfall]

Thanks for helpin' me out there mojo...Personally I think that, appearance asside, brembo blanks(no cross or drilled), a good pad(I like the semi-ceramic ones, b/c they're extremely low on dust), stainless brake lines, and maybe a good fluid flush/replacement will yield performance that anyone will be happy with for street driving. Like you said they may not last you 30 rounds of a track, but for a daily-driver, it's far better than stock.