Front Brake "springs" sound when I push it, easy fix?

[CanuckQx4]

I noticed today on the hottest day of the year, when I depress the brake, my driver front side makes a "springy" stretching kinda weird noise. Does it when the car is parked and while driving.

It only makes the noise while youre depressing the brake, not while its releasing or anything.

I made a video that would probly help alot but Im having trouble uploading.

EDIT: Heres the video



What do you guys think could make that noise???

[CanuckQx4]

added video, skip to 15 seconds in

[patqx4]

if it were me the first thing I'd do is take the sliders out and regrease them, also visually inspecting the entire caliper, pads and shims for any irregularities.

[CanuckQx4]

slider?? What is that, Ive never heard that in a brake reference before

[patqx4]

Have you changed brake pads before? Under the two fasteners that hold the caliper to the caliper bracket, there are sliding pins that pull out. Look for the 2 rubber boots, they pull out of them.

[m0nkeyprince]

i agree with slider regreasing, its kinda a pain though, you have to take out the caliper bracket held on by 2 giant bolts

[CanuckQx4]

Yes Ive changed the pads on this car before, just dont recall any rubber pieces or pins. I guess Ill just take the caliper off and pads out and see what can be lubed.

Thought the problem might be more involved than that though, its a damn weird noise

[patqx4]

You don't need to remove the big bracket bolts, It's very unlikely the bracket has anything to do with this. Simply remove the two caliper bolts (12mm I believe) and lift the caliper off the bracket and pads, I like to hang it off the bottom spring coil, then just pull out the sliders. You can use a flathead screwdriver to clean the old grease out, being careful not to damage the rubber boot, before regreasing. Maybe someone else can say what kind of grease is best all I know is the stuff I use says "caliper grease".

[Pathy415]

Check to make sure nothing is broken/cracked. I got into a minor fender bender in another car and it started making a similar squeaking noise. When I pulled the wheel off I noticed that I cracked my caliper mounting bracket.

Check everything, you rely on your brakes to stop so I'd be very thorough in your inspection.

[CanuckQx4]

Do you have to grease the brake calipers?? I noticed a zerk fitting on the caliper that I didnt notice when I did the brakes.

I lubed up the locating tabs on the calipers but it didnt help

I figure the caliper may need to be greased?? The inner brake pad was very rusty on its backside, like amazingly rusty.

Im curious if the brakes need greasing, and maybe a special grease be used?

[CanuckQx4]

now im thinking I may have just noticed the brake bleeding nipple and not a grease zerk at all

stupid me

[ARKQX33V6]

Canuck
Besides the sliders, which are greased, it is hard to tell where the noise is coming from. Are you sure it is coming from the wheel brake assembly? If yes.

Break down the complete disc brake assemble, and support the caliper by tying it to the springs, caution with the brake hose do not twist it.

When tied to the spring and facing so you can work on it, disassemble, remove all parts leave the pistons alone, do not press the brake pedal.

Clean all parts using brake fluid, check the pistons around the rubbers and clean out the seat area with a pointed tool, use caution not to scratch the metal and not to break the rubber. Push the pistons back into their cylinders, if pads are parallel, lots of meat left, clean and deburr the edges, Slight lubrication on the rear and clips and anti rattle spring. That anti rattle spring must be free or do not use.

Lubricate the shoulder bolts and check rubbers for rips, assemble.

Check the rotor for parallel, run out and unevenness. Use a straight edge check the rusted areas are not higher than the smooth pad area, if higher, take a flat bastard file and clean up the rust.

Now clean the rotor and the pads surfaces with brake cleaner, reassemble.

That squeak sound could be your piston acting on the vacuum booster, acting on the master brake cylinder but I need you to pin point where that sound is coming from.

When working on brakes be very clean especially when inside the hydraulics.

Brake rotors do flex when worn, check your rotors for width as per the book. A compressed air supply will assist with the rust.

[CanuckQx4]

Thanks for that writeup, very informative

One thing I noticed in your last post is how you said my rotors could flex when worn

Just before I took the caliper off I started the car and had my sister pump the pedal, I could notice when she pumped it that the rotor itself appeared to be flexing.

I didnt think that was a bad thing as it was only flexing 1/8" or so

Could that be a huge problem??

Im looking into EBC pads at the moment, and probably some new rotors that Im undecided on

[ARKQX33V6]

Rotor flex is really noticeable on Chrysler mini vans, you can hear it at a stop lights. But mini vans are not QX4 or Pathfinders, Nissans are of a more substantial in rotor width. If your rotor is flexing, make sure the pads squeeze equally side to side. That can be done by taking them out and looking carefully to see the left = the right in thickness and be sure they wear in a parallel fashion. Clean and lube the pistons and keep clean.

With the pads off, the caliper off, measure the width of the rotor across the friction cleaned shiny area. If there is a build up of rusted rotor, that rusted material has a greater propensity to get squeezed when braking and cause squashing of the rotor. A clean file will remove it but it takes a bit of time.

Next look at the centre of the web of the rotor, the castings of the web. Check them all for deterioration. Blow out the rust with compressed air.

The type of brake material will cause rubbing of course with different sounds, but ceramic brakes are nice and keep the rotor sharply clean, but the raised rotor with the rusted area will cause the brakes to rise and fall as the rotor turns causing pulsations in the foot pedal.

The rotor must be kept clean, grease, brake dust and road dirt will cause squeaking, and a noisy brake.

Pads that are scored and thus have leading edges must be cleaned and undercutting the lead edge makes for a quieter brake.

The same goes for the rear shoes which seem to last forever as long as you sand them down to remove that shiny glaze, keep the leading edge undercut and clean them at least 2x a year.

The E brake must be kept tight about 5-6 notches, greased cable and if the drums can be removed with no difficulty the brakes are set too low.

The fronts do about 80% of the braking but all brakes, surfaces, drums, rotors must be kept clean. With bad rears the fronts are over worked. With bad fronts the braking effect is minimal, with all in good shape that 4200 lb vehicle can be easily stopped without alarming the hood.

[CanuckQx4]

This noise is pissing me off so much Im contemplating just replacing the pads and rotors to see if it fixes it.

The noise in that video happens all day long in parking lots and at stop and go traffic, so annoying.

I just dont want to replace the pads and rotors when I think they have plenthy of life left and then still have that noise there

What the heck would cause that noise??????? Seems pretty unique was hoping to pinpoint it.



I wasnt to impressed with the rust on the caliper pistons either

[ARKQX33V6]

If you are that pissed, take the calipers off the car both sides unless you know what side is noisy but if both are noisy then both calipers off. Both hanging on the srings carefully with both sides having the brake pads installed. Then with the correct sized piece of wood taking the place of the rotor jammed in and secured to not allow the pistons to be pushed out, with a helper to listen brake down on the brake pedal and liston.

Does it still make the same noise...now within the caliper or does the noise come from the master cylinder?

Does the noise stop...the problem is within the rotor assembly.

You should be able to determine where the noise is emanating from.

Take your time, use another pair of ears.

From your picture of the pistons, they are due for a cleaning and lube, also the OD of the pistons must be clean and grime free. When you dis-assemble the brakes as above it will give you 2 separate areas to search.

The brake pedal and booster vacuum can also make noise so have your second set of ears made aware.

With 4 ears listening this should be solved, let us know!