Brake issues

[jukon]

Hi all,

So I've been having some noise/pulsing on my brakes lately. Lots of noise comes from the passenger rear when I brake, the pedal pulsates and lately the steering wheel shakes as well. I bought new pads for the rear and lubed the caliper sliders hoping this might solve my issue but it hasn't. Since the noise has actually gotten worse after I've replaced the pads I'm wondering if I've done something wrong. Is there something I should check or do before replacing the rotor? Things are pretty badly rusted back there and I'm hoping I wont need to change the caliper as well, even the thought of trying to get the caliper off to change the rotor gives me a PITA. Any suggestions?

Also can someone please confirm if there are supposed to be "M-clips" on the rear because when I replaced the pads on there weren't any. I remember this being annoying when I did the front pads.

Thanks!

 

[ap123]

Shaky steering wheel under braking is normally caused by warped rotors. sounds like thats the cause of your issues.

 

[MaxPower]

Make sure the parking brake is adjusted properly on the caliper. It is adjusted using a screw under a bolt on the caliper. If it's not adjusted properly, it will drag.

 

[MaxPower]

Also, an inexpensive rotor is only $25-50 and the caliper is only held on by 2 14mm bolts that are generally easy to remove.

 

[rit14623]

Yes, M clips are supposed to be on both front and rear brake pads.

 

[Installshield 2]

if its shaking the wheel, the problem is probably with the front brakes...not the rear...but yes, as mentioned, both front and rear should have 'retainer' clips installed in the caliper when you put the pads in place. Without them, they'll vibrate and walk all over the place, and possibly crack the plate or caliper mounts...

If you're unaware of when it was done, if ever...i'd suggest a full brake bleed with fresh pads and rotors on every corner to see where you're at...I didn't bleed my system until i hit about 155,000 miles...and the s*** that came out of there was as dark as black coffee...Mine was so bad my front brakes were barely squeezing at all (i noticed the issue mostly because rear pad life was only a few months, yet the fronts had been unchanged for nearly a year)...which was mostly due to some air eventually getting in...but if bleeding to remove air, might as well just buy 2 quarts of good brake fluid and flush it all out...

 

[tweety2300]

By m clip do y'all mean the one that holds the pads in the caliper bracket or the weird looking wire handle thing that attaches both pads to each other

Max power what you're referring to is the adjustment of the piston on the caliper which has to be done to get the new pads on, it does not adjust the e brake

 

[jukon]

Thanks all. I replaced the rotor today, as you said it was actually pretty easy since it's just two bolts. They were pretty on pretty tight though and I was praying that the bolt wouldn't snap. The major noise from the rear and majority of the pulsing has stopped. As I had stated the steering wheel shakes a little, fixing the rear rotor obviously wouldn't help that. I think I have to replace one in the front pretty soon.

 

[weitrhino]

Anyone know a source for the brake pad guide plates? I have a broken one on the RR allowing the inside pad to knock around till pressure is applied. It's noisy. I haven't found an individual part number for them in the parts manual. It's part #8 in the diagram.

http://s283.photobucket.com/user/weitrhino/media/P5RearBrakes_zps8b47e7e2.jpg.html?sort=3&o=0

(The link works but I had to refresh the page to see the image.)

 

[tweety2300]

Autozone and advance has them

 

[sleepwalker]

^this. Go in and ask for a "brake caliper hardware kit". Should have all the clips and springs and such that you need, for both rear (or front) wheels. I'm about 99.7% certain you won't find just one of the metal clips, but it ought to be pretty cheap for the whole kit, and if you've got the wheel off anyway, might as well replace the rest of the pieces.

 

[weitrhino]

Thanks guys. I'll check into it.

 

[jukon]

Hey all.

So I now have new pads and rotors on the back. Driven with them for a while now and the noise has come back. I'm not sure what's going on. When I brake hard there is a lot of vibration in the back and my hatch vibrates loudly. I put the car up the other day to take a look and the rear driver side rotated freely with the parking brake on. I will need to adjust that it seems. I'm wondering what else could be wrong because the rotors were in terrible shape in the back really rusted out.

 

[Installshield 2]

Sounds like a seized caliper on the rear...its pretty much impossible to have the parking brake to the point where a wheel moves freely by hand (it may roll on a hill, but still very hard to rotate by hand)...which would point to the piston in one of the rear calipers simply no longer moving...

That doesn't explain the vibration though, at least not directly...do you have uneven pad wear? and have you ever serviced the brake fluid? that stuff isn't permanent, it absorbs water over time which will cause corrosion in the brake system...wouldn't be a bad idea for a complete flush...

 

[jukon]

Sounds like a seized caliper on the rear...its pretty much impossible to have the parking brake to the point where a wheel moves freely by hand (it may roll on a hill, but still very hard to rotate by hand)...which would point to the piston in one of the rear calipers simply no longer moving...

That doesn't explain the vibration though, at least not directly...do you have uneven pad wear? and have you ever serviced the brake fluid? that stuff isn't permanent, it absorbs water over time which will cause corrosion in the brake system...wouldn't be a bad idea for a complete flush...

Yeah definitely thinking about flushing the brake fluid. The brake rotors I picked up seem to have some rust on them already. That could be the cause of vibration no?

 

[P-Funk!]

No, but if the rust is on the swept part of the rotor - the caliper is bad, or very badly out of adjustment. The new rotors 'could' be warped again - not impossible (just unlikely if everything is in proper shape)...

 

[jukon]

What do you mean very badly out of adjustment?

 

[Installshield 2]

Yeah definitely thinking about flushing the brake fluid. The brake rotors I picked up seem to have some rust on them already. That could be the cause of vibration no?

Most aftermarket replacement rotors for these cars are straight up cast iron, or with more performance oriented rotors a very high carbon content steel (ceramic rotors won't show up until you dropped $5000+)...they're often sprayed with a protective coating of oil, and wrapped in plastic to prevent rust from forming during shipping...but as soon as they're exposed to even slight humidity, they'll begin to surface rust...100% normal, and that shouldn't cause any vibration or anything...the pads will scrape that rust off every time you press the pedal...

vibration under braking can be caused by a number of things, and even multiple different things happening together...bad wheel bearings, a bent caliper hanger, seized piston on one side and not the other, water in the brake lines (which can cause pedal pulsing as the water quickly boils, it'll feel kind of like an ABS system), etc...even poor alignment can show up more noticeably under braking...

 

[jukon]

Any ideas on things I should check/inspect before I start buying replacement parts?

I plan to at least bleed the brakes possible flush the system, adjust the parking brake, and inspect all sides including testing the grab and possible warping.

If I have a seized caliper how can I diagnose it? If it's seized and the tire spins, pressing the pedal won't stop the spin right? I will also try to diagnose the ABS sensors.

 

[pcb]

Any ideas on things I should check/inspect before I start buying replacement parts?

Check your P-Brake cable for being seized. The P-Brake connection point on the rear caliper needs to rotate back and forth as the brake handle is pulled. If that connection point isn't rotating, then your rear caliper is not self adjusting. Your caliper may not be seized but the piston may not be adjusted properly due to the seized cable.

http://www.mazdas247.com/forum/show...etting-stuck&p=6043634&viewfull=1#post6043634

I plan to at least bleed the brakes possible flush the system, adjust the parking brake, and inspect all sides including testing the grab and possible warping.

Get yourself a turkey baster at a dollar store and use it to suck the old brake fluid out of the brake reservoir then refill it with new fluid before the brake bleeding process. A brake fluid flush is the same procedure as a brake bleed. Bleed each brake until the fluid comes out clear.

Don't forget to do the clutch,.. I did it from the top and didn't need to remove anything.

This is the dust cap covering the bleeder screw:

If I have a seized caliper how can I diagnose it? If it's seized and the tire spins, pressing the pedal won't stop the spin right? I will also try to diagnose the ABS sensors.

If you have a bad ABS sensor, you will almost certainly have your ABS or red brake light on the dash come on.

If the calipers piston is seized, there will almost always be enough brake pedal pressure to apply the brake,.. but the seized piston won't back off so the brakes will drag.
Same with the rear P-Brake cable. If you pull hard enough to get the rear cable moved,... it will stay applied after the brake lever is released and drag that brake.


I notice that right after a rain, my rotors are all rusted and will pulsate for the first few times I hit the brakes. That thin layer of rust is worn off with a few applications of the brakes.

If your car has been sitting for a while and the area between the pads and rotor stayed wet long enough then the rust can eat into that surface and make a thin spot creating a pulsation in the brakes.

I just drove my car 2 hours before this picture,... then it rained. (the caliper is 1 week old ??)

Clean the mating surfaces of all your wheels and hubs. Try to clean the surface between the hub and rotor as well. A bit of anti-seize or grease will help stop the rust and help to get the wheels off when you need to. I had to buy a sledge hammer to smack my wheels to get them to break free from the hub (rotor). If the wheels aren't mated flush with the hubs it can misalign the rotors and calipers creating a pulsation.

Make sure you tighten your lug nuts following the proper procedure so the wheels mate with the hubs flush.