Rear Brake noise.

[fl4031003]

2000 model with 75k. All stock using OEM pads. I changed the original pads (making noise at 60K with OEM pads. These pads still mad a load squeal like they were worn out. I replaced them again with OEM pads at 69K and had rotors turned. This helped for about 2 weeks and now they are squealing again!!!! Looking for answers please help!

 

[jp213a]

2000 model with 75k. All stock using OEM pads. I changed the original pads (making noise at 60K with OEM pads. These pads still made a load squeal like they were worn out. I replaced them again with OEM pads at 69K and had rotors turned. This helped for about 2 weeks and now they are squealing again!!!! Looking for answers please help!

According to the FSM, the anti-squeal shims must be replaced with the pads and disc brake grease is to be applied to both sides of the inner shims (the slotted shims). The part number for a shim kit is 04946-60031. I don't recall if new shims came with the brake pads (part no. 04466-60070) or were separate. The pad support clips can be re-used if not sprung (part no. 04948-60010).

 

[fl4031003]

OEM pads

I do not recall if the shims were replaced? What goes wrong with them?

 

[jditom]

I do not recall if the shims were replaced? What goes wrong with them?

My FSM states that if they are in good shape they can be reused.
But they should be greesed using brake greese. Cheep at Autozone.
But if you want to replace them they cost about the same as pads

 

[jp213a]

I do not recall if the shims were replaced? What goes wrong with them?

The following from: http://www.forparts.com/ICdiscbrakeproblems10.05.htm

Disc brake squeal occurs due to a high-frequency vibration between the brake pad and rotor. Following correct pad mounting procedures can prevent the majority of brake squeal.

When installing the pads, it's important to use new mounting hardware. Most mounting hardware is made from soft materials like rubber or spring steel, which is designed to acoustically insulate the caliper from the mounting bracket and wheel spindle. These parts lose their soundproofing qualities as they age.

Second, the caliper guide pins or slides must be cleaned and lubricated with a recommended high-temperature brake part lubricant to prevent corrosion or sticking. Free-floating calipers relieve the tendency of pads to rub or bind against the brake rotor and, thus, reduce noise.

Pad shims must be reinstalled if they were originally used. Too often, these shims are discarded with the old pads while the brake tech unwittingly installs the new pads - minus the required shims.

To prevent shim loss, many manufacturers are now attaching adhesive shims to the backing plates of the new pads. Other pads require clip-on shims. It's important not to attach clip-on shims to the backing plate with an adhesive noise-silencing compound. Adhesive destroys the noise-insulating properties of the shim. In many cases, manufacturers actually recommend that these shims be lubricated with high-temperature silicone grease. Last, many pads are made with mounting tabs designed to hold the pad tightly in the caliper. Taking the time to crimp these tabs into the caliper will reduce the possibility of pad vibration and brake squeal.

Note: The 2002 FSM calls for replacing the shims. From other post, it appears early manuals didn't call for replacement. For the 2000 LC, a Toyota rear shim kit retails for $32.75 and wholesales for $26.20.

 

[Jim_Chow]

My 03 LX FSM also says to replace the shims when installing new pads and to apply disc brake grease as mentioned in the other post. I asked CDan about this when ordering new rear pads and he said you can reuse them if in good condition (i.e., not corroded from road salt, etc.). Of course, you won't know what condition they're in until you pull the old shims off and look, and if you've gone this far, it's no more work to slap in a new set of shims.

 

[Tinkerer]

When I did my rears, the shims appeared OK at first, but then one assy fell apart in manual handling - it evidently had cracks in the thin sections that caused it to break apart when I removed it from the pad backing.

So, shims may appear OK but may actually be degraded nonetheless.

I replaced shims and used correct brake pad grease (with new OEM pads and rotors), and my rear brakes do not squeal.

 

[fl4031003]

Thanks for the insight

When you say "brake pad grease" is this the same as the red anti-squeal stuff you get at Auto Zone? If anyone can shoot me a blow up of the way the shims go bach together, just to make sure I am doing it right. (from the FSM) That would help alot. Thanks I am going to get new shims just as soon as I get back from Tahoe next week.

 

[jp213a]

When you say "brake pad grease" is this the same as the red anti-squeal stuff you get at Auto Zone? If anyone can shoot me a blow up of the way the shims go bach together, That would help alot.

I used Sta-Lube Brake Caliper synthetic grease by CRC (part no. SL3301). It contains molybdenum disulfide, graphite, and Teflon to resist the high temperatures. Any similar hi-temp synthetic grease should work. Put some on the slide pins too. Behind each pad, there is a slotted metal shim and a solid metal shim. The slotted shim receives a thin coat of grease on both sides and goes against the back of the pad.

I hope whoever turned your rotors did a good job. I gave up on having rotors turned years ago due to repeating problems from poor workmanship and poor equipment. I re-use them until they warp (check with dial indicator) or wear down to minimum thickness (check with micrometer) and then buy new.

 

[Tinkerer]

When you say "brake pad grease" is this the same as the red anti-squeal stuff you get at Auto Zone? If anyone can shoot me a blow up of the way the shims go bach together, just to make sure I am doing it right. (from the FSM) That would help alot. Thanks I am going to get new shims just as soon as I get back from Tahoe next week.

IIRC, the Toyota OEM replacement shims came with a small grease pack. (And well they should, for the cost...)

 

[jp213a]

If anyone can shoot me a blow up of the way the shims go bach together, just to make sure I am doing it right. (from the FSM) That would help alot.

Following from the 2002 UZJ100 series FSM (note reference to Disc Brake Grease in lower left corner and arrows on inner shims):

Here's an exploded view parts diagram:
http://www.trademotion.com/partloca...2000&graphicID=8415605&callout=19&catalogid=2

 

[fl4031003]

Cool!

Thanks for everyones quick help. I now know I put then in right. I will get the new shims and use the gease provided.