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Discussion Starter · #1 ·
Ok, guys. I'm stumped on this one and thought I'd check here before shelling out more $$ on yet another issue. My last set of pads started squealing, so I replaced with ceramic pads and new rotors. Install went well and took no time at all. Drove as normal, making long gradual stops during run-in. All was well for about 2 months, then they started squealing (not from the wear indicator either). I removed the calipers and pads, applied brake lube to the mounting tabs of the pads and even a light film on the back of each inner pad. Worked for a few weeks and squealing came back.

Now I randomly hear a grinding coming from the LF wheel. Took the wheel off and checked the pads and rotor. Pads are just below 50% and rotor looks great. Caliper guide pins are lubed and moving well. Tie rods are tight, sway bar links are tight, ball joint is good (replaced over the summer with Moog joints), wheel bearings are good, and strut is doing okay too. I'm. Stumped. I don't know what else to check! Yet I still have a grinding noise when brakes are applied at random times. Pads are also wearing down faster than normal. First two sets of pads lasted 100,000 miles. These last two sets have lasted around 20-30K at most. Anyone else experience this issue or have an idea on what to check??
 

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Ok, guys. I'm stumped on this one and thought I'd check here before shelling out more $$ on yet another issue. My last set of pads started squealing, so I replaced with ceramic pads and new rotors. Install went well and took no time at all. Drove as normal, making long gradual stops during run-in. All was well for about 2 months, then they started squealing (not from the wear indicator either). I removed the calipers and pads, applied brake lube to the mounting tabs of the pads and even a light film on the back of each inner pad. Worked for a few weeks and squealing came back.

Now I randomly hear a grinding coming from the LF wheel. Took the wheel off and checked the pads and rotor. Pads are just below 50% and rotor looks great. Caliper guide pins are lubed and moving well. Tie rods are tight, sway bar links are tight, ball joint is good (replaced over the summer with Moog joints), wheel bearings are good, and strut is doing okay too. I'm. Stumped. I don't know what else to check! Yet I still have a grinding noise when brakes are applied at random times. Pads are also wearing down faster than normal. First two sets of pads lasted 100,000 miles. These last two sets have lasted around 20-30K at most. Anyone else experience this issue or have an idea on what to check??
What brand of pads? I would use Toyota- which are Ceramic. Also you could get cheap rotors which could contribute to the problem. I have grinding only after it rains from thin coat of rust that forms. Bottom line use Toyota parts and unless the pads are wearing uneven that should solve the squealing /grinding.
 

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Did you reinstall the stainless clips and pins and are there any shims between piston and pad? I haven't removed mine for a long time and cannot remember but most older cars have anti squeal shims. The fact it improved when you applied brake grease ( was it a copper colour grease that we call copper slip?) suggests it could be that all you need do is remove and re apply to all contact surfaces. Also try filing a chamfer to the edges of the pads all around the pad, this will also help them bed in and stay quiet.
The only other thing I can think of is there is excess wear in the sliders and the caliper is moving/vibrating when you brake.
 

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Discussion Starter · #4 ·
Did you reinstall the stainless clips and pins and are there any shims between piston and pad? I haven't removed mine for a long time and cannot remember but most older cars have anti squeal shims. The fact it improved when you applied brake grease ( was it a copper colour grease that we call copper slip?) suggests it could be that all you need do is remove and re apply to all contact surfaces. Also try filing a chamfer to the edges of the pads all around the pad, this will also help them bed in and stay quiet.
The only other thing I can think of is there is excess wear in the sliders and the caliper is moving/vibrating when you brake.
The replacement pads came pre-installed with shims. The shims are actually coated with a very thin layer of this rubber based material too. To answer your question about the clips, yes they are installed and pads are chamfered as well. I have no idea what type of grease it is that I had to apply. It was purchased at an auto parts store and I just remember it was called "brake assembly lube" or something of that nature. The sliders are moving freely, or at least when I remove the calipers and slide them back and forth with my hand. Now, on the vibration part, I'm glad you mentioned that because if I'm driving at any speed over 70 and gently apply the brakes to slow down to a complete stop, as in exiting onto an exit ramp, I can hear a vibration from that same wheel (left front) almost as if I am driving over those rumble strips along the freeway. I've never driven a vehicle with a bad caliper, but it seems to me this may the culprit...
 

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Never had a bad caliper either but I think you are onto something, you can dismiss the rotor if there's is no shaking through the steering wheel, if it wasn't seating squarely on the hub it would have the same effect, shaking. The fixed part of the caliper is 'fixed' so it can't be that, what puzzles me is how quickly you are getting through pads, could be the slider is sticking and keeping the pad in contact with the rotor, I have never come across worn sliders either but I guess it must happen.
I am looking at my control arm rear bush this afternoon, I'll have a good look at my caliper and get back to you if I can think of anything else.
 

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Discussion Starter · #6 ·
Never had a bad caliper either but I think you are onto something, you can dismiss the rotor if there's is no shaking through the steering wheel, if it wasn't seating squarely on the hub it would have the same effect, shaking. The fixed part of the caliper is 'fixed' so it can't be that, what puzzles me is how quickly you are getting through pads, could be the slider is sticking and keeping the pad in contact with the rotor, I have never come across worn sliders either but I guess it must happen.
I am looking at my control arm rear bush this afternoon, I'll have a good look at my caliper and get back to you if I can think of anything else.
Yes, please do. Thank you. I just ran an errand for work in my car. Only drove about 3 blocks one way. After I got to the other office, I carefully felt the rotors to see if they were very hot. I figured if they are sticking, they would generate a lot of heat. They were blazing hot. Rear drums were very cool. The front right rotor was not as hot as the driver's side. I'm fairly certain stuck calipers are what I'm dealing with. Is there a way to clean/lube them to free them up, to avoid replacements?
 

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Your in luck, rock auto do caliper bushing and guide kits for our rav's
I had a good look at mine and I think it has to be the guides sticking on yours,
Rockauto have a close out sale on right now, no guide pins but crazy prices on tons of other parts including pads, rotors, brake parts, etc etc.
RockAuto Auto Parts

Good luck!
 
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