Disc brake with 4 pistons

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Originally Posted by Gebo
I'd probably go new if I had the money and I planned on keeping the truck. One thing I didn't learn until later in life was the importance of lubing the caliper pins. If I had plenty of money, I'd at least "consider" the rotors as well. Just do them all at once. IF I had PLENTY of money. Toyota makes 3 different lubes for brakes. 1. Anywhere metal touches rubber 08887-01206 (Rubber Grease) 2. Ears of pads 08887-80609 (Brake Caliper Grease) 3. Back of pads between shims and back. Comes with pads or Molykote AS-880-N Very expensive if you go OEM lubes.
These are probably fixed calipers...no pins to lube.
 

JHZR2

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Originally Posted by supton
Why do people say they are shot? Is the rust impeding heat transfer? The pistons still move freely, once free the pads do not rattle about. I haven't tested the bleeder in a while. so that might condemn them I guess. If it wasn't for the torn boots I wouldn't think twice about running them longer (and TBH all the pistons that have seized on me had perfectly good rubber boots so... what good are they for?). These are a really long ways from somehow breaking in half or otherwise falling off. shrug
Because they look horrible in the worst places. The piston is rusty. I could get by with a rusty body (you can scrape it, paint it, acid it, etc.), but the pistons look rusty. Couple rusty pistons with breached and ruined seals, and it's likely that the piston inside the bore is rusty too. At least up to the square cut seal. Push a rusty piston in against a new square cut seal and you're asking for trouble, IMO. Buying new pistons for those calipers is more money then it's worth, IMO. I'm an advocate of diy rebuilding. It's not a hard job. But I think these will be good time after bad...
 
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I would replace those. Look into using Fluid Film on the undercarriage to reduce corrosion. Good luck.
 

supton

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Originally Posted by JHZR2
Originally Posted by supton
Why do people say they are shot? Is the rust impeding heat transfer? The pistons still move freely, once free the pads do not rattle about. I haven't tested the bleeder in a while. so that might condemn them I guess. If it wasn't for the torn boots I wouldn't think twice about running them longer (and TBH all the pistons that have seized on me had perfectly good rubber boots so... what good are they for?). These are a really long ways from somehow breaking in half or otherwise falling off. shrug
Because they look horrible in the worst places. The piston is rusty. I could get by with a rusty body (you can scrape it, paint it, acid it, etc.), but the pistons look rusty. Couple rusty pistons with breached and ruined seals, and it's likely that the piston inside the bore is rusty too. At least up to the square cut seal. Push a rusty piston in against a new square cut seal and you're asking for trouble, IMO. Buying new pistons for those calipers is more money then it's worth, IMO. I'm an advocate of diy rebuilding. It's not a hard job. But I think these will be good time after bad...
Took me a moment to see what you're seeing--the outside of the piston is rusty. I didn't see rust on any of the piston that should be behind the seal. $100 and change per side. Guess I'll be doing those some point this summer.
Originally Posted by Amkeer
I would replace those. Look into using Fluid Film on the undercarriage to reduce corrosion. Good luck.
What makes you think I don't? I did skip doing it this past fall, but otherwise it's had several years of FF. For naught. Well, I do think it slowed down the rust, the frame is in very good shape (something you never hear about for a Toyota) but all the various bits that hang down in the wind are quickly flaking over. FF just doesn't stay on at all in high wash areas. Only way I found to make FF work was to apply twice a year and do touchups during tire rotations.
 

supton

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Originally Posted by thooks
These calipers are 3 years old?
10 years old, unless if someone replaced them in the 0-3 year range (I bought it when it was 3 years old).
 
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Ok, sorry. I mis-read when you said rotors.... I have a 2014 Tundra. If I were you, I'd figure out how to buy the least expensive OEM parts and do it. Whether it's shipped or getting a local dealer to closely match online pricing. I put PowerStop Z36 rotors and pads on my Tundra about 60k miles ago. I'm going back to OEM next time. I have 2 sets of rotors sitting around, I might get a pair turned and see if I can stretch the pads out until they die. My rotors now have vibration when braking at high speeds. These are cross-drilled, slotted rotors and I followed the PowerStop break-in procedure to the letter. I also spent an hour with a wire brush, both on a grinder and hand brush, meticulously cleaning the rotor mating surface. I'm very disappointed in the PowerStop products. I saw NO increased stopping performance, either.
 

supton

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Right now it's all OEM up front (rear has a Raybestos caliper after one seized). Looks like Raybestos has some $102 calipers with no core charge at Rock, so I might do that, and grab a set of EHT pads while I'm at it, as those pads seem to work well on my car, might as well put some on the shelf.
 
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I am surprised you got the cross pins out. I have owned both a Tundra and FJ Cruiser and the brake calipers seem to rust out fast than other vehicle makes in my opinion. I vote for replacement calipers also.
 

supton

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Originally Posted by Hootbro
I am surprised you got the cross pins out. I have owned both a Tundra and FJ Cruiser and the brake calipers seem to rust out fast than other vehicle makes in my opinion.
I have my moments of stubbornness (and stupidity). I'm also getting well-practiced on removing these particular pins, it's either the 3rd or 4th time I've done it, and there's 4 to do each time.
 
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A lot of early disc brake systems used 4-piston calipers. Is this design making a comeback? I had them on a 1965 Rambler. As I recall they had to be shimmed to assure proper centering.
 
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This design has been used on the front of Toyota pickups for a long time. It's relatively trouble free. No slide pins or pad ears!
 
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