My mechanic just replace the rotors and front brakes on the GX, he stated that the FL caliper is seized and need to be replace. Is this pretty common ?
also do you guys think I need to replace the FR as well now or wait till problem occur ?
Thank you

 

Yes, this is a fairly common problem.
If I was to keep the car for a while, I'd replace both calipers at the same time and be done with it. If cost is an issue, it's OK to replace just one for now.

 

Not unusual at all, I think I've replaced 3 front calipers on our at this point.

 

is there anyway to avoid this, cleaning caliper, lubing pins, better aftermarket? why is this caliper so vulnerable compared to others?

 

This is the exact question I've been asking. I've never had a single caliper replaced on any vehicle ever - and i've owned plenty of different makes/models. However i'm starting to have some front caliper issues now. But then again I'm approaching 170K miles probably on the original ones so maybe asking too much.

 

thank you for the input, is there any preventive maintenance so it won't seized in the future ? because I'm keeping the car for another 4 years or so.
Thank you again.

 

Just replace both fronts (to even out braking, and because they're the same age) and drive it.

So far as preventing it from happening again .. I can't tell you to avoid panic stops (which would rapidly heat them up), because panic stops happen and if you need to stop, you need to stop. But if you live in the salt zone, run the truck through a car wash that has an underbody spray every so often. Do your brake fluid changes every 2-3 years and check the pin grease and piston boots at that time.

Chip H.

 

I had that happen to me as well. I replaced just the one that was seized, but I took off the other side that was still functioning and greased the crap out of it with Dielectric grease on all contact points, boots, sleeves, you name it. Everytime I rotate the tires, I check the pin slides and lubricate them up. Its an extra step, but I feel its worth it.

 

Dielectric grease has a low melting point. Its definitely worth it to use specified brake caliper lube.
Either Permatex's Ultra disc brake caliper lube or Ceramic extreme brake parts lubricant work really well up to 3000*F and do not break down the rubber boots.

 

Is it the sliding pin or the piston with the fluid behind it that seizes?

 

The lower piston (inside I think) was frozen on each side of mine at 87k miles when I bought it. The brakes pulsed a bit and grabbed unpredictably when coming to a complete stop. You could clearly see a rusty ring around the piston and on the back side of the pad. All highway driven miles around Dallas, in relatively mild weather with a spotless undercarriage.

 

just something to consider inspecting to determine if pistons are frozen, check the brake pad abutment clips. The clips which the ears of the brake pads slide back and forth on. Often they are not changed out in between pad changes. They can accumulate caked on brake dust and prevent the brake pads from being pushed towards the rotor or retract back. These clips should be cleaned and sparingly lubed.

 

The lower pistons usually seize, but also the pads can freeze on the sliding pins. Use disk brake lubricant on the sliding pins to keep them free and to allow the pads to move freely.

 

Stuck caliper piston(s) problem just occurred on my 2004 GX at 148,000 miles. I picked up new rotors, pads, flex brake lines and rebuilt calipers. I painted the rebuilt calipers flat black. Will be installing the new stuff soon. I'm not going to turn in the Lexus calipers for the core deposit refund. Instead, I'll clean and rebuild the original calipers using genuine Lexus caliper rebuild kits, bag the calipers and keep them for 'next time'. The GX was due for a full brake fluid flush anyway. I received a repair estimate for $800 to $1100 from a reputable indy shop . I was able to buy everything to do the complete front brake rebuild for about $500.