Sherl

While i have found some across the web
https://www.organizedgaragestatus.co...lipers-Rebuild

Is there a way to rebuild without removing from the brake line. I just bleeded my lines like 4k miles back so if I remove and rebuild the caliper and put them back it would bring back air inside the system right? So any DIY is highly appreciated on this. I am trying to rebuild just front driver side as I have a sensation that the driver side caliper is seizing.

DrC10

The brake system needs to maintain a left/right balance that repairing just one side may disturb. There is no practical way to overhaul the caliper on the car...most auto parts chain stores have good quality rebuilt calipers for a reasonable price. Let's start from the beginning though...
If you think one side is dragging, use a non-contact thermometer to check the left and right brake temperatures after a short drive. One side reading significantly higher would indicate that you are correct.
BUT, don't start at the caliper! I remember more than once having a brake hose swelled shut on the inside, and causing the same symptom.
Just my 2 cents...Good luck!

Sherl

My front end/steering just shakes when I brake. Mostly I can absorb from the driver side. So my mechanic did suggest me that the left calipers are dragging/seized. Since my rotors are only 40k old but car itself is 230k old, I guess it has to do with the caliper instead of rotors.
What else do you think can create shake while braking in the steering wheel? .

DrC10

The vibration can be caused by warped rotors or deflection of the radius arm bushings. Might want to have those looked at too.

Sherl

It only happens when I apply the brakes and sometimes the feeling of dragging vary. Sometimes I feel its not as harsh as the others. If it all the calipers. Does the sliding pin or the pistons?

bradland

If it only happens when you apply the brakes it's prob a 90% chance your rotors are warped. This is not uncommon and it's an easy fix. Find a shop that can resurface without removing them, most modern shops can do it, and you should be good.

DrC10

The caliper will have to be moved out of the way to resurface the rotors. It's the perfect time to see how easily the piston moves back into its bore, and make sure the slide pins are lubricated and moving freely. Later 4 piston calipers do not have slide pins.

oldskewel

iTrader: (1)

And to answer the initial question directly ... when rebuilding the caliper, you will remove the piston(s), at which point, air will be in the caliper. So removing from the brake line is not an issue. You will need to bleed the brakes anyway. When doing that, you probably will want to do something to make sure the brake fluid does not ALL leak out, causing air pockets up in the master cylinder, etc.

But if you want to just replace the rubber boots and slide pins, cleaning and greasing, that could be done without removing the piston(s) or disconnecting the brake line. But that's not a full caliper rebuild.

If you can't find a DIY, it may be becuse there is really not much to it. Here's my writeup, off the top of my head, all part numbers are for my '91:

1. buy the overhaul kit from lexus. For my '91 front is 04479-50030 , rear is 04479-50020. One kit for each caliper.
2. remove caliper from the car, plugging the brake hose so fluid does not all leak out.
3. clean it, take it apart. compressed air may be useful to get the piston(s) out, but make sure they don't go flying (which they will if you don't prevent it)
4. inspect for rust, roughness, replacing or honing as needed (a common failure [happened to my car] is when the piston boot fails (cut, not seated, etc.) allowing water in and grease out, leading to some rust and sticking; in my case I bought a new piston and honed the caliper bore)
5. pin bushings may need replacing (47769-50010 front lower, rear lower ; 47769-50020 front upper ; rear upper uses no bushing)
6. pins may need replacing
7. put it back together with caliper grease (08887-80609) and new parts from the kit
8. re-install caliper
9. bleed brakes

So basically, that is: take it apart, inspect, clean, put it back together with new parts, just like rebuilding anything, except these systems are so simple that there's not much more to add.

But a less direct answer would be to consider warped calipers or worn suspension components as well, both of which could cause vibration while braking.