dicer

12 and 17 is the hex size not the bolt size.

ajahearn

Sorry about not pointing out the setup difference. For the benefit of those coming after me, a couple of points to note over the link mentioned earlier in this posting.
- I first disconnected the clip that engages the pins (on RH side it also holds the wear sensor wire)
- I then removed the lower pin, then the anti-rattle spring (+ sign), followed by the upper pin
- For the RH side only, I then removed the very tiny clip around the wear sensor and using a screwdriver gently slid it up and out of the way (rocking slightly back and forth) - moving the sensor wire out of harms way
- Aaccess to the caliper bolts is much easier if you rotate the wheel such that the back end of the rotor is outward. Trying to access them any other way is very tight and beyond my strength
- I used a 800lb 1/2 pneumatic impact wrench @90PSI with 6.4SCFM + some liquid wrench to remove the bolts (best to give the liquid wrench/wd40 time to work and things will be much easier). And lest you think I always do things the correct way I destroyed a 17mm socket that wasn't designed for pneumatic operation - luckily no explosive results and I had the correct socket, just hidden
3) With the caliper free the pads almost fall out. Pay careful attention to the layers of shims and spacers or refer to the diagram provided in the previous posting.
4) A 6"C clamp with either a small metal plate or hard wood works for compressing the pistons, no need for any special tools and no need to turn as they are compressed - do not forget to open the cap on the brake fluid reservoir and be sure to watch the level as you compress - brake fluid is a very strong solvent
4) I opted to install the calipers again before inserting pads, etc. - don't forget to torque to proper force (87ft/lbs)
5) re-insert the pads in the proper orientation, especially so that the wear sensor can be inserted properly
6) for the RH side again, insert the wear sensor and don't forget the ridiculously small clip that goes around it
7) When putting back the pins I test fitted them as one was tight with the new pads so pick the harder one first and I make sure to orient the hold at the end such that the clip can go back on properly.
8) After everything is installed and tightened, I bled the brakes with the help of my wife. Always a good thing to do but I see from my fluid its time to replace all the fluid (dark green - a job for another day)
9) Only bad news for me is the back ones need to be changed as well - next weekend.

Hope this helps. I took some photos if anyone wants more details. I greatly appreciate the help of all the posters for their insight. This car is such a nice car - it shifts so smoothly it is hard to even detect it.

ajahearn

I also forgot to add that you should bed your pads carefully. There are many recommendations on bedding. I just go a few short runs with different stopping strength and include reverse in the equation. No heavy braking for as long as you can muster.

dicer

And how did you bleed the ABS unit? Does it have trac?

ajahearn

Do the ABS systems on the LS400 have their reservoir? I don't see that in the 92 service manual a friend loaned me. Assuming not, I just used the bleed screw directly on the caliper. I just attached a small hose to collect the fluid, opened with a 10mm wrench, started the car, pressed the brake pedal a few times until I could see no air in the line, closed it off.

I am going to flush the entire system as the fluid is already dark. I wasn't going to bother with a vacuum pump to pull the fluid through the system. My friend's 92 manuals shows the master cylinder with a bleeder so I will look for that when the time comes. The manual doesn't give a priority to the left or right side but as expected it says to start with the rear so I will likely do RR, RL, FR, and FL. I use a syringe to get us much fluid out of the master before starting if I don't have the bleed screw.

Let me know if I am missing something, and again this is a 96 model car.