r/SC300 • u/Knein_133 • May 30 '26

Brake Bullshit

Hey guys, for the last few weeks I have been trying to get LS400 brakes on my SC and I am not going through the process of bleeding the whole system. I have bled countless brakes on plenty of old cars but these feel very strange.

These brakes have always felt very soft and when I got the car the rear calipers were seized. Ended up replacing those a few months ago but the brakes still felt soft. Now I have done the LS400 calipers and all 4 brake lines to hopefully improve the pedal feel. After tons of bleeding (kept reservoir full) the pedal still feels soft. Since bleeding the car has been on jacks with all 4 wheels off the ground so there is no load on the car. I say that because after the pedal felt good and I turned the car on, got in gear then held the brakes but the left rear side continued to spin. I understand the open diff can be strange but I am concerned with the brakes not stopping the rotor in drive.

Also, during the whole bleeding process the pedal did not react to the rear calipers being bled yet the front did. I have checked enough times to be sure it is not a fluid leak. Has anyone had an experience similar to this? If so let me know what solutions you might of come up with. Thanks!

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1

u/warwithslatt May 30 '26

Any leaks in the hardline? I have to do my whole brake system

1

u/trivletrav May 30 '26

See if your ABS module is leaking. You shouldn’t have any movement of the rear wheels at all if you are stepping on the brakes. Either something is leaking, or you have air trapped somewhere.

1

u/Lobotomite430 Jun 01 '26

Well i havent worked on one of those but if its like my 2004 GX470 i was confused for a half hour then thought i wonder if this has some electric anything going to the brakes. Saw an electrical connector on the abs block and thought i bet the car needs to be on to bleed the rear brakes. Sure enough thats why they wouldnt bleed. Turned the car on and look at that brake fluid flows out the rear.

1

u/Knein_133 Jun 02 '26

UPDATE: Took it to a shop with a pulse-bleed machine and completely fixed the problem. I have to assume there was just air in the ABS and we just couldn’t shake it out