ls400beave

So my brakes on the 98 LS400 on the passenger side were going thump thump thump when you would stop at high rate of speed. last year I replaced the pads and rotors because of this and it seemed to make the issue go away. Now it is back so I ordered a new caliper and it was worse. Then I replaced all the pads and rotors again and the problem is now awful.. Need help on figuring out what this could be. Brakes have been bleed and brake fluid comes through the line. Do you think it has something to do with ABS box air lines? Let me know your thoughts..

RA40

iTrader: (6)

Is this front or rear?
Miles on car?

Ever have the strut bar or bushings replaced? Pretty much any thump-clunk coming from the front going over bumps or hard braking can be attributable to worn strut bar bushings.

ls400beave

This is on the front passenger side. Car has 234,000 miles. I just had the strut rod bushings replaced last weekend. So I decided to redo the brakes. It is like the caliper is not squeezing tight enought on the pads and they are as loose as can be. So when you hit the brake it is like thump, thump, thump. The caliper is brand new as well. I order a new brake HOSE today that connects to the caliper (not the brake line from the master cyliner). I am not sure what else would cause that just on the passenger side? I am stumped!?!

PureDrifter

iTrader: (10)

pad shims & springs? it has the full fitting kit right?

ls400beave

Yes, I even purchased the caliper kit.. Getting ready to put new hose on today. I read some great feed back online and I hope it that is it.. Below is a couple of comments from people who delt with similar issues on LS400.

My friend had the exact same problem. The brake kept hanging up. We replaced the rotors, calipers, etc. still happened. The right answer was the rubber brake line as mentioned above. What happens is when you apply the brakes the fluid pressure is enough to actuate the caliper, but the hose is expanded on the inside, kind of like coronary artery plaque, and when you release the pressure the fluid doesnt back up the hose. Kind of like a one way valve. Replace those lines and you should be fixed....Hard problem to diagnose, but a cheap fix....

mspearl95

so is your brake dragging? or only thumping when you step on the brake pedal?

ls400beave

I am not sure what you mean by dragging.. However, I did replace the brake hose to the passenger caliper today and the car is better. However, it is still thump, thump, thump when stopping at high rate of speeds. it does feel more even on the front but still more feel on the passenger side. I am also going to replace the vacuum hoses inside the motor that shoot air in and out of master cylinder. I am kinda of out ideas. After that I might concentrate on the brake booster (located on passenger side) and see if I can see any bad lines..

Yamae

I once had a similar problem with another car. It was caused by a worn hub bearing. Too much play caused the problem.

j2b4o

+1
Was scrolling down to post the exact same thing.