Secretpraise27

I have a 2wd lexus rx300 that I bought used thinking it only had brake pads to change. Found out I had to work with the brake caliper pistons and check the abs sensors and get some suspension parts, get new boots installed on the rack and pinion and other things.

The main thing was that the front brakes were stuck and the abs, vsc and trac lights were on. Once I released the master brake cylinder from the booster to adjust the nut, this released the brakes and I thought I had fixed the issue. When I started driving, i noticed the abs light had shut off and it was braking fine. But it didn't last longer than a block. The abs light came back on and the braking problem continued. I disconnected the front sensors and even tried disconnecting the entire abs system and also bought new front calipers, but it still had my brakes locking up.

maxSteel

Welcome to ClubLexus

If the ABS light is on the ABS system is disengaged. You can read the ABS codes following this procedure https://www.clublexus.com/forums/rx-...ml#post9104458

If the front brakes released when you were working on the master cylinder maybe the problem is there.

Secretpraise27

The thing is that after working again with the master cylinder and putting it back, the abs light stays on and the brakes are still stuck. Do you think I should buy a new master brake cylinder?

maxSteel

You can have more than one problem. My ABS light has been on for about ten years. If you want to know why your light is on follow the procedure to read the codes.

I can't say of your master cylinder has an issue but if disconnecting the brake lines from it relieves the stuck condition it would seem likely.
I doubt the individual lines to the front wheels both failed at once.

salimshah

I speculate the problem is in return flow of the brake fluid. When it is pushed down there is enough pressure by the piston n master cylinder but the return is by run out in the rotor.

I would open up and close each fitting progressively down the line from the master cylinder and see if the master cylinder drains under gravity. You can aid gravity by low pressure on top of the master cylinder. Most notorious are the rubber lines which swell up internally.

Salim

sktn77a

iTrader: (2)

I had a similar issue. No lights on but the caliper was stuck and it turned out to be the hoses. Didn't believe it at first but replacing the caliper didn't fix it - new hoses did.

maxSteel

I've had it happen too, but what are the odds of both front brake lines failing at once?

salimshah

Very reasonable argument and that is why I suggested starting at the source and work down towards the end. If it was inly one wheel, then the trouble shooting should start from the wheel back.

I would definitely test out the flow issues before tracing the ABS warning. ABS tracing should start with good battery and AC ripple on the alternator output.

Salim