mehall

This may be clearer than my past posts:

1. Is it possible to disable the ABS and still have brakes? If so, how?

2. What would cause all 4 wheels to lock up in about 2 miles?

-- all hydraulic rubber lines are new

-- new MC (2x - thought new one was bad)

-- power booster, pedal & brake switch checked by a local certified mechanic



Back ground:

I bought the car with a demonstrably failing MC; installed rebuilt MC and drove home just fine, about 80 miles. A few days later, the rear brakes started locking up after several stops; cracking open the rear line released the brakes. We replaced the rubber brake lines (4). A few days later, it started again. Mechanic tested the system and replaced the "new" MC and the car did fine for a few weeks.

Then it started locking all 4 corners. It does't always free up overnite, but a wrench on both brake lines will always work. The wierd thing is that if I do not use the brake at all, except to put it in drive, about 2 miles or less of driving will lock them up.

Our mechanic says he's over his head; he has run the troubleshooting prosses from ALL Data and cunsulted other sources and could only tell me the problem in in the ABS system - for whcih had no resources. We are about 50mi from the nearest Lexus dealer if I were willing to pay their rates...

A possible piece of the puzzle: when we were replacing the brake line, we encountered a hose that was simply lying on the caleper in a ring - not attached to anything. I'm thinking it is the speed sensor, but it lookeds incompleat.

PureDrifter

iTrader: (10)

that "hose" is probably one of the brake wear sensors...

you need to post the year of your LS in the OP

could be a few things, sounds like a possible vacuum related issue, or could be ABS block/pump, MC, crap in the lines, etc...

mehall

1994, no TRAC, no air suspention.

You presented a endless list of possibilies. How about a link to trouble shooting info?

I would be stunned if someone here came up knowing an exact soulution.

RA40

iTrader: (6)

Check the ABS sensors for any breaks, poor connection, etc. Unplug, plug back in.

Read through this the ABS codes:
http://www.lexls.com/tutorials/intro/codereading.html

mehall

I suppose I should also mention that I bought the car with a dark dash, which I can repair so it sits near the bottom of the listl - - -

- - - - unless the broken cluster could be causing ABS issues. [?]

I will use the codes I might find. Thank you.

I didn't know it was OBD1 - I thought it was '2' and couldn't find a reader.

mehall

Had a new thought...

...do I need to fix the instrument cluster first?

PureDrifter

iTrader: (10)

you'd need to fix it enough to read the codes, yeah...

mehall

Turned out the new master cylander was being compromized by some sticky goop hiding in the resevoure that caused the lines in the cylamder to clog up.

Replacement NC parts do not include a new fluid resevoure. You should thourothly clean it before installation.