NO brakes, ABS light, Brake light, Alarm condition- Quick question (1 Viewer)

[boze_man]

2003 LC 100 w/245k miles. We have been having the ABS light/ Brake light/ alarm condition intermittently which causes the undrivable 'no brakes' condition. Being intermittent and not being able to replicate the condition has been very frustrating. Before I replace the MC or brakebooster etc could the wheel sensors be causing this 'zero brakes' condition? I was thinking the wheel sensors would only throw the ABS light and not the full blown undrivable no brakes condition. I didn't want to replace the big ticket items then find out in the end was just a bad wheel sensor...

I have been reading the various threads on ABS booster pump repair & replace and the MC rebuild DIY thread but from what I see the zero brake condition is either the MC or booster/accumulator.

Thanks in advance for any replies...

 

[boze_man]

Update...currently getting replies from these 2 threads...

Master Cylinder Rebuild - DIY

Order correct rebuild kit. Part number for 2000 US model w/ ATRAC is 04493-60330 [edit 6/2018 - this part number is correct for all US 100s. Checked with @beno and while online it will only be listed for 2003-2007, its correct for all US 100s.] Kit is around $50, so a bunch cheaper than...

forum.ih8mud.com

ABS Booster Pump - Repair or Replace? Part Sources? Rebuild in DFW, TX

Appears the abs booster pump -the electric motor- went out today at 294k. I'm about to remove the master cylinder assembly to remove the motor and will DIY the master. Question is are there reliable sources that stock new, rebuilt, or will rebuild my motor? I'm aware I can go to the dealer...

forum.ih8mud.com

Thanks

 

[BullElk]

Steering rack bushings was the culprit for me. All gone with new bushings.

 

[Mike NXP]

Steering rack bushings was the culprit for me. All gone with new bushings.

Your steering rack bushings caused a no brake issue? I could see them causing the ABS or stability control to kick in but it wouldn't cause brake failure.

@boze_man I think you are on the right track. Generally speaking if it was just a sensor your brake pedal should still push fluid and allow for the brakes to be applied. I haven't had this issue so I suppose I'm no help.

 

[boze_man]

Steering rack bushings was the culprit for me. All gone with new bushings.

Hmmm...nothing like throwing a wrench into things...LOL...our rack is on its last legs and due for replacement...

 

[Mike NXP]

Hmmm...nothing like throwing a wrench into things...LOL...our rack is on its last legs and due for replacement...

I could be wrong but I would think if the rack bushings were worn enough to be the problem it may trigger the ABS and the brakes may lock up and do their thing but I don't think it would cause a "no brake" situation like you described. I've seen a few forums where loose wheel bearings or rack bushings cause the ABS to trigger but not a loss of braking power.

Does the pedal go to the floor when it happens?

 

[boze_man]

Agree...

It is the condition noted in those threads where you have to use all your leg strength to even achieve any sort of braking...totally unsafe. It is not the condition where there is no pedal resistance and it just flaps to the floor like when you have no brake fluid...

Given the age of the 100 and the steeply reduced cost of the whole MC unit I am thinking best to go that route...

 

[Dwight S]

It’s your brake ABS pump/master cylinder. Take it from someone who’s replaced the pump motor with a rebuilt pump. Then two years later replaced the entire unit with a “low mile” one. And then two years later had to replace it again, just bite the bullet and buy a new one from your Toyota dealer.

 

[boze_man]

It’s your brake ABS pump/master cylinder. Take it from someone who’s replaced the pump motor with a rebuilt pump. Then two years later replaced the entire unit with a “low mile” one. And then two years later had to replace it again, just bite the bullet and buy a new one from your Toyota dealer.

100% agree

 

[Chases Elk]

I'm working through a similar problem. The booster motor issue seems to be corrosion related. I saw somebody say they tapped the electrical connections to get the booster motor to work. I tried that, and it did work for me to at least temporarily get the booster to pressurize the system and the alarm and lights to turn off.
I have a remanned booster motor accumulator assembly to swap on the MC today, and I'll be looking at that corrosion issue.

 

[boze_man]

Ordered the MC unit from McGeorge and had it installed. All working as it should...thanks to everyone for the info and support.