Symptoms of faulty brake master cylinder & booster?
02-07-10, 02:38 PM
#1
Symptoms of faulty brake master cylinder & booster?
Ok, i bought the brake master cylinder rebuild kit from sewell, swapped it in, but now seems that it didnt solve the problem or even made it worse. i think my brake booster is busted.
Here's the symptoms, with engine off, the brake pedal builds stiffness after 5 pumps, turn on engine, and the brake pedal sinks to the floor. with engine on, i pump the brake pedal several times only to have it sink to the floor. after 1 long press, or 2, i hear the buzzing sound of the booster turning on.
i have bleed the brakes 4 times, traditional method, new method, and twice over. went thru 2L of brake fluid.
took the car out for a spin, got about 20ft and noticed my brakes barely work, and the pedal sinks to the floor. checked the calipers they are moving no issue.
The question i have is,
Do they sell the brake booster seperately? how does it look like? and if not, where can i purchase a brake master cylinder. I know its sunday thus all dealers are closed. i figure i would ask clublexus first.
How much am i looking for?
Other than sewell, since when i use their online system, it just directs me to a rebuild kit (which i bought and didnt work), is there anywhere else i can buy oem parts online?
Thanx for all your help. just one big headache right now.
Here's the symptoms, with engine off, the brake pedal builds stiffness after 5 pumps, turn on engine, and the brake pedal sinks to the floor. with engine on, i pump the brake pedal several times only to have it sink to the floor. after 1 long press, or 2, i hear the buzzing sound of the booster turning on.
i have bleed the brakes 4 times, traditional method, new method, and twice over. went thru 2L of brake fluid.
took the car out for a spin, got about 20ft and noticed my brakes barely work, and the pedal sinks to the floor. checked the calipers they are moving no issue.
The question i have is,
Do they sell the brake booster seperately? how does it look like? and if not, where can i purchase a brake master cylinder. I know its sunday thus all dealers are closed. i figure i would ask clublexus first.
How much am i looking for?
Other than sewell, since when i use their online system, it just directs me to a rebuild kit (which i bought and didnt work), is there anywhere else i can buy oem parts online?
Thanx for all your help. just one big headache right now.
02-07-10, 02:58 PM
#2
The master cylinder is an all in one unit, meaning it has the Abs computer, booster, pump, etc. These things are expensive as hell.
I need to change mine out cuz it makes the horrible scretching noise every single time I press the brakes. It still works good but it is annoying to have make that loud noise.
Is it easy to swap out the unit? Don't know if I should attemp swap it myself.
I need to change mine out cuz it makes the horrible scretching noise every single time I press the brakes. It still works good but it is annoying to have make that loud noise.
Is it easy to swap out the unit? Don't know if I should attemp swap it myself.
02-07-10, 03:33 PM
#3
well, ill put it this way, i took the whole unit apart before realizing all u needed to do was remove the dust shield that protects the brake piston on the brake master cylinder.
the unit which i assume looks like a big pop can, must be the booster. it has 1 hard line attached to it, 1 rubber hose, and what looks like a positive and negative terminal.
is it easy to remove? relatively, its held in place with 3 or 4 hex bolts (u need an allen key to remove them)
the hardest part was removing the brake master cylinder/booster. under the dash there are 4 12mm nuts.
you need to disconenct the brake light sensor, the pin and cogger pin that holds the brake master cylinder piston to the brake pedal, and a spring that holds and pulls the brake pedal upward. after u remove these, u need to unscrew the 4 hard lines that run to the brake master cylinder/booster unit. you will also need to unplug 5-6 plugs, if i remember right there are 4 to one side, and 2 facing forward. they all are different sizes and so u cant really screw up putting them back in place.
the unit which i assume looks like a big pop can, must be the booster. it has 1 hard line attached to it, 1 rubber hose, and what looks like a positive and negative terminal.
is it easy to remove? relatively, its held in place with 3 or 4 hex bolts (u need an allen key to remove them)
the hardest part was removing the brake master cylinder/booster. under the dash there are 4 12mm nuts.
you need to disconenct the brake light sensor, the pin and cogger pin that holds the brake master cylinder piston to the brake pedal, and a spring that holds and pulls the brake pedal upward. after u remove these, u need to unscrew the 4 hard lines that run to the brake master cylinder/booster unit. you will also need to unplug 5-6 plugs, if i remember right there are 4 to one side, and 2 facing forward. they all are different sizes and so u cant really screw up putting them back in place.
02-07-10, 03:45 PM
#4
A brand unit is crazy expensive. It'll run in the neighborhood of $1500 or so.
You're better off finding a used one that still functions. I know a few CL member here had done the same and it cost them about $400 for the unit. I wish Toyota would have separated the components instead.
You're better off finding a used one that still functions. I know a few CL member here had done the same and it cost them about $400 for the unit. I wish Toyota would have separated the components instead.
02-07-10, 03:58 PM
#5
its just confusing.
i did a search for "online lexus parts"
and found these 2 links
"brake booster"
http://www.trademotion.com/partlocat...99&catalogid=1
"master cylinder"
http://www.trademotion.com/partlocat...99&catalogid=1
way different on prices...
i did a search for "online lexus parts"
and found these 2 links
"brake booster"
http://www.trademotion.com/partlocat...99&catalogid=1
"master cylinder"
http://www.trademotion.com/partlocat...99&catalogid=1
way different on prices...
02-07-10, 04:20 PM
#7
yeah, and thanx for the pm. im looking at my options right now.
but basically a wasteful weekend. was all happy about getting the ls400 calipers on! then the passenger busts a leak, now my master brake clyinder is crapped out.
and i think my battery is dying, haha, so im charging it right now.
but basically a wasteful weekend. was all happy about getting the ls400 calipers on! then the passenger busts a leak, now my master brake clyinder is crapped out.
and i think my battery is dying, haha, so im charging it right now.
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02-07-10, 05:35 PM
#8
same thing happened to me when i did my ls upgrade but it ended up that a rear line burst replaced rear lines bleed the lines again now everything is fine... cleans14 when he did his motor swap he also swaped out the booster to a manuel supra booster and master cylinder i have been thinking of this route just because i am worried about the 1500 dollar replacement when this one goes out.
