Hey all-
'06 spongy pedal, slowly goes to the floor - no leaks on brake lines, or at calipers, and not losing fluid in reservoir. No screeching pump, ABS or VSC lights. I'm guessing master cylinder seal(s) leaking. I could only find a MC rebuild kit for the 03-04 years, so I bit the bullet and ordered a Master Cylinder, Booster, Pump assembly (47050-60111) from my local Lexus dealer (after they price-matched the cheapest part I could find online). Part should be here in a couple days. Stupid expensive, but I need to get this fixed ASAP as I'm borrowing a friend's car for a few days. By the way, the master cylinder part by itself is only $50 cheaper than the whole assembly with new accumulator, pump, master cylinder, etc. - really, Toyota? Junk yard wanted $750 for used assembly with 210K miles on it, so maybe not such a great deal after all. My feeling is just go new and not have to worry about it for many more years (hopefully).
Can anyone provide details on how exactly to bench bleed the MC before bleeding the lines? I'm not sure if this is even really necessary, as the brake bleeding instructions in the FSM includes bleeding the Booster/Accumulator Pump Assembly (step 2) and the Master Cylinder Solenoid (step 4). For the MC solenoid bleed, I'm assuming this is the same as using the Techstream method to activate the ABS pump used to bleed the rear brakes (no "Intellingent Tester" required as per the intructions below)?
So, is it required to perform some other process to bench bleed the Master Cylinder also? I'd appreciate some help on how to do this if it should be done. Do you need some sort of MC bleeder kit to do so? First time doing this work, so appreciate the help. Asssembly removal and reinstallation process is pretty simple, so not worried about that part. Is the process pretty much the same as the manual bleeding of the brake line at the caliper (pump and hold brake pedal), but just cracking each brake line connection at the master cylinder until no air comes out?
Also, someone on another forum mentioned that it will it be necessary to have the Yaw Rate and Acceleration Sensor Calibrated. Is this true? If so, can it be done with Techstream, or will I have to bring this in to the stealership? I have had some weird issues recently where VSC will kick in shortly when I make a right turn going uphill, I wonder if this would resolve that issue too?
Thanks for the help!
BLEEDING
NOTICE:
• Wash off brake fluid immediately if it comes into contact with a painted surface.
• If the brake pedal is depressed with the reservoir cap removed, then brake fluid will spatter.
HINT:
• If any work is done on the brake system or if air in the brake lines is suspected, bleed the air from the
system.
• When bleeding, keep the amount of the fluid between the Min. and Max. lines on the reservoir.
1. FILL RESERVOIR WITH BRAKE FLUID
Fluid:
SAE J1703 or FMVSS NO. 116 DOT3
2. BLEED BRAKE BOOSTER W/ACCUMULATOR PUMP ASSEMBLY
HINT:
Perform this step only if the brake booster with accumulator pump assembly is removed and/or installed.
(a) Turn the ignition switch off, depress the brake pedal 20 times or more to release the pressure from the
accumulator (Procedure "A").
(b) Fully depress the brake pedal 10 times (Procedure "B").
(c) Turn the ignition switch to the ON position and start the brake booster pump (Procedure "C").
(d) Make sure the pump operates for 8 to 14 seconds.
If the pump does not operate as specified, repeat procedure "A" to "C" and recheck the operating time.
3. BLEED BRAKE LINE
(a) Front brake line
(1) Turn the ignition switch to the ON position and wait until the
pump motor has stopped.
(2) Connect the vinyl tube to the brake caliper.
(3) Depress the brake pedal several times, then loosen the
bleeder plug with the pedal held down (Procedure "D").
(4) At the point when the fluid stops coming out, tighten the
bleeder plug, then release the brake pedal (Procedure "E").
Torque:
11 N·m {112 kgf·cm, 8ft·lbf}
(5) Repeat procedure "D" to "E" until all the air in the fluid has
been bled out.
(6) Repeat the above procedures to bleed the other brake line.
BRAKE: BRAKE FLUID: BLEEDING; 2006 MY GX470 [08/2005 - ] https://techinfo.toyota.com/t3Portal/document/rm/RM00V0U/xhtml/RM...
1 of 3 2/7/2022, 5:27 PM
(b) Rear brake line
(1) Turn the ignition switch to the ON position and depress the
brake pedal.
(2) Connect the vinyl tube to the brake caliper.
(3) Loosen the bleeder plug and release air.
HINT:
Brake fluid is sent through the pump, so keep the brake pedal
depressed until the air is completely bled out.
(4) When the air is completely bled out of the brake fluid
through the bleeder plug, tighten the bleeder plug.
Torque:
11 N·m {112 kgf·cm, 8ft·lbf}
(5) Repeat the above procedures to bleed the other brake line.
4. BLEED MASTER CYLINDER SOLENOID
HINT:
Perform this step only if the master cylinder solenoid is removed and/or installed.
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Select "ACTIVE TEST" mode on the intelligent tester.
(d) Connect the vinyl tube to the rear brake caliper.
(e) Loosen the bleeder plug.
(f) Select "SRMF & SRMR" to drive the solenoids and bleed air from the rear brake caliper (Procedure "F").
NOTICE:
Do not depress the brake pedal.
HINT:
• Brake fluid is sent through the pump.
• To protect the solenoids, the intelligent tester turns OFF automatically 2 seconds after every solenoid has
been turned ON.
(g) Repeat procedure "F" until all the air in the brake fluid is bled out.
(h) When the air is completely bled out of the brake fluid through the bleeder plug, tighten the bleeder plug.
Torque:
11 N·m {112 kgf·cm, 8ft·lbf}
(i) Repeat the above procedures to bleed the other brake line.
(j) Turn the ignition switch off.
(k) Turn the ignition switch to the ON position.
(l) Clear DTC .
5. CHECK FLUID LEVEL IN RESERVOIR
'06 spongy pedal, slowly goes to the floor - no leaks on brake lines, or at calipers, and not losing fluid in reservoir. No screeching pump, ABS or VSC lights. I'm guessing master cylinder seal(s) leaking. I could only find a MC rebuild kit for the 03-04 years, so I bit the bullet and ordered a Master Cylinder, Booster, Pump assembly (47050-60111) from my local Lexus dealer (after they price-matched the cheapest part I could find online). Part should be here in a couple days. Stupid expensive, but I need to get this fixed ASAP as I'm borrowing a friend's car for a few days. By the way, the master cylinder part by itself is only $50 cheaper than the whole assembly with new accumulator, pump, master cylinder, etc. - really, Toyota? Junk yard wanted $750 for used assembly with 210K miles on it, so maybe not such a great deal after all. My feeling is just go new and not have to worry about it for many more years (hopefully).
Can anyone provide details on how exactly to bench bleed the MC before bleeding the lines? I'm not sure if this is even really necessary, as the brake bleeding instructions in the FSM includes bleeding the Booster/Accumulator Pump Assembly (step 2) and the Master Cylinder Solenoid (step 4). For the MC solenoid bleed, I'm assuming this is the same as using the Techstream method to activate the ABS pump used to bleed the rear brakes (no "Intellingent Tester" required as per the intructions below)?
So, is it required to perform some other process to bench bleed the Master Cylinder also? I'd appreciate some help on how to do this if it should be done. Do you need some sort of MC bleeder kit to do so? First time doing this work, so appreciate the help. Asssembly removal and reinstallation process is pretty simple, so not worried about that part. Is the process pretty much the same as the manual bleeding of the brake line at the caliper (pump and hold brake pedal), but just cracking each brake line connection at the master cylinder until no air comes out?
Also, someone on another forum mentioned that it will it be necessary to have the Yaw Rate and Acceleration Sensor Calibrated. Is this true? If so, can it be done with Techstream, or will I have to bring this in to the stealership? I have had some weird issues recently where VSC will kick in shortly when I make a right turn going uphill, I wonder if this would resolve that issue too?
Thanks for the help!
BLEEDING
NOTICE:
• Wash off brake fluid immediately if it comes into contact with a painted surface.
• If the brake pedal is depressed with the reservoir cap removed, then brake fluid will spatter.
HINT:
• If any work is done on the brake system or if air in the brake lines is suspected, bleed the air from the
system.
• When bleeding, keep the amount of the fluid between the Min. and Max. lines on the reservoir.
1. FILL RESERVOIR WITH BRAKE FLUID
Fluid:
SAE J1703 or FMVSS NO. 116 DOT3
2. BLEED BRAKE BOOSTER W/ACCUMULATOR PUMP ASSEMBLY
HINT:
Perform this step only if the brake booster with accumulator pump assembly is removed and/or installed.
(a) Turn the ignition switch off, depress the brake pedal 20 times or more to release the pressure from the
accumulator (Procedure "A").
(b) Fully depress the brake pedal 10 times (Procedure "B").
(c) Turn the ignition switch to the ON position and start the brake booster pump (Procedure "C").
(d) Make sure the pump operates for 8 to 14 seconds.
If the pump does not operate as specified, repeat procedure "A" to "C" and recheck the operating time.
3. BLEED BRAKE LINE
(a) Front brake line
(1) Turn the ignition switch to the ON position and wait until the
pump motor has stopped.
(2) Connect the vinyl tube to the brake caliper.
(3) Depress the brake pedal several times, then loosen the
bleeder plug with the pedal held down (Procedure "D").
(4) At the point when the fluid stops coming out, tighten the
bleeder plug, then release the brake pedal (Procedure "E").
Torque:
11 N·m {112 kgf·cm, 8ft·lbf}
(5) Repeat procedure "D" to "E" until all the air in the fluid has
been bled out.
(6) Repeat the above procedures to bleed the other brake line.
BRAKE: BRAKE FLUID: BLEEDING; 2006 MY GX470 [08/2005 - ] https://techinfo.toyota.com/t3Portal/document/rm/RM00V0U/xhtml/RM...
1 of 3 2/7/2022, 5:27 PM
(b) Rear brake line
(1) Turn the ignition switch to the ON position and depress the
brake pedal.
(2) Connect the vinyl tube to the brake caliper.
(3) Loosen the bleeder plug and release air.
HINT:
Brake fluid is sent through the pump, so keep the brake pedal
depressed until the air is completely bled out.
(4) When the air is completely bled out of the brake fluid
through the bleeder plug, tighten the bleeder plug.
Torque:
11 N·m {112 kgf·cm, 8ft·lbf}
(5) Repeat the above procedures to bleed the other brake line.
4. BLEED MASTER CYLINDER SOLENOID
HINT:
Perform this step only if the master cylinder solenoid is removed and/or installed.
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Select "ACTIVE TEST" mode on the intelligent tester.
(d) Connect the vinyl tube to the rear brake caliper.
(e) Loosen the bleeder plug.
(f) Select "SRMF & SRMR" to drive the solenoids and bleed air from the rear brake caliper (Procedure "F").
NOTICE:
Do not depress the brake pedal.
HINT:
• Brake fluid is sent through the pump.
• To protect the solenoids, the intelligent tester turns OFF automatically 2 seconds after every solenoid has
been turned ON.
(g) Repeat procedure "F" until all the air in the brake fluid is bled out.
(h) When the air is completely bled out of the brake fluid through the bleeder plug, tighten the bleeder plug.
Torque:
11 N·m {112 kgf·cm, 8ft·lbf}
(i) Repeat the above procedures to bleed the other brake line.
(j) Turn the ignition switch off.
(k) Turn the ignition switch to the ON position.
(l) Clear DTC .
5. CHECK FLUID LEVEL IN RESERVOIR
