460 Brake Flush
07-22-14, 04:49 PM
#4
Lexus Fanatic
Here's my post from another thread:
"My Toyota dealer did this job for under a hundred bucks and even did a nice wash and vacuum of my car. All done in under 90 minutes while I drank their fancy cappuccinos and watched TV in their lounge."
Yes, Techstream IS required for this job. Otherwise, it sets off all kinds of brake system errors.
"My Toyota dealer did this job for under a hundred bucks and even did a nice wash and vacuum of my car. All done in under 90 minutes while I drank their fancy cappuccinos and watched TV in their lounge."
Yes, Techstream IS required for this job. Otherwise, it sets off all kinds of brake system errors.
07-22-14, 05:13 PM
#5
An independent Toyota/Lexus specialist told me they use conventional vacuum bleeding for servo brake systems on both Toyota and Lexus that have it. A techsstream is needed for new servos or if the reservoir runs dry and air gets in the system. A tech at the Lexus dealer told me the exact same thing. Had the brakes vacuum bled on my '07 LS and it worked fine. Surprisingly, the old fluid didn't look bad after 51k miles and seven years.
07-22-14, 08:21 PM
#6
Advanced
Thread Starter
An independent Toyota/Lexus specialist told me they use conventional vacuum bleeding for servo brake systems on both Toyota and Lexus that have it. A techsstream is needed for new servos or if the reservoir runs dry and air gets in the system. A tech at the Lexus dealer told me the exact same thing. Had the brakes vacuum bled on my '07 LS and it worked fine. Surprisingly, the old fluid didn't look bad after 51k miles and seven years.
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07-23-14, 04:30 AM
#8
Driver School Candidate
Mods - Feel free to delete this post if you feel this infringe copyright laws.
In essence, bleeding brakes in the LS is not a simple procedure and Techstream is needed if done properly.
The brake bleed procedure consists of 5 main sections:
^ Section 1: Zero Down Accumulator Pressure (Zero Down)
This procedure is used to release the pressure from the accumulator prior to bleeding the brakes (or replacing the brake actuator). Techstream is used for this procedure.
^ Section 2: Disable Electronic Controlled Brakes (ECB Invalid)
This procedure using Techstream disables the ECB system temporarily to allow the front brakes to be bled manually. Using Techstream to disable brake control causes the master cylinder cut solenoid to turn OFF and the line from the master cylinder to front brake calipers to open allowing manual bleeding of the front brakes.
^ Section 3: Front Brake Bleed - Manual Process
This is a two-man process in which one technician pumps and holds the brake pedal while another technician opens the right front bleeder screw to remove air from the system. The same procedure is repeated for the left front.
^ Section 4: Rear Brake Bleed
^ Right Rear Brake Line Air Bleed
During this procedure Techstream opens the solenoid for the right rear brake line and then the accumulator pump runs during this process to push fluid and air out of the right rear caliper bleeder valve. During this process the brake pedal is NOT applied - the accumulator pump will automatically pump fluid out of the right rear caliper bleeder valve. This process bleeds the red brake line (suction line from the accumulator to the actuator) and passes air out through the right rear caliper bleeder.
^ Left Rear Brake Line Air Bleed
The left rear brake line is bled using a combination of the brake pedal being pressed-and-held and the accumulator pump.
^ Section 5: Reset Memory and Linear Valve Offset Calibration
The purpose of this step is to erase all previously memorized brake actuator linear valve calibration values and to re-calibrate the brake actuator linear valves after all brake bleeding procedures are finished. This procedure resets the memory of the skid control computer and then performs the Linear Valve Offset Learning Process. During the Linear Valve Offset Learning Process the skid control computer memorizes the characteristics of the actuator linear solenoids.
In essence, bleeding brakes in the LS is not a simple procedure and Techstream is needed if done properly.
The brake bleed procedure consists of 5 main sections:
^ Section 1: Zero Down Accumulator Pressure (Zero Down)
This procedure is used to release the pressure from the accumulator prior to bleeding the brakes (or replacing the brake actuator). Techstream is used for this procedure.
^ Section 2: Disable Electronic Controlled Brakes (ECB Invalid)
This procedure using Techstream disables the ECB system temporarily to allow the front brakes to be bled manually. Using Techstream to disable brake control causes the master cylinder cut solenoid to turn OFF and the line from the master cylinder to front brake calipers to open allowing manual bleeding of the front brakes.
^ Section 3: Front Brake Bleed - Manual Process
This is a two-man process in which one technician pumps and holds the brake pedal while another technician opens the right front bleeder screw to remove air from the system. The same procedure is repeated for the left front.
^ Section 4: Rear Brake Bleed
^ Right Rear Brake Line Air Bleed
During this procedure Techstream opens the solenoid for the right rear brake line and then the accumulator pump runs during this process to push fluid and air out of the right rear caliper bleeder valve. During this process the brake pedal is NOT applied - the accumulator pump will automatically pump fluid out of the right rear caliper bleeder valve. This process bleeds the red brake line (suction line from the accumulator to the actuator) and passes air out through the right rear caliper bleeder.
^ Left Rear Brake Line Air Bleed
The left rear brake line is bled using a combination of the brake pedal being pressed-and-held and the accumulator pump.
^ Section 5: Reset Memory and Linear Valve Offset Calibration
The purpose of this step is to erase all previously memorized brake actuator linear valve calibration values and to re-calibrate the brake actuator linear valves after all brake bleeding procedures are finished. This procedure resets the memory of the skid control computer and then performs the Linear Valve Offset Learning Process. During the Linear Valve Offset Learning Process the skid control computer memorizes the characteristics of the actuator linear solenoids.
Last edited by Vvman; 07-23-14 at 08:09 AM.
07-23-14, 05:18 AM
#9
07-23-14, 05:20 AM
#10
Advanced
Thread Starter
[QUOTE=Vvman;8637802]Mods - Feel free to delete this post if you feel this infringe copyright laws.
In essence, bleeding brakes in the LS is not a simple procedure and Techstream is needed if done properly. {end quote}
Are you for real??? This is what car forums are about.
In essence, bleeding brakes in the LS is not a simple procedure and Techstream is needed if done properly. {end quote}
Are you for real??? This is what car forums are about.
07-23-14, 06:19 AM
#11
Lexus Fanatic
Are you for real??? This is what car forums are about.
That said, thanks VVMAN for the info!
07-23-14, 06:33 AM
#12
Advanced
Thread Starter
FWIW, he's the only one depicting service manual info that I have seen. This is just a discussion about brake fluid flushing.
07-23-14, 07:26 AM
#13
Lexus Fanatic
07-24-14, 04:50 AM
#14
Advanced
Thread Starter
Regarding OEM, or any shop manual for that matter, anyone who has used them to any extent knows they are not always accurate. I traded a Mercedes CL500 for my current 460 and the shop manual was clear regarding necessary tools to bleed the brakes, including using the Mercedes Star Diagnostic scanner. I talked to a Mercedes tech about it and he said you don't need the tool and that the brakes could be gravity bled to accomplish a flush. Same goes for my '91 Lincoln. The brake system on this car is under approx. 3000 psi. Now if you open one of the bleeders with this amount of pressure, you are going to create some problems. Obviously the pressure must be first released before opening the system and then you can bleed the brakes manually.
OEM shop manuals are written by engineers who I doubt ever lifted a wrench to the cars about which they provide detailed repair/maintenance procedures. Again, if you've used such manuals, you know this. But of course we still need them as they are an excellent resource and by far the best available. Dealers use OEM on line systems which are constantly being updated for various changes. When I purchased my '11 460 last year, I was able to get the OEM shop manuals, 7 volumes, thru the dealer for just $500. Sound like a lot; they retail for over $1500 (yikes), plus shipping and handling. (Just my 2 cents)
OEM shop manuals are written by engineers who I doubt ever lifted a wrench to the cars about which they provide detailed repair/maintenance procedures. Again, if you've used such manuals, you know this. But of course we still need them as they are an excellent resource and by far the best available. Dealers use OEM on line systems which are constantly being updated for various changes. When I purchased my '11 460 last year, I was able to get the OEM shop manuals, 7 volumes, thru the dealer for just $500. Sound like a lot; they retail for over $1500 (yikes), plus shipping and handling. (Just my 2 cents)
07-24-14, 06:06 AM
#15
Regarding OEM, or any shop manual for that matter, anyone who has used them to any extent knows they are not always accurate. I traded a Mercedes CL500 for my current 460 and the shop manual was clear regarding necessary tools to bleed the brakes, including using the Mercedes Star Diagnostic scanner. I talked to a Mercedes tech about it and he said you don't need the tool and that the brakes could be gravity bled to accomplish a flush. Same goes for my '91 Lincoln. The brake system on this car is under approx. 3000 psi. Now if you open one of the bleeders with this amount of pressure, you are going to create some problems. Obviously the pressure must be first released before opening the system and then you can bleed the brakes manually.
OEM shop manuals are written by engineers who I doubt ever lifted a wrench to the cars about which they provide detailed repair/maintenance procedures. Again, if you've used such manuals, you know this. But of course we still need them as they are an excellent resource and by far the best available. Dealers use OEM on line systems which are constantly being updated for various changes. When I purchased my '11 460 last year, I was able to get the OEM shop manuals, 7 volumes, thru the dealer for just $500. Sound like a lot; they retail for over $1500 (yikes), plus shipping and handling. (Just my 2 cents)
OEM shop manuals are written by engineers who I doubt ever lifted a wrench to the cars about which they provide detailed repair/maintenance procedures. Again, if you've used such manuals, you know this. But of course we still need them as they are an excellent resource and by far the best available. Dealers use OEM on line systems which are constantly being updated for various changes. When I purchased my '11 460 last year, I was able to get the OEM shop manuals, 7 volumes, thru the dealer for just $500. Sound like a lot; they retail for over $1500 (yikes), plus shipping and handling. (Just my 2 cents)
That 3000 psi is the pressure in the accumulator and is used to boost brake line pressure only when the brake pedal is pushed. I think this is why your Mercedes says gravity bleed and my Lexus techs say vacuum bleed. Neither method involves pumping the brake pedal with an open bleeder. That must be a no-no with servo brake systems.
