Edmunds dealer partner, Bayway Leasing, is now offering transparent lease deals via these forums. Click here to see the latest vehicles!
Options
Need the site for repair manual subscriptions
Earlier this year I saw somewhere in Edmunds how to go to a website that had "repair manuals" digital that you could subscribe to. A broken wrist had kept me from following up on the work until recently. However, I can't find that site now.
I need to fix the brake pedal travel on a 2014 Toyota Sienna LEX (?) minivan. The brake pedal inconstantly slowly sinks down to the floor usually about 30 seconds after waiting with your foot on the pedal like at a stop light. Five Toyota techs have witnessed this but because the computer says nothing is wrong, Toyota will do nothing. For your information, the computer tester can't see any problem because there is no pedal position sensor and pressure inputs on the brake pedal side of the system. It will need the human eyeball and experienced brake technician. I need to copy the manual pages to see if I can make a repair or give it to the local garage mechanic to fix.
I need to fix the brake pedal travel on a 2014 Toyota Sienna LEX (?) minivan. The brake pedal inconstantly slowly sinks down to the floor usually about 30 seconds after waiting with your foot on the pedal like at a stop light. Five Toyota techs have witnessed this but because the computer says nothing is wrong, Toyota will do nothing. For your information, the computer tester can't see any problem because there is no pedal position sensor and pressure inputs on the brake pedal side of the system. It will need the human eyeball and experienced brake technician. I need to copy the manual pages to see if I can make a repair or give it to the local garage mechanic to fix.
0
Answers
If you just want to start with wiring schematics, bbbind.com has those for free.
To try and prove what is going on, I'd recommend someone get plugs to block sections of the brake system off. Start by first blocking one port of the master cylinder leaving half of the system operational, then switch by reconnecting that half of the system and block off the other half. If there is some kind of internal leakage say in the ABS system, the pedal will still sink when that half of the system is operational and not sink when it is blocked off. If both master cylinder ports are blocked off and the pedal still sinks then the master cylinder itself is suspect.
ABS systems use accumulators inside the assembly to allow brake apply pressure to be bled off if a wheel is locking up. These accumulator piston bores usually have a small passage that leads to the outside of the unit that is blocked off with a removable rubber plug. If the port is accessible in the car, a technician can remove that plug, insert a tool through that port and touch the backside of the accumulator piston. Now if someone else pushes on the brake pedal the tech can observe if the accumulator piston is being pushed by fluid leaking past the dump valve. Any pistons being forced down their bores require the ABS control valve assembly to be replaced as they are not serviceable separately. This is a very rare failure if it is occurring. As in the case of those gages, a thousand technicians can go their entire careers and never even need to know this test is possible let alone have to do it. Then you have the problem that with how and where the ABS controls are often mounted in the vehicle it may be impossible to access the test ports to even try and do this test. This results in a lot of people just deciding to swap the unit out as a test, since trying to remove the unit and make some kind of a rig to test it would be very impractical. Then we have the little problem that nobody wants to be the person paying for all of the testing that might need to be done, which means if a tech does take this on he/she isn't being paid to do it, no matter how much time they invest.
Also, you might consult with a Lemon Law attorney in your state, since there have been, apparently, numerous attempts to fix this problem.
I used to be able to go to a digital repair manual for my Hyundai, but then they first started charging a 'subscription fee' and no eliminated the service all together. Earlier this year Toyota had a similar subscription manual but now it too is gone. During my search, It became obvious that all car manufacturers were doing the same thing beginning about 2014.
I have filed the problem with NHTSA and probably will need to wait 10 years for them to get around to investigating it.
I'm still having trouble understanding how a factory tech can witness a brake pedal going to the floor and not authorizing a repair.
Shortly before, I took it to another Toyota dealer and was told nothing was wrong and to come back if it happens again. A block away, it did it at a stop sign. I drove right back and the service rep went for a test ride with me. Nothing happened until we returned and as he was getting out the pedal dropped......and he saw it happening. He immediately drove it in to the brake tech. The result.....can't find anything wrong.
At that point There were stories of similar brake problems at Ford. Is it possible that Toyota and Ford use a common brake part similar to many cars using air bags from a common supplier?
I want to do the repair but need the service manual illustrations, diagrams, etc.. In all other respects this is a wonderful van.
1 I have noted that many new cars brakes work better after bleeding them. As an engineer familiar with production practices, my guess is that pouring the fluids during producing the brake fluid entrains air. Result the spongy brake feel.
2 The only variable possible for the pedal dropping is in the vacuum booster. My guess is that it is a faulty check valve or hose leak.
Terrible weather to work under the hood. Will get back at some time but don't know when.