Air in Master Cylinder Help!

[TONEDOG513]

Hey guys!

2 years ago did my brakes with a friend, we accidentally let the master cylinder suck some air. Finished the job and pedal was never really the same

Flushed the fluid many times since then to no avail and pads are still at 6mm today.

If I double pump i get the pedal feel that i once had, I feel like the rears are doing all the work as I have done new pads 2x on the rear vs the fronts are still like new.

Today finally got around to dropping it off at the dealer, I asked specifically for them to use the tis and actuate the master cylinder and bleed it.

I dropped at 730am got it back at 430pm and I can't even tell that they did anything. I asked to speak with the tech and he was gone at 4pm.

So tomorrow I'm gonna go over there and speak with the tech "John" to ask exactly what he did as the advisor didn't really get it.

My questions to you guys

1. how do I know they did it?
2. What should I ask?
3. Can they have really done it and what I think is a pedal that sinks half way before engaging Nirmal?
4. Should I waste more money and tey another shop?

I paid for a brake diagnostic, 186 plus tax if that means anything to ya.

Any advice would help.

Best,
Tony

 

[AuSeeker]

Hey guys!

2 years ago did my brakes with a friend, we accidentally let the master cylinder suck some air. Finished the job and pedal was never really the same

Flushed the fluid many times since then to no avail and pads are still at 6mm today.

If I double pump i get the pedal feel that i once had, I feel like the rears are doing all the work as I have done new pads 2x on the rear vs the fronts are still like new.

Today finally got around to dropping it off at the dealer, I asked specifically for them to use the tis and actuate the master cylinder and bleed it.

I dropped at 730am got it back at 430pm and I can't even tell that they did anything. I asked to speak with the tech and he was gone at 4pm.

So tomorrow I'm gonna go over there and speak with the tech "John" to ask exactly what he did as the advisor didn't really get it.

My questions to you guys

1. how do I know they did it?
2. What should I ask?
3. Can they have really done it and what I think is a pedal that sinks half way before engaging Nirmal?
4. Should I waste more money and tey another shop?

I paid for a brake diagnostic, 186 plus tax if that means anything to ya.

Any advice would help.

Best,
Tony

Before you take it to anyone else or do or try anything else you need to do/try the "40 pumps" procedure, here's a link to a recent topic with similar symptoms as to what you have, I posted (post #3) a link to another topic that has the "40 pumps" procedure PDF from Toyota, may just solve your problem for free, it has for numerous members here, the dealer's Tech may have done this but you never know, sometimes they don't look at their own Shop Manuals if they think they already know it all, and you can do this yourself and you should after every time you bleed your brakes!

Brake Pedal travel question

 

[TONEDOG513]

Auseeker

Thank you for my only reply!

At the dealer I had them get me the tech, he assured me he used the teacstream solenoid actuated process and there is definitely no air in the system.

I also tried your recommendation a few times already to no avail. :/

I do have a question, that day we did the "big brake job" and sucked in that air. I replaced the calipers for 5th gen's (2010's to be exact) They were supposed to help with the constantly freezing caliper issue we all face.

I just read this interesting post about brakes and master cylinder/caliper piston sizes. Essentially he was saying the bigger the caliper piston the more spongy/less firm and vs versa. I wonder should I go back to the smaller 4th gen caliper??

I also did new brake hoses that day. Raybestos BH382878 Professional Grade Hydraulic Brake Hose to be exact. They look really nice, hood quality. I wonder should I go to stainless steel?

Oe. Pads are ceramic, maybe a semi metallic will bite better?

The fronts seem to barely working compared to the rears, unless I double pump. I wonder if the systems is sending out the same pressure to all 4 calipers, the rears are smaller bore and the front are bigger rhat the bore size difference is yielding a miss match in applied pressure resulting in a car that basically is only using the rears.

Am I crazy?

Best,
Tone

 

[AuSeeker]

I'm not sure what else to tell you to try, most solve this issue with the 40 pumps.

Many have done the 5th Gen upgrade and I haven't heard of but 1 or 2 complains of a difference in pedal feel and that could be just a little air in the system.

The 40 pumps have to be done very slowly and with the switch off or it doesn't help from what all I have read about it.

Edit: Just a long shot but just remembered I have read about a couple of owners got rid of the air in the ABS system by doing numerous "panic" stops to make the ABS system to activate which opens the ABS valves allowing any trapped air to move passed the valves, I guess it worth a shot, if it works it means the Toyota Tech didn't do a very good job when he bled the system.

 

[bob3dsf]

5th gen brakes solve frozen caliper?

1. do you know anyone with a code scanner that can bleed ABS systems? Supposedly there are many now that have the functionality to actuate the ABS solenoids. Mine does, but I haven't tried to use that feature yet.


2. solving the frozen calipers (just a few thoughts since you mentioned it): Do the 5th gen calipers really do this? Unless there is some design change, I don't see how it's possible. I believe that it's really just a maintenance issue, although it's maintenance that most people never do. I think that over time, the dust boots get dry and crack with the heat associated with the brakes, then this allows moisture in to the cylinder bores, and then corrosion... add winter road treatment to the mix....

I feel like a regular check of the dust boot conditions and then rebooting should keep the frozen caliper away. But, most never check that and then just swap calipers when they freeze up. The reboot and reseal process is pretty easy and it seems more than reasonable that this is the only way to truly eliminate the frozen caliper issue.