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mflorant

Brake pedal/braking

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Hi all! (2009 T27 CVT 2.0)

My brakes are behaving a bit strange. When braking I feel that I need to push the pedal almost to the bottom to have some brake power. So when I push the pedal it is not really having brake power on the top only starts braking lower. When slowing the car discontinuously slows down. 

There is no air or leakage in the system, I have checked so far. Brake pads and discs are new.

I am clueless, any suggestions? 

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A few questions -

This is a problem that started when the disks and pads were replaced?

Were the rear pads replaced or just the front?  Was this a job you did yourself? 

How did you establish that there is no air in the system?

The extra brake pedal travel sounds like a brake pad or caliper has some 'spring' in it because it is not aligned properly to the disk after putting it back together, so the pressure on to the pad is not being evenly applied across its friction surface.  One or more of the pads is not properly seated, or less likely, the caliper is not seated properly on its mounting.

I have heard some people have suffered master cylinder rubber seal problems, after forcing back brake fluid to the master cylinder during pushing back of the brake caliper pistons.  Apparently, draining the excess fluid at the caliper bleed nipple, rather than pushing it back into the master cylinder, can prevent this risk.  I have never suffered this myself, though.

Hopefully, other posters will have some other ideas.

 

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When describing the brake pedal movement and feel, does the pedal need a lot of force or a lot of travel, or a combination of both?

You said the brake pads and discs were replaced recently. Did the problem start from then? Brakes need a little running in time. I just changed my front brake pads recently and the bed in after a while - they were fine a couple of days later. The pedal was firm but more force was needed. Now gentle press and the bite is back.

Hopefully the new discs faces were cleaned of any protective grease before installation!
Other things like checking that everything has been installed properly, the brake caliper clean and copper grease at certain points, the sliders have free movement.
Go over everything. 

 
 

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When I bought the car the discs and the pads have been changed. I only did the bleeding, when I have still felt braking is not like it was on my previous cars.

Checked the sliders, put brake grease on it.

The pedal needs a lot of force and a lot of travel.
 

My main problem is that there is no "bite" effect 😔

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When you bled the brakes, did you use a pressure bleeding system? Also the T27 supports ABS bleeding using Techstream or suitable diagnostic software. 
The 'bite' tells me that the vacuum pump, piping and servo may need checking, and flexible brake pipe could be damaged, or the brakes need to be bed in or discs not cleaned before installation, contaminating the the pads. Contamination can may result in glazed disc and pads, meaning less friction and no stopping power! Did you know who fitted your brakes? 

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No pressure system used for bleeding.

I have realized that when I am pushing twice the pedal I am having the "bite" effect.

Btw discs and pads were cleaned by myself. I also had a guess that this may cause the issue.

Does this give you some more clue?

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1 hour ago, mflorant said:

No pressure system used for bleeding.

I have realized that when I am pushing twice the pedal I am having the "bite" effect.

Btw discs and pads were cleaned by myself. I also had a guess that this may cause the issue.

Does this give you some more clue?

There is no leakage of Oil, the level doesn't change in the canister. 

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Hi! Maybe what i am going to say doesn't have to do with the problem but maybe could be.

If you keep the brake pedal depressed, do you gradually lose the braking power? For example, standing in a redlight or something. I'm asking this because my brother had a similar problem few years ago and was the pump that slowly was loosing pressure due to worn seals.

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On 1/29/2020 at 11:24 AM, mflorant said:

I have realized that when I am pushing twice the pedal I am having the "bite" effect.

This suggests air in the system. Try vacuum bleeding..

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On 1/29/2020 at 1:44 PM, doc_14 said:

Hi! Maybe what i am going to say doesn't have to do with the problem but maybe could be.

If you keep the brake pedal depressed, do you gradually lose the braking power? For example, standing in a redlight or something. I'm asking this because my brother had a similar problem few years ago and was the pump that slowly was loosing pressure due to worn seals.

Actually I haven't had such an experience with mblockquotelockquote widget

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I bought a vacuum bleeder, so I will try my best.

Will write my experiences.

Thanks for everything! 

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When pressure bleeding, you may need to go gentle, say 15-20 PSI, and go around to each wheel. After the first round of bleeding the pedal doesn't or improves slightly, raise the pressure to say 25 PSI or a little higher and do again. Two benefits are new clean brake fluid with air and contamination removed. 
The servo assistance check is done by pressing the pedal with the engine off. The pedal will sink and be firm. When the engine is on, the pedal will not sink as low, and the bite should be good with not much force. When you stamp on the pedal, the car should brake sharply, and if a wheel loses grip, the ABS kicks in.

I look for to ready your outcome. 👍   

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Dears,

I did the vacuum bleeding, the brake became slightly better.

The discontinuity is still on, but I can feel it less. Is somehow the CVT also affecting braking or not?

Or my new brake pads are sh@#$t.

Any further suggestions?

Ps.: I have checked all the hoses, no leakage or trickle

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We had front discs and pads replaced by a dealer on our old Corolla some years ago. It was absolutely fine for several weeks including a holiday in the Isle of Man which saw some pretty heavy brake action (70MPH roads and steep steep descents). All good. Came off the ferry and a couple of miles in and the pedal went nearly to the floor. Next application was OK, then same again. Lightly touching the pedal first and then applying the brakes saw them work each time.

The dealer looked at it the next day and apologised and said the problem was in fact residual air in the system and that the brakes could in some circumstances be extremely difficult to bleed correctly sometimes. That was seven years ago and its been trouble free since.  

    

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So back again.

Did bleeding with the vacuum thing again, not much happened...

I have serviced my brakes, meaning that I have removed everything at the front brakes, cleaned, greased where it is needed, discontinuisity is gone! I think the pads were locked, not well sliding.

I realized that I have to change the brake pads very soon and I also realized that I have two different brake pad brands on the left and right hand side...

Which brand do you recommend for pads? I was thinking about Bosch.

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15 hours ago, mflorant said:

So back again.

Did bleeding with the vacuum thing again, not much happened...

I have serviced my brakes, meaning that I have removed everything at the front brakes, cleaned, greased where it is needed, discontinuisity is gone! I think the pads were locked, not well sliding.

I realized that I have to change the brake pads very soon and I also realized that I have two different brake pad brands on the left and right hand side...

Which brand do you recommend for pads? I was thinking about Bosch.

I re read the post and comments and correct me if I am wrong with order of events. 

  1.  Lorant the OP, says the brakes pedal has a lot of travel, and the car just had the brakes changed.
  2. Lorant confirms the disk and pads were changed before he bought the car.
  3. Lorant has checked the sliders, put brake grease on it.
  4. The pedal needs a lot of force and a lot of travel. 
  5. Lorant bleeds the brakes after, using the manual pressing the pedal method. Not pressure bled.
  6. Also clean the disks and pads - sure during or after brake pad replacement!
  7. Confirms there are no leaks.
  8. Buy and uses vacuum bleeder which improves the pedal, but not to Lorants satisfaction. (doesn't say make of vacuum bleeder)!

Lorant queries the quality of the brake pads. I mention that brakes always need running in after replacement. I find they don't work well at the beginning.
And now Lorant has posted the quoted update. I am confused a little?

What brakes were changed and when? Normally changing brakes front and rear involves replacing the disk (clean off protection Oil) and pads, and any other preparation. After replacing the brakes, the pedal has to be pumped two or three times to set the pads and get the pedal to normal. Some people when changing the brakes, open the bleed nipple to assist compressing the piston back. The last time a friend did that method, he had no brakes and it took a while to bleed the brakes! 

Then for up to 100 or so miles, the brakes won't feel sharp and brake pedal will need a little more force, as they bed in! This means slowing earlier and gently.
Now in the last post Lorant says there are two different brand of brakes left and right! Sound like a dodgy mechanic has done some dangerous work. need some photos to help explain what is going on.

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Dear Konrad,

Thank you for the listing, it is very correct. Sorry for being a little bit confusing, but service after service I was realizing things and differences.

I am definitely going to change the pads and then we'll see if there is any improvement or not, hoping the best.

Thanks again!

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Hello Lorant,

Once you have cleaned  and replaced the brake parts, pump the pedal until it is high. It should take 2 -5 pedal presses. Also if the rear pads and disks have been worked on, operate the parking brake a few times. Also as a warning view the pads and remove them and inspect the inner pad and piston. The reason I mention this, is if the piston when wound back the slots are not horizontal, the caliper won't slide back easily, plus the pin on the rear of the inner brake pad should be with the slot, not on the piston face! This will cause the pad the wear unevenly to one side, and cause the go to one side and affect braking. That's what happened to me. See my post below. 
Now once you have checked the pedal feel with the engine off, and decide if you need to bleed the brakes. If you are happy with the pedal, turn on the engine and then check the pedal again. It should be higher when the servo is working. You car like mine being Valvematic, uses a vacuum pump which you can hear making a tapping sound at idle. If the brake pedal didn't kick up, and you need a lot of force, the vacuum system to the servo is your next item to check! Let's hope you don't need to go that far. 👍
 

 

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If the OP is saying there are two different brands of pads on the front axle then that's very odd because pads are only ever sold as complete sets.  Somebody has being messing about with the brakes. If it were my car I would replace front discs and pads and re-bleed. Check the slide pins are free and the rubber boots intact.

Any recognised brand would be fine (Bosch, Mintex, Textar etc etc).

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On 2/20/2020 at 2:09 PM, mrfixer said:

If the OP is saying there are two different brands of pads on the front axle then that's very odd because pads are only ever sold as complete sets.  Somebody has being messing about with the brakes. If it were my car I would replace front discs and pads and re-bleed. Check the slide pins are free and the rubber boots intact.

Any recognised brand would be fine (Bosch, Mintex, Textar etc etc).

I am not sure about legal side of maintenance of brakes, but I remember a case where a man killed his children, because he only changed the brakes on one side! That is why brake pads are sold as axle set. I hate that sellers price the disks individually, though all the places I know sell them as axle pairs.     

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Hi

I am going to change my front and rear pads very soon. I am going to purchase Brembo, it seems it has a very good price and quality combo.

I am going to update my previous experiences after changing them

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You are correct, Lorant, Brembo are a quality company.

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Lorant once you have done the pads etc  if it does it still I totally agree with Konrad

My VVTI had horrendous problems with brakes when I bought it.  It couldn't even drive me home.... It continued really as all of the brake components including the pipes and a caliper  were replaced.  Sadly when it comes to calipers there are so many different ones it may have on the 2001 Avensis... 6 actually!  Its better to get new than scrap for them as it has to be the right one.

I had to do discs and pads all round but also it was the servo.. I got a s/h one from a donor car but by the time she came off the road for good that servo was in need of at least the piston replacing. 

It intermittently had a too much travel on the pedal, we bleed it. I have to have help as I found the self bleed kits didn't get all the air out. It continued. We bleed it again but it was the servo.

The last time she went on the road she played up... It was the s/h servo and it bit about 4" from the bottom.... it then made a noise.  The pedal juddered to...  It felt like you were walking on uneven gravel if that makes sense?

I knew that was her last drive bless her, she was only 4 weeks from her mot  and we knew she was not being re mot'd as she could not have any more welding..... She may not have needed it but I had paid 100's every mot and her brakes were the last straw ... 

If replacing the disc etc doesn't cure yours get the servo checked . Mine was working fine till it did that juddering but the brakes were not as good as they usually were though had I not known the car I may not have noticed they were not 100% 

Sadly to many second hand cars have had bodge jobs done on them  but when it comes to brakes you must do both sides and the person that did the odd ones on yours was totally out of order! 

I really hope yours is sorted easily and once done its all cured. 

 

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Another plus: when I start the car after a night parking in the garage, and I start rolling the car a metal on metal knock sounds. It is only once and it comes from the left wheel. Can this knocking be also related to my issue?

Ps: in the back when I'm braking there is also a click coming from the left rear wheel.

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Lorant my old girls caliper knocked just  before it broke.

Sadly a few things can cause a knock in the front but in your shoes if it were my car I think I would get a garage, a mechanic or someone with experience that can look and know what it is  to check it and see exactly what is going on.

Mine had so many problems with brakes but it grouched rather than clicked.  I had a bit of uneven pad wear on the side the caliper broke but that caliper knocked three times before it locked up totally.  Then it pulled and dragged badly. Thankfully it happened just at my gateway. 

Someone here may be able to advise you but honestly if that was my car I would get it properly checked and not use it till I knew what it was.... 

It may only be metal to metal cos the pad is unevenly worn, the brakes are binding for some reason or the pads are not in the right place etc but it could be the caliper or anything really.

My old Avensis only specialised in brake and welding problems but long ago I had one knock on the front and it was  ball joint with a worn bearing to boot.

I promise you if one of mine did that I would be asking the garage to check it over.

Fingers crossed its nothing bad but in your shoes I would get it checked to find out what it is. 

 

 

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