Brake fail after replacing brake lines

[mark0]

Lads replaced brakes lines with copper lines bleed the system no leaks then when road tested I have no brakes

did I miss something 

 

[xzirri]

How is the brake pedal position? Have you checked the brake fluid level? Does the pedal "harden" when you pump it while the engine is off, then depress when you start the engine?

EDIT: Sounds like there might still be some air trapped in the brake system, how did you bleed it?

[mark0]

Yes it gets hard and then depresses

[mark0]

The 2 man system on pumping pedal and me turning bleed nipple on each wheel

[mark0]

I have a pressure bleeder but I can’t remove filter in master cylinder it seemed to be wedged in

[xzirri]

If you press the brake pedal with the engine running, does it travel all the way to the floor after a while? Also, did you close the bleed nipple while the brake pedal was depressed, or did your mate let go of the pedal too early?

[xzirri]

If the pedal drops all the way to the floor then you most likely have air in the brake lines and need to bleed it again. If not then I'm out of suggestions, maybe someone else knows something more?

[mark0]

Thanks mate

[mark0]

Does any body know if little filter inside master cylinder does it come out it seems to just spin around I don’t want to brake it I need to remove it to put pressure bleeder on 

[mark0]

Just an update still joy bleed all whees again Pedel  gets hard when you start the engine pedal goes limp to the floor and no brakes

[xzirri]

Seems like you still have air in the brake lines. Try this: Close the bleeder nipple, tell your friend to pump the pedal a few times and hold the pedal pressed down, open the bleeder nipple and close it again when there's no air coming out. Repeat this a few more times. Make sure the master cylinder reservoir doesn't go empty, as that would suck more air into the system.

[mark0]

Does anyone know the correct bleed sequence for avensis 

is it rear driver rear passenger  then passenger the driver it’s a right hand drive 

cheers 

 

[xzirri]

If the brake cylinder is on the passenger side, then you should do rear driver side -> rear passenger side -> front driver side -> front passenger side. Thought is that you should bleed from farthest to nearest in relation to the cylinder.

[mark0]

Thanks mate 

[xzirri]

You're welcome! Let us know if you get it sorted out!

[mark0]

I will be doing it in the morning I will post update 

thanks mate 

[Konrad C]

A few years ago, I successfully bled the brakes of my old Avensis using the Gunson Easibleed pressure bleeding kit. I set the pressure to about 25 psi after trying 15 psi. I went to each wheel and went around until the new fluid came through. I started at the wheel furthest from the master cylinder. The result, good responsive pedal. I worked on my own so this was the only way I could get the job done. Anyway I tried pumping the pedal route with an assistant a few years earlier, and it did not work. The pedal was soft and had long travel. That is when I first got the pressure bleeding kit. It is easier and faster.

[Bob110023]

Some cars still use a pressure regulating valve on the rear brakes. This allows for different weight scenarios in the back of the car. If this is fitted you need to have at least two adults sat in the back when bleeding the rear brakes, this opens up the valve more. Worth a check. Good luck mate

[mark0]

Lads thanks for reply’s I went from having no brake right after bleeding with pressure bleeder. The pedal travels all the way to the floor. The  brakes only started  to work after I bleed the master cylinder by cracking the the 2 nuts on the pipes going in to it I think I have an air lock in master cylinder or abs system as I have no proper brakes and excessive brake travel I have bleed  the brakes 3 times with Draper pressure bleeder extracting and flushing approx 2 liters of brake fluid with no bubbles in it I think I could have a master cylinder problem when brake pedal is depressed and pumped by another person in the car you can her a squelching sound from master cylinder with your head under the bonnet and the say that if you set pressure bleeder to 2 bar leave it connected for 10 mins and recheck if pressure doesn’t drop you have no leaks if it does you have a leak we’ll no pressure drop and no leak it’s a mystery 

[Mike169]

Hi Mark.

Sounds like you are having troubles mate.

I have worked in many garages and some don't do the pushing the pedal to the floor to bleed as the piston and seals in the master cylinder itself travel much further along the master cylinder itself and often there is debris and even rust at the previously unused say last 2mm of the bore of the cylinder which has the effect of ripping/scoring the seals of the master cylinder piston and the only way out is if you are lucky fitting a new seal kit to the master cylinder piston itself but to make sure it doesn't happen again a garage may simply just fit a brand new master cylinder so you then know the 'pump' is 100% working properly.

Another option is just undo the 4 bleed nipples and let them drip for say 5 minutes as this is an alternative way of bleeding the brakes and a bit late now but if this was done first then this way cannot damage the seals on the master cylinder piston itself...…...this way is still worth trying now to see if things improve. Don't do this on your tarmac drive if you have one as it will destroy the tarmac itself, tarmac and brake fluid don't mix.

You can also try making 2 or however many 'exists' you have from your master cylinder short brake pipes and blanking the ends off and see if the brake pedal still sinks, if it does then the master cylinder is either faulty or has air in it.

Good luck, Mike

[mark0]

Thanks mike i will give it a go and post update 

[mark0]

Just an update lads bleed again brakes a little better brakes work but pedal still to much travel in it for a nct pass I think abs module has air in it and might need to be bled with a scan tool 

[xzirri]

Tough luck mate! Aren't those tools quite expensive? If your brakes are working good enough to engage the ABS system you could do a couple of hard brakes to force the ABS module to cycle the air out of the modules. Might be tricky to do though. If you should decide to do so, make sure you take sufficient safety precautions.

[mark0]

Thanks mate will give it a go anybody know a scanner that can bleed abs on avensis my mate has one but not compatible with avensis

[mark0]

Lads update had to leave it in to get done the mechanic said 2 huge bubbles of air came out at each front wheel when he blead it 

it fixed the spongy pedal and it passed retest on nct

question is when I bled it 3 times and got a lot of air out it didn’t fixed the pedal going to the floor don’t no if mechanic blead it with computer or not but it is fixed now