Sorry Brakes Again "SOLVED"

[cab262]

Hi guys am almost certainly in the Doo Doo here, recently I changed the NSF flexi hose,,Disc's & Pads on my 2004 1.9 tdi after many hours of messing around I managed to get a hard pedal,, I only wish I had looked here first !!

My problem is that now the front brakes are binding but if you hook your foot under the pedal and lift up,, it releases the binding problem.

Question 1 Have I knackerd the master cylinder by bleeding the conventional way " Inverted seals"

Question 2 Can you take apart the master cylinder and refit the seals correctly

Question 3 I have borrowed an early vag com cable to possibly bleed abs pump but I'm not sure if my car is OBD11 or CAN or if this cable supports CAN

I have read through loads of brake posts on here so I know I need a pressure bleeder,, if I'm gonna have to change the master cylinder

Both the calipers moved back freely when I changed the pads but now the NSF caliper doesn't want to move backwards at all hence the binding

Hope you guys can help

Paul

Edited 17 May, 2010 by cab262

[KenONeill]

1) Quite possibly I'm afraid.

2) I don't have the relevant Haynes here, but Haynes says it's possible, so probably. One word of caution though if you want to do this, observe absolute cleanliness. Clean the outside of the cylinder ASAP, clean your hands and tools before starting dismantling, and work on a clean surface inside.

3) I think you're still stuck there if the cable's one thing and the car's the other. A 2004 car should be CANBUS though.

[cab262]

Thanks for the reply Ken,, The funny thing is that the brake pedal is hard with the engine off or on ?? And all the other posts that I've read suggest that when the master cylinder is Knackerd the pedal goes straight to the floor when they start the engine ??

[richm]

2004 Octavia will be ISO9141 (K-line) diagnostic, not CAN.

Mk2 2005-on cars are CAN

[KenONeill]

If the brake pedal is "always hard", I'm inclined to suspect the servo, rather than the master cylinder.

Borrow a car (pretty much anything except a Hydropneumatic Citroen) and do this:-

1) With the engine off, pump the brake pedal until it goes hard.

2) Leave your foot on the pedal and start the engine. You will feel the brake pedal get softer, and your foot sinking.

If that's not happening with your Octy, that strongly suggests a fault with the servo, or with the vacumn pump (if fitted).

[cab262]

If the brake pedal is "always hard", I'm inclined to suspect the servo, rather than the master cylinder.

Borrow a car (pretty much anything except a Hydropneumatic Citroen) and do this:-

1) With the engine off, pump the brake pedal until it goes hard.

2) Leave your foot on the pedal and start the engine. You will feel the brake pedal get softer, and your foot sinking.

If that's not happening with your Octy, that strongly suggests a fault with the servo, or with the vacumn pump (if fitted).

Thanks for the input guys,, But I have solved it "Hooray",, it turned out to be the master cylinder that I must have damaged whilst trying to bleed to conventional way,, even though I had what felt like a normal pedal IE hard when engine off & softer when started.

For some reason as the brakes got hotter the pedal lost that soft servo feel and became really hard and the brakes started to bind,, but if you hooked your foot under the pedal and pulled upwards the brakes would free off and the soft feel of the pedal returned. Also RICHM was correct it was K-Line and my old cheapy lead worked fine

Thanks Again Paul

[Wobsta]

Just top add another pretty much identical situation. Garage bled the system incorrectly, and the brakes were binding. Fixed with new MC.

 

Can be read about here:

 

http://www.briskoda.net/forums/topic/364777-adventures-with-brakes-or-why-i-hate-garages/

[kidology]

Best way to bleed octavia brakes is with engine running, you get a brilliant firm predal and no issues even doing brembos.

[sesachc]

I changed the back axle on the missus Tdi auto mk1, had rear wheel cylinder that was leaking and to be honest the brakes were ****, so changed the axle over to a disc, prefer the disc option for alot of reasons, anyways after the change bled all the brakes without the engine running and got a pedal, so thought all was well, so took the car for a drive for it to be 3 miles down the cars brakes are binding on, re-bled it all got a firm pedal ect.. was head stomp'd as to why they were binding on, so got new discs and pads, new rear caliper, changed the bearings, still nothing, so tomorrow i'll be doing the MC as this was the last thing that was on my agenda to do as everything else physical on the brakes work, just when it seem to "heat up" on a short journey it would act like this, so hears hoping so i can love the car again

[SuperbTWM]

Just top add another pretty much identical situation. Garage bled the system incorrectly, and the brakes were binding. Fixed with new MC.

 

Can be read about here:

 

http://www.briskoda.net/forums/topic/364777-adventures-with-brakes-or-why-i-hate-garages/

 

When bleeding the bakes using the pedal my Dad has always told me not to push the pedal all the way down to the bottom, just to half way or maybe a touch more to avoid damaging the seals.

 

I wonder if this is what has happened in these cases