Air in Mk2 Galaxy tdi Brake system that wont go

[t_aslam]

Hi guys,
I have a 2005 tdi galaxy with 235k on the clock. Last week I made a slight error with bleeding the clutch. Ever since the clutch was changed I have had air in the system resulting in a sticking pedal are partially operative pedal. I purchased an eezibleed kit and hooked it up. There is a clear pickup hose inside the pressurised bottle which attaches to the output side (new fluid pushes through this). I accidently attached it to the input. Fast fizzing Air bubbles emerged through the output and was pushed through the system. So much air pressure has built up that when I disconnected the valve from the pressure source (the tyre) fluid came out of the air hose!!! The reservoir ran dry and hey bingo brakes went totally shit. New brakes all round and 1000 miles on and brakes are still crap. Very spongy and probably half the braking force as before.
I have bled it the conventional way with someone pressing the pedal and me catching the fluid at the bleeder all round and ensuring the fluid never ran lower than max. No luck.
Also when your braking at a very slow speed the brakes have an 'on' and 'off' effect as if the brakes are grabbing then letting go, then grabbing and so on... kind of gently jerking you to a stop.
Any help is greatly appreciated.

[Mirez]

Oops!  It's possible to get air-locks within the ABS system if it runs totally dry, you can use VCDS to activate the pump and purge the system - after that you may be looking at mechanical damage to the brake master cylinder

[t_aslam]

 Thanks Mirez.  I applied an emergency stop earlier and got the car to skid. Whilst it has improved the pedal pressure and on and off brake effect it still isn't 100%. Apparently this technique helps by activating the abs unit hence pushing air out into the lines. So maybe another bleed is in order.
But before I do that I have VCDS lite. Will I be able to perform an abs flush with the lite version? Thanks.

[Mirez]

Not sure tbh, can you access the "Output Tests" section? That's the easiest way of doing it, else you'll need the "Basic Settings" section

[t_aslam]

Ok I've bled the abs system and the pedal is a lot firmer. BUT, I have another problem. The steering and in fact the whole car shakes when braking from high speed. Sometimes it is accompanied by a knocking sound from the front right. This only happens when braking and I cannot figure out what it is. The wishbone bushes look fine, the track rod ends were replaced about 60k ago with genuine parts. They don't appear to have any play and neither do the lower ball joints. I also replaced the caliper guide pins and greased them before fitting.
Could it be that the air in the system caused my new discs to warp all round? That's the only thing I can think of.

[Mirez]

Eeek that's not sounding good. I can't see how air in the system could warp a disc, it would need to get seriously hot for that to happen.
I would double check the caliper guide pins are torqued up correctly, as are the wheel bolts. You didn't overdo the grease did you?

[t_aslam]

Hi Mirez,
Nope in fact I only regressed and used new pins yesterday. I've been told on another forum that it could be inner tie rods. It's going in for an MOT tomorrow morning so I guess something should come out of that.

[Chrispb]

Did you change your discs to cure the vibration problem, or has this started since you changed them.
What's the condition of the rear discs?

[Mirez]

Also, where did you source the discs from?

[t_aslam]

Oh yeah brand new pads and discs on front and pads only in rear. After the problem began I decided to change the rear discs too but to no avail. I always use pagid pads and discs from euro car parts as I do a lot of miles and they've always been fantastic. Used em
On the wife's A class too without issues.
Just to clarify, the problem began after changing the brake change and not immediately. Now I definitely had air in the system because of another problem and that has now been sorted. So while the pedal is a lot firmer and bites from the top this shaking problem hasn't improved.

[Chrispb]

If that was mine I would remove the disc's just to make sue there's no debris trapped between the disc and hub, if that's OK I would check the run out on the disc's and hub's by using a dti gauge (dial test indicator)

[t_aslam]

An update,
I've replaced the front discs and have not had much of a chance to drive around and let them mate with the pads properly. Will test for a week and report back.

[t_aslam]

Ok, new discs are worn in, new lemforder wishbones, new outer driveshafts from J&R and TRW drop links. No more shaking when braking but now I sometimes get a tremble from the care around 15-20 mph mostly when turning.
Maybe the wheels are out of alignment??

[plumbc007]

u probably have possibly flipped the seals in the master cylinder check and replace as necessary 

[t_aslam]

I don't think I have as the car brakes fine now. It's just this tremble when driving and turning at the aforementioned speed.

[Mirez]

You should always get the car aligned after fiddling with the front suspension anyway...

Did you change the lower ball joint?
Did you change the track rod ends?

Both could cause a wobble, both are prone to wearing and both will be under more stress now you've changed the arms