I give up...can't bleed the brakes EDIT, now sorted

[PhatVR6 0]

This is doing my head in now....

 

was a 2.0 8v. I've kept the ABS, but now have 288's on the front and a wilwood brake bias valve in each rear brake line.

 

all the calipers are as I had on the car previously, as is the servo and M/C(which has been out when I changed the wiring loom).

 

I Just CANNOT get a decent pedal. as soon as I turn the engine on the pedal almost hits the floor.

 

I've bled the calipers 4 times, and the M/C. no bleed nipples on the ABS unit. I've even tried turning on the ign and engine as I press the pedal, to make the ABS pump click (to relaease any trapped air from the valves) but I still get no air coming out of the calipers, just pure fluid.

 

Ive tried it with an eezi-bleed and by pumping the pedal (but not all the way to the floor as I know that can damage the master cylinder).

 

An hour ago I have not a bad pedal feel. so Icleared all the tools up, went to take it out for a test drive, and nothing, pedal just hits the floor with next to no resistance. huh? it was fine a minute of 2 earlier.

 

WTF!?!? am I doing something wrong?

 

I've noticed the white plasic bit on the servo has some scuffs on it, so I'm not sure if it's sealing properly (probably knacked it trying to wrestle the thing through the bulkhead, nightmare job). It does make an "air" noise as I press the pedal.

 

I'm just totally at the end of my tether, and out of ideas as to what is wrong with my brakes and why they won't work at all now. I can get my missus to pres son the brakes and I can still push the car with one hand....they are dead.

 

Help!!!

[VR6 0]

Ignition on whilst bleeding?

 

Edit: Think you said that .....

[PhatVR6 0]

yep, tried it with ign on, and off, and even with engine running.

[24V Renshaw 0]

I am going to be doing mine in the next day or so. I was told by the VAG technician that with the MK4 ABS system you have to go into VAG-COM, set the brake system to "basic settings" and that opens all the valves up in the ABS unit. Not sure if you can do that on the Corrado stuff but might be the same?

 

Jay

[Joe M 0]

Have you tried starting the engine with the abs disabled? I know the pedal on mine is fairly soft (though not as bad as yours sounds) but if I disconnect an abs sensor its solid.

[RW1 0]

Sequence etc is here, nothing special.

 

Servo pipe wouldn't affect pedal. If anything if leaking, pedal would be harder to push due to leaked vacuum. I think "pedal hits the floor with engine running" suggests the servo working and giving pedal assist.

 

http://the-corrado.net/.archive/forum/viewtopic. ... highlight=

 

Q's

1. Damage component like u say.

2. Master cylinder gone in some way on both circuits.

3. Fluid is DOT 4 and not silicon DoT5

[PhatVR6 0]

fluid is definitely dot 4

 

I'm still thinking it's the ABS with air in it, but I feel the M/C may have died after all the fartng about as it's just totally dead now, zero pedal feel, just hits the carpet (well...it would if I had any carpets in..)

[PhatVR6 0]

the system is too old for vag-com to operate the valves, it just says "not available"

[24V Renshaw 0]

Must be the MC then mate. I had the same thing once with the G60 set-up. Bled three of the calipers fine, then all of a sudden nothing. Exactly the same as you have. Ended up having to buy a new MC, then all was mint.

 

Jay

[PhatVR6 0]

nightmare, I have no money to buy one, and no time to wait for one either............

 

I have a late golf vr6 one, but the fittings are a different size....

 

I'm screwed.........anyone want to buy a cheap unfinished project? I'v had enough... :-(

[24V Renshaw 0]

These things come to try us mate. Stick something on Ebay to make the £60 for a new MC.

 

Jay

[PhatVR6 0]

haven't got time. I need the car on the road for sunday. I already missed croft and gti fest, I'm not missing inters as well.

[Dub Style 0]

I had a rite nightmare with my vr brakes when i changed the rear calipers to mk4 ones.........i dont know if the abs pump on the vr's or 8v's differ but mine did have bleed nipples on the top of the pump......i also bled the clutch which helped a bit.

[Scruffythefirst 0]

Are all the connections tight and not weeping?

[gibber 0]

I got the M/C that I just took of the US G60, yours if you want it mate!

[dr_mat 0]

Yes, I believe there's bleed nipples on the ABS pump. I'm sure I read that somewhere....

[PhatVR6 0]

well, definitely no nipples on the pump.

 

I cracked off the lines coming out of the pump, one of the rear ones let out a sh1t load of air, and I managed to then get a load more out of the correspoinding rear caliper, which has firmed up the pedal alot (but it's still crap).

 

getting some new front ABS sensors today to get that ABs light to go out, then I need to take it out and get those discs cleaned up.

[24V Renshaw 0]

Paul,

 

I hear you managed to get the brakes working, what did you have to do in the end?

 

Jay

[PhatVR6 0]

well, I think it was a combination of a few things. firstly, that air in the pump. cracking off the unions definitely let a lot of air out. but I think this has also been a problem:-

 

I have no brake discs securing screw in one of my hubs (the old one is snapped in and I haven't got round to drilling it out yet). so, when you take the wheels off. if you knock the disc it falls off the hub slightly. the knock on effect of this being that it pushes the piston back int he caliper. so when you press the pedal, it's got to take up that slack again before you get a bite........when I bled the brakes with the wheels on it sorted it.

 

I've got 2 new A?BS sensors in the front now though, so as soon as I change the connectors on the back sensors 9the syncro ones were different) I'll get that ABS light out foe good and try the old "lock it up on some gravel" trick to get the pump kicking in, then I'll bleed it all again.

[24V Renshaw 0]

mmmmm? Sounds exactly the same as what mine will need. The MK4 pump seems very sensitive to air locks, I will try cracking each of the unions when I get back from Worthersee. I can get the pump running via VAG-COM but it sounds weird, which again suggests airlocks to me.

 

Congrats mate, bet your well chuffed its on the road.

 

Did you manage to fit the engine under the bonnet with the engine cover on?

 

Jay