Spongy pedal after bleeding - abs, Cupra Sport

[Caffienated]

Ok, title pretty much says why I'm posting.

No leaks I can see. No bubbles in fluid leaving bleeds down tube.

Pressure bleeding method used, 15psi in the spare tyre.

I've replaced every hard line on the car and all the flexis too.

Any ideas welcomed... MoT required!

(shock return of the six million dollar beezer to the road!)

 

[M1KEH]

You need to use the bleeding mode in vag-com I believe. Even in a pressure bleed.
Not sure which one you need to use for the ibiza though.
http://www.ross-tech.com/vag-com/cars/absbleeding.html

 

[M1KEH]

Or bleed the brakes with the engine running apparently may help.

 

[Caffienated]

You need to use the bleeding mode in vag-com I believe. Even in a pressure bleed.
Not sure which one you need to use for the ibiza though.
http://www.ross-tech.com/vag-com/cars/absbleeding.html

WTF? I need a computer to bleed the brakes properly ?

Really? Off to check linky and have another go with the engine running...

 

[M1KEH]

WTF? I need a computer to bleed the brakes properly ?

Really? Off to check linky and have another go with the engine running...

It might be you don't need a computer for the mk2 it seems.

 

[Caffienated]

Okay, when he says 'also this doesn't take the place of good 'ol two man bleeding' does that mean that a two man bleed makes triggering the abs redundant?

 

[M1KEH]

Nope it just means that this method only bleeds the abs section of the pump.

 

[Caffienated]

Sorry... Typing while you posted

I can follow that getting the pump moving would be a good thing. Hm. Let's try withengine running once more...

 

[Caffienated]

Nope it just means that this method only bleeds the abs section of the pump.

A bleed nipple on the pump would have been nice!

Although if mines leaking - looks like it might be - I'm going to need to sort that first

 

[M1KEH]

Yeh leaking pump is not too good.... On another related note.....
http://www.houseofthud.com/cartech/abspump/ABSProcedure.html

 

[Caffienated]

Okay... So you aren't actually bleeding the brakes while cycling the pump. That would make life easier!

Basically, even if I replace the module- I was going to anyway for the leak I think- I'm going to need a VAGcom to complete?

From memory pretty much any old laptop with a serial port will do. What else do I need and where's good to get it?

Thanks for links...

 

[M1KEH]

I'd wait for flapper to give more info on this as he has done module swapping before.

 

[Caffienated]

K... Need this sorted pretty soon ... I've hogged the garage pretty much since Inters now on and off and my dad really wants it back!

Living in the same place as the car gave up would have been really good...

 

[Caffienated]

Had a bit read and see I can pick up a cable under a tenner and download vcds-lite free with limited functions, usd99 to get full functions in lite.

Can't see obviously if lite/ unregistered lite can do the abs cycle. Off to read some more (warmer than garage inside!)

If anyone knows which version I need and if I need a registered version I'd love to hear!

 

[Caffienated]

Just a thought - and I don't plan on trying this!!!!!

Would bleeding then an almighty skid to get the abs going then rebleeding do the same?

Like I say, it'd be a pretty insane way to try, but should it work in theory?

Pub time I think if I'm having ideas like that!

 

[Fl@pper]

Basically, even if I replace the module- I was going to anyway for the leak I think- I'm going to need a VAGcom to complete?

always medium pressure bled mine and always seem to have to over it twice to get it bang on wierdly

as for the module as said in other thread it's a straight swapover as long as you match the numbers on the ecu even if you split it and change just the solenoid block you'll be fine

all i did with mine was run vagcom standard error check after to make sure i had wiring back in properly (as it is upside and an arse to clip in) and cleared one sensor i'd unplugged and forgot about when trying to clear out the rear pipes

 

[Caffienated]

Cool, thanks!

So VAGcom is useful but not essential for this job. Number of times it would have been handy I think it's time...

Cheers for all the help and I'll let you all know in a couple of days how it's gone when I've got it sorted (hah!) Got to go home for a couple of days for work before Christmas...

Sorry this has spread over two threads... Started off thinking it was two separate problems. Probably actually is, but I'm clearly not going to get to the bottom of it while my abs unit is leaking!

(I think it's just sulking at having spent a month in a plastic bag on the garage floor while everything else was in bits...)

 

[Caffienated]

YAY!

Return of pedal pressure!

After many carp results with pressure kit, even with VAGcom to cycle the abs pump and bleeding with a running engine, concluded that only possible problems left were shot mc or leaky servo/vac plumbing or insufficient pressure applied on bleed.

Vac/servo problems ruled out by pedal behaviour, so I took advantage of the mighty right foot of my brother, who's also home for Christmas.

Several trips round the car later, he suggested moving to open/press-hold/lock/release bleeding, and we've finally cracked it. Mot booked for tomorrow lunch, so unless mr tester hates my rear discs which seem to look worse than when I took everything apart, I should have a nice new mot just in time to buy a new tax disc. Yay.

We've got through a shocking SIX litres of hydraulic fluid!!!!!

In case anyone else is interested btw, the Mk4 Golf ABS pump went straight on, but lit up the lights. VAGcom showed a fault indicating that the numbers were wrong. Actual part number was same, but used the 'recode' option to crib the shop code and manufacturer codes from knackered pump to good one, which worked really well, and was probably easier than splitting the unit...

 

[andycupra]

so using a non-pressure system, (ie old open/press/hold method worked..)
Interesting.

I was going to ask how much you had driven it, as many people have had a spongy pedal after bleeding for the pressure to slowely return fully with use.
Is it possible that one of the calipers, eg rear had been retracted too far?