Having a mare

[Wull]

Brake bleeding issue

I replaced the o/s/r brake caliper on my A3 1.8 sport and the system was open for a short while.

After bleeding said caliper to the point in which there's no air coming from that caliper,just clear brake fluid and yet the brakes are pretty much non existent.

I bled the n/s/r caliper and tbh there was no air from that one at all,I then moved round to the n/s/f caliper to find that the bleed screw is rounded off and its left me in a bit of a predicament

now the car is at work which is 15 miles from my friends garage and tbh I'd prefer to solve this myself.....

any ideas?

 

[Greg-S3]

Bleed it via the brake hose dude, that'll work

 

[jojo]

Did the brake fluid reservoir drop below 'min'? If so, then you need to bleed the master cylinder which sits directly below the reservoir.

 

[S3Hendry]

Did the brake fluid reservoir drop below 'min'? If so, then you need to bleed the master cylinder which sits directly below the reservoir.

Is there a bleed nipple on the master cylinder jojo?

 

[epox]

There are 2 on the mc iirc, pain to get to.

 

[Wull]

I don't think the fluid dropped below the minimum as I've been topping it up as I went.

I could see at least one bleed screw on the m/c and even that one looked like a right pain to get to,so if there's another one it must be even more awkward.

 

[VAG-Slag]

Is the pedal soft and going to the floor or do the brakes just feel week?

 

[Wull]

Is the pedal soft and going to the floor or do the brakes just feel week?

Soft and going all the way down.

 

[jojo]

There are 2 on the mc iirc, pain to get to.

It's only difficult to get to if you own an S3, as the charge pipe is in the way. He has an A3.

 

[JimS3]

Usually gravity bleeding the master cylinder is adequate and makes things easier, just crack the nipple and let the fluid flow out for a short while.

The rear calipers can be a pain to get all the air out, try giving them a few taps with a mallet to dislodge the air and re-bleed. Sometimes this needs doing a couple of times.

 

[A3_130]

Had exactly the same thing happen with my 8l recently except it was the o/s/f where the bleed screw rounded off. I bought a replacement caliper in the end as the whole thing had seen better days and I couldn't easily drill out the heavily corroded bleed screw. I ended up having to bleed the master cylinder as fluid got too low, it has two bleed nipples that need a 7mm spanner. Bit of a fiddle to get to but easy enough. I got fed up bleeding the brakes with the 2 man method as it wasn't doing a great job so I invested in a Gunsons eezibleed in the end which I found really good.

 

[A3_130]

Might be worth buying some bleed screws to replace the others if they're looking a bit corroded - after the hassle I had with mine I replaced all the caliper bleed screws for new ones.

 

[Wull]

Cheers for the replies

I'll give bleeding the m/c a go and I'll try bleeding the front left caliper by cracking open the banjo bolt......it works a treat on the m/c on the motorbike so I'll try that.

 

[daz-20vt]

How did you bleed them? Pressure bleeder or pumping the brake?
Sometimes pumping the brake when bleeding can damage the seals in the master cylinder which will also give you no pedal.

 

[Wull]

How did you bleed them? Pressure bleeder or pumping the brake?
Sometimes pumping the brake when bleeding can damage the seals in the master cylinder which will also give you no pedal.

Two man method.

 

[daz-20vt]

Can anyone else confirm this is or isnt the correct method for these brakes?

 

[Wull]

Can anyone else confirm this is or isnt the correct method for these brakes?

The manual states a few methods and this is one of them,I can't really see why it wouldn't suffice,other methods may be easier but the two man method should work.....not on this occasion though as per usual

 

[daz-20vt]

Google flipped seals master cylinder to see what im on about. I know at least some of the 8l cars suffer as ive had it on my s3.
My mechanic did it 2 man method and flipped the seals. Pedal travel was a joke!! Replaced the seals on the master cylinder and got the pedal back.
Not trying to scare just fyi

 

[jojo]

VAG cars prefer the pressure bleeder method, 2 man works, but like you say, can flip the seals.

 

[Wull]

Oh dear,I hope that's not the case

Is there anyway of knowing if that's happened?

 

[daz-20vt]

Bleed the whole system inc the master cylinder.
some people run an abs check on vagcom when they bleed brakes to so that wouldnt hurt.
If still no joy id be considering looking more into the MC seals.
So many methods and theory's on this. Some people say its an online myth.
If you do the 2 man method pump slowly and dont pump to the floor is what i have read?!

 

[Wull]

That's them working now.

After work and a game of golf I bled at the m/c and that done the trick,working spot on now.

Thanks everyone!!