Spongey pedal after SS lines and fluid flush

[Sp3no82]

I have just changed my brake fluid and swapped to SS lines due to the feel of my brake pedal being so poor. Imagine my horror when after all this work it's now worse than ever!
I ran the ABS test function numerous times with my VCDS, I pressure bled the system numerous times whilst tapping the calipers and lines to remove bubbles and I'm not getting a single bit of air out of any of the lines.
I'm completely stumped, with engine off the brake pedal will pump up hard then start the engine and its goes soft so master cylinder seems ok. Where do I go from here, will bleeding the clutch help at all?

 

[csaby1973]

Hi,was the old break oil dirty?maybe clean up master cilyder pump will help.

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[Daniel M]

I had something similar after changing rear lines an a rear caliper albeit on my previous car (Leon). I bled the system numerous times and was adamant there was no air in the system.

I bled it again an it was perfect. Chances are there is still air in the system.


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[Sp3no82]

Will bleeding the Clutch help at all? I had all of the calipers off the car and all the lines for over a week so the system was very empty and allot of air would have got in. Is there anyway to bleed the master cylinder as the reservoir would have run dry whilst it was sat there.
The fluid that came out originally was clean to be fair, I keep reading to not reuse the fluid that comes out but I have put 2litres through it now and only clean fluid is in the system, I am toying with the idea of running a hose from a bleed nipple back into the reservoir and just keep pumping over and over and circulating it thorough to pick up any trapped bubbles

 

[Jon13s]

Just been through similar myself. Bleed, bleed and bleed again. Albeit there has been a gap of two months since the last time we tried. It has now come good.

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[Charlie Farley]

Have you tried just letting gravity do it's work.
Stick a piece of hose on a bleed valve , loosen it off just enough for oil to seep out then put it into a container, leave for a few hours or overnight .
I have used the same method numerous times on our e-type, which is a real pain to bleed the air out, its spongy pedal otherwise.
I normally just have the bleed valve open a small amount , gravity does it's thing and helps oil move downwards and air is expelled, you may need to do it on the furthest caliper first and work back from that point.

 

[Baka]

Might also be worth borrowing a pressure bleeder (or finding a garage with one) if you're doing it manually. They can push out airlocks & bubbles you'll struggle to shift pumping the pedal.

 

[Charlie Farley]

I used a gunsons easy bleed on my old bus when I upgraded to 18z's with ss lines, don't recal having any issues, maybe a bit more pedal travel for a day or so but not spongy .

 

[Sp3no82]

I use a gunson pressure bleeder that works off a spare tyre. I have booked a day off Wednesday to give me a complete day of bleeding the brakes. Oh joy it's like my least favourite job! Had a look at the master cylinder and there does not seem to be a way to bleed these so will do the clutch and run the ABS again with VCDS. I did notice in the Haynes manual that the bleed sequence is different to what I have been doing. Haynes says do both fronts first then the rears I have been doing it using the furthest from MC method

 

[Sp3no82]

Update on this, spent 6 hours bleeding the clutch, bleeding the calipers over and over, did this whilst running the ABS pump using VCDS, I tried pumping the pedal at the same time as using the pressure bleeder which had resulted in basically the same soft pedal I had before I started the whole job. The car stops fine it just has a spongy feel to the pedal that was there before all of this work was completed, at one point I had the ABS, ESP and low brake pad warnings lighting up the dash that wouldn't go away but finally all gone and I have brakes just very disappointed with the final outcome.

 

[Baka]

It can be a symptom of a failing master cylinder, might be worth looking into? Especially if the fault was present before all your hard work, and is still present now?