Brake bleeding questions

[Goldie 2]

Right, ive just refitted my rear beam and have Mk4 rears, new rear brake lines and flexis and have attempted to bleed the brakes and am a bit stuck..

 

This is where im at:

 

Ive been round each wheel, back - front, ABS Block and Master Cylinder and done the correct procedure as per when i fitted the 288s but they are still uber spongy.

 

Im starting to think that the reservoir was empty before i started and have read that this needs extra stuff doing to sort. Talking to a mate today he said do the master cylinder first and then go round each one as per normal..

 

Anyone have any ideas on what the best plan is??

[Supercharged 2]

With the MK4's you need to now press the brake pedal a good few times with the handbrake cables unhooked, then bleed (with car on ground / bias valve open) then connect handbrake cables...

 

They will still probably feel a bit vague until the pads have beeded in but should get better after a couple of hundred miles...

[dinkus 10]

Not sure if it's much help, but worth noting the difference.

 

If you've got new pads then they'll be shite for the first few miles - the pedal should feel solid, but they just won't bite.

 

If you've got air in the system still, then the pedal will be spongey and it won't bite :(

 

The best way is to make sure you never drain the resevoir, then you're not sucking any air into the system from that end of things. Not much use to you now, but you know for next time :lol:

I

I'd do with starting at the master cylinder and working your way around again though. If needs be, you can just keep going around until it's all bled. FYI - you should get about 12 full pumps before you drain the resevoir. Ooh err :lol:

[Goldie 2]

Appreciate the reply peeps..

 

What do you mean by Bias Vv??

 

I did do it with the handbrake cables attached so ill try again with them off and go round a lot of times till im sorted..

[dinkus 10]

There's a bias valve that controls the front/rear brake balance attached to the rear axle on the passenger side. Can't remember how exactly, but you need to wedge it open so fluid can move freely front-to-back. It'll flow without wedging it open, but not quite as freely as when you wedge it open.

[Goldie 2]

Ah, the compensator?? Anyone ideas of how to wedge it open??

 

Kepp it coming Dom, all handy info..

[dinkus 10]

Aye, that's the jobber.

 

No idea how to wedge it open though, cos when we did mine the other week, we didn't bother :lol:

[Goldie 2]

Ah, that makes it sound optional, might just sack that bit off then..

 

Right, im off to take the wheels off (AGAIN), unhook the handbrake and do it all again...

 

I may be some time... :)

[zak 0]

i would definately wedge the bias valve open, it has a tendancy to trap air unless you do. its on the near side attached to the rear beam

[KADVR6 0]

i have done the "easy" brake bleeding twice, its a s***e job i have never been able to get it done properly. the last time i just bled them so i could just about stop, and then got the nearest VW garage to bleed them properly. it only cost me £25 and the brakes were perfect afterwards. much less hassle than doing them yourself.

[Goldie 2]

Well i went out and had another go and suprise suprise its no different, did get air out at all corners but pedal just feels the same..

 

I cant think of anywhere who i could take it to to get it sorted tomorrow as id really like this sorted. Also failed to get the exhaust put on today as the guy who i was going to ask is on holiday. On the plus side i paid 100 quid for a round piece of paper that in 6 months is worthless, not a happy camper....

[Toad 0]

Dinkles went well TBH, think it was the fact that we never emptied the resevoir that helped us. You can put a wieght on the brake pedal so that it's held slightly down and that stops the fluid escaping.

 

You can cable tie the bias valve open, theres a helpful pair of rings on it.

 

did you bleed the master cylinder and ABS pump again when you'd finished?

 

Also ignition on or off?? I prefer to leave it off. Try pushing down hard on the pedal, then get someone to open the nipple, and repeat. CorradoVR6_Nos gave some good tips in another thread.

[bruny 0]

,

What a job :cuckoo: had four attempts starting at master cylinder, onto abs pump, front nearside, front offside. valve compressed rears bleed with and without engine running

having replaced brake lines,discs,pads and hoses. Struggled to get proper brakes. Have driven gently to bed things in they are now improving. :? Just seems to need a few miles to let things settle in

[Goldie 2]

I have bled the system today 3 times, compensator open, bit of ignition on and off, keep getting bits of air at some stages but overall im no further forward. The brakes do work but the pedal travel is large so its gotta be air.. I have done Master Cylinder before and after, tbh im stuck..

 

Anyone else got any suggestions??

[Toad 0]

You did both nipples on the ABS pump?

[Goldie 2]

I have indeed mate, the back one is a complete bar steward to get to with the AC relay bacnk sat on top of it..

[Toad 0]

the back one is a complete bar steward to get to with the AC relay bacnk sat on top of it..

 

:(

 

That's a bugger.

 

I might be around tomorrow if you want a hand?

[Goldie 2]

I may have a man to see in Waterlooville who may be able to help. If not though Tom i might call that in, ill let you kno how it goes, appreciated..

[StormchargedVR6 0]

you end with the master cylinder. Start with near side rear.

[Goldie 2]

Ive tried that and ive not had much progress..

[zak 0]

you could also try bleeding the caliper of the carriers, wedge a bit of wood so the pistin is held back. This can free some trapped air?

 

if not and you can get it good enough to drive safely then take it to a garage with a vacuum tool, this will suck the fluid from the bleed nipple

[Goldie 2]

Im hoping to do that tomorrow, it stops fine, its just the travel of the pedal. Fingers crossed i get some joy tomorrow..

[StormchargedVR6 0]

sorry mate, im talking do it with a airline bleeder. Your do it the old way.

 

wonder its taking time to get air out.

[Goldie 2]

sorry mate, im talking do it with a airline bleeder. Your do it the old way.

 

wonder its taking time to get air out.

 

The guy who may be helping tomorrow will be going in with an airline bleeder, ive only been using the old school way..

[StormchargedVR6 0]

it be fine then, do the clutch same time.