changing brake fluid and bleeding complete system with ABS

[jedi-knight83 0]

Right...im not after a discussion on types of brakes and brake fluid etc as it has been done a million times before and i know the bits i want...

 

BUT...i havent been able to find a decent explanation on how to change the fluid in the complete system and then bleed it all successfully so i wondered if i could have some help.

 

I want to drain the complete system of all the old fluid and replace with new stuff with a different dot rating so i guess i need to make sure that all the old stuff is definately out before filling with new as i guess its not a good idea to mix.

 

So....

 

How do i drain the system of all old fluid?

How to i fill the system with new fluid (just poor into the reservoir under the bonnet??)

How do i bleed the system in the right order (remembering i have ABS)

 

thank you :)

[Kevin Bacon 5]

You'll hear all sorts of stories about dirt getting into the ABS pump, having to press the brake pedal 170 times with the ignition on if you get air in the system and so on and so forth.....

 

Vince flushed my fluid out last year and he just used an airline bleed system and blasted a litre of new fluid through all the calipers.

 

It's pretty straight forward to be honest....

[jedi-knight83 0]

so you didnt bleed it dry first? just bled each caliper one at a time and kept topping up the reservoir with new fluid? how do you know when new fluid is coming through the caliper? is it a different colour?

 

oh and was the ignition / engine on?

 

ta

[Kevin Bacon 5]

Yep just bled through each caliper until the fluid coming out was a different colour. Can't remember if the ignition was on or not as it was on the ramp when they did it.

[jedi-knight83 0]

ok thanks...sounds easy enough and much easier then faffing arounf with bleeding abs pumps and such like..

 

would it matter if im chaging the callipers?? obviously the new ones will be empty so its just a case of bleeding all the air out isnt it?

[Henny 0]

The ingnition needs to be on if you have ABS else the pump won't bleed properly...

[dinkus 10]

Can you take some piccies for the how-to site please?

 

Your ones from the serpentine belt change were very useful (I'm gonna put them up this week, promise!)

[jedi-knight83 0]

sure thing dinkus, im just finalising the purchase of my 288 setup and when i get the parts i'll give it all a go and yes i'll do a simlar write up to last time.

 

thanks Henny, just ignition or engine running? will i need to do the clutch aswell if im changing the fluid?

[Henny 0]

just ignition so that the ABS light has flashed on and then gone out again... :)

 

Yeah, bleed the clutch as well... it won't hurt and I'd hazard a bet that it's not been changed before... :|

[jedi-knight83 0]

ok, where is the bleed nipple for that please?

 

do the same...pump clutch untill new fluid flows through?

[markmcie 0]

Get the E-Z bleed kit from Halfords or the likes. Is dead handy for bleeding the entire system cause it works off the pressure in your spare tyre and as you open each bleed nipple the pressure pump the new fluid through the system. It also saves you having to pump the pedal and you dont need another person. You know the old fluid is out when you start to see the fresh fluid coming out of the bleed niple. And a brake system holds 2 liters of fluid so once you have used 2 liters + of new stuff you know you more or less have all the old stuff out.

[Henny 0]

bleed nipple is on the slave cylinder on the top of the gearbox near the coiled pipe... 8)

 

It's exactly the same to bleed the clutch as the brakes, except that you need to lift the pedal by hand as well as push it down 'cos the self return spring isn't strong enough to do it for you... :roll:

 

Oh, and you will have problems if you try to use one of the one-way-valve style kits to do the clutch, you need 2 people, one opening and closing the nipple, one pressing/pulling the pedal...

 

Once you have nice fresh fluid coming out, it'll take a few pumps with the nipple closed tight before the pedal will start to behave as normal... don't worry, this is also normal! ;)

 

Final tip: DON'T forget to pump your brake and clutch pedal quite a bit before you start to try and move the car after bleeding the hydraulic system, else you'll find that the brakes won't be as good as you expect and the clutch biting point will have changed slightly too! ;) :lol:

[NormanCoal 0]

If you are going to be changing calipers and therfore the hoses, then use an ezibleed system to blow all the old fuild out - keep the reservoir empty and it wil push air into the system and bleed it all dry - you wont have any puddle on the floor then, and when you push new fluid through you will know that its all new

[jedi-knight83 0]

so this e-z bleed thing actually sucks the old fluid out?

[kangaroo 0]

If you are going to be changing calipers and therfore the hoses, then use an ezibleed system to blow all the old fuild out - keep the reservoir empty and it wil push air into the system and bleed it all dry - you wont have any puddle on the floor then, and when you push new fluid through you will know that its all new

 

I did this and introduced more airlocks into the system than i thought was imaginable. :roll: I then spent 3 days continually bleeding the system, getting a little more air out each time, till eventually it was all ok. I swore a lot during the period of time...

 

Maybe I just did it wrong or something.. (it wouldn't be the first time). But if you're doing a simple brake-fluid replacement then just top up the reserviour with new fluid as you go along, it'll make things a whole lot easier.

[dr_mat 0]

No, it blows it all out...

[jedi-knight83 0]

ok, thanks kangarooboy, im thinking that just topping up sounds easier and im sure that way will get most of the old fluid out anyway

 

i will be changing callipers at the same time though so i guess there will be alot more air to pump through before i see fluid but it souldnt be a problem

 

im not gonna touch the abs pump...just gonna leave ignition one throughout

 

still a bit unsure about the clutch...open nipple / close nipple etc...sounds a bit fiddley! may just leave that as i dont want to intorduce air by me cocking it up :roll:

[jedi-knight83 0]

No, it blows it all out...

 

back out into the reservoir where you can schringe it out?....i think i get it although dont like the sound of it

[Supercharged 2]

The ingnition needs to be on if you have ABS else the pump won't bleed properly...

 

Apparently you don't (I thought you did until recently) - I think this came from Bentley manual and only applys to US cars...

 

Just don't get any air into the system otherwise you have to go through a very indepth VAG COM procedure involving 4 people and depressing the brake pedal 170 times before ABS will work again!

[jedi-knight83 0]

so is it best to suck out all the old brake fluid from the reservoir and thenput new stuff in before doing any pumping and bleeding? that sounds logical to me anyway

 

Supercharged, i'll leave to ignition on to be on the safe side.....seeing as most ppl say to have it on and i doubt it will have an adverse effect even if it is on.

[NormanCoal 0]

The reason that I have said to push all the fluid out first is that you are changing calipers - when you do this you will end up with fluid all over the floor if you dont get it out first.

The ezibleed sytem - connect the air hose to a spare tyre, connect the cap to the top of the reservior (after removing the normal cap) and leave the bottle (normally you put new fluid in it) empty. As soon as the hose is connected to the tyre this will use the air in it to pressurise the system. Then crack open the bleed nipple on each caliper in turn to empty the fluid out.

 

I am about to put 288 calipers on my VR (once I have some wheels to fit over) and this is the procedure that I will use

[jedi-knight83 0]

im not fussed about fluid on the floor to be honest and wouldnt that cause air to be sucked into the abs pump?

[markmcie 0]

I was told not to let the master cylinder go dry cause you will end up with tons of air in the system and it will take forever to get it all out.

 

Its a messy job changing lines / calipers but just use an old biscut tin or something to catch the old fluid.

 

And dont put your hands near the body of the car for obvious reasons :shock:

[NormanCoal 0]

If fluid goes on the floor, then it will be replaced in the lines by air, no matter which way you look at it

[jedi-knight83 0]

feck...so it does...i guess the fluid will just drainout until eventually there is air in the abs pump :mad: