What's the best method of replacing brake/clutch fluid?

[kangaroo 0]

I'm going to replace the fluid in my brake system this weekend. Looking at the service schedule it was last done 3 years ago (17k miles) so I figure its probably due a replacement. I would also like to do the clutch system while I'm at it. I have a few questions before I give it a go though:

 

1. Whats the definitive method/sequence for replacing the fluid. I read some things about pumping the pedal 20 times, leaving the ignition on for ABS, doing shorter brake-lines first, but I lost track.. Whats the best order? And how about the clutch system?

 

2. How much Dot 4 fluid will I need if I want to make sure I've replaced everything in the system?

 

Cheers for any advice!

[Henny 0]

I do it in this order: (no particular reason, just the way I've always done it... :| )

 

Bleed out the front (either side) until no more fuid comes out (ie you've emptied the reservoir)

 

Bleed out the clutch slave (same again) - you'll need 2 people for this one as the clutch won't bleed on a self bleeder kit for some odd reason... :roll:

 

With ignition on and topping up reservoir as needed:

Fill reservoir and bleed clutch until no more air

Bleed fronts

Bleed rears

Re-bleed fronts

Bleed master cylinder

 

if you're gonna change it all, go for DOT5.1 fluid... 1 litre should do you with some left over for spare... 8)

[dinkus 10]

You got any pics of that Henny? It would be good to add to the how-to site (http://the-corrado.net/.archive/forum/viewtopic.php?t=12416) Either that, or could kangarooboy take some pics when you do it?

 

Thanks guys, as ever keep up the good work :)

[kangaroo 0]

Hmm.. I was just reading through my dad's Mk3 Golf Haynes manual (closest thing I've got to a 'rado manual) and it said you cannot bleed the clutch system without pressurising it with a bleeder kit. Is this correct? Or can I just push/pull the clutch pedal to pump the fluid out?

 

Cheers for the advice Henny :) So basically I need to get all of the old fluid out, (until I'm pumping through just air?) and then refill it with some new fluid? Can I just pour the new fluid into the resevoir ontop of the old stuff as I go along, and replace it that way? Or does that not work as well?

 

I'll take some pics as I go along dinkus 8) Did you get my guide to replacing the gearbox oil btw?

[dinkus 10]

I'll take some pics as I go along dinkus 8) Did you get my guide to replacing the gearbox oil btw?

 

Nice one, the more the merrier, if you can take a note of what tools you need as well that would be very useful :D

 

I didn't get anything from you about gearbox oil, but I guess it's all in http://the-corrado.net/.archive/forum/viewtopic.php?t=12372 ? If so I'll add it up at some point.

[Henny 0]

Hmm.. I was just reading through my dad's Mk3 Golf Haynes manual (closest thing I've got to a 'rado manual) and it said you cannot bleed the clutch system without pressurising it with a bleeder kit. Is this correct? Or can I just push/pull the clutch pedal to pump the fluid out?

 

I've recently bled mine with no problems with nothing but a mate pushing/pulling the pedal, a jam jar and an 11mm brake spanner... ;) :lol:

 

You only need to get all of the fluid out if you're doing a full change... I've just found it easier to pump all the fluid out of one place and then you KNOW you've got air in the system from the reservoir onwards, so when the air has all cleared you're definately on new fluid.... ;) 8) The problem with re-filling as you go around is you never know where's got new fluid and where's still got old fluid in the system

 

Tools list is simple:

 

11mm brake spanner (has all but one side on it - 5 in total) to ensure you don't strip the head on any brake nipples ;)

Jam jar (to catch waste fluid)

Thin clear hose with rubber hose ends to put over the nipples (so you can see the bubbles/lack of 'em)

Mate to pull and push clutch pedal and push/release brake pedal...

 

8)

[Storm 0]

What are you supposed to do with waste fluid? :?:

[h100vw 0]

I stick mine in the waste oil thingy at the local dump. :roll:

[dinkus 10]

I stick mine in the waste oil thingy at the local dump. :roll:

 

Yeah make sure you dispose of it properly, don't just chuck it in the bin/down the drain.

[kangaroo 0]

Cheers Henny. I think I got everything apart from the brake spanner, but I'm sure I can find that down the local Halfords. I'll see if I can get round to doing it this weekend.

 

Dinkus, I sent you a pm about the gearbox oil guide several days ago, but I guess it must have got lost in the system or something. No worries though, you got the right thread, there's a word doc. file at the end of it with the guide inside. The how-to site is looking good so far :)

[dinkus 10]

Dinkus, I sent you a pm about the gearbox oil guide several days ago, but I guess it must have got lost in the system or something. No worries though, you got the right thread, there's a word doc. file at the end of it with the guide inside. The how-to site is looking good so far :)

 

No worries, I might have a crack at putting it up today... I think it's gonna be another slow day at work otherwise.

[Henny 0]

yup, my brake spanners are all from Halfords as their new PRO tools range is excellent.. 8)

[dinkus 10]

yup, my brake spanners are all from Halfords as their new PRO tools range is excellent.. 8)

 

And as I found out when doing my top mounts... if you break anything from their Pro range, you just take it back and they give you a new one, no questions asked! 8)

[kangaroo 0]

Was having a quick peeky round the car in preperation for doing the fluid change... I found the clutch slave and its bleed valve no probs, but I'm a bit confused over the master cylinder :?

Where exactly is the clutch master cylinder, and does it have a bleed valve? The one directly below the reservoir is the brake master, yes? Do I need to bleed both?

Also, does the ABS have a pump or something that needs bleeding?

 

Cheers!

[Henny 0]

Good questions, kangarooboy 8)

 

The reason you keep the ignition on is that the ABS will self pressurise and effectively bleed itself... 8)

 

You don't need to bleed the clutch master cylinder seperately, it bleeds through the slave cylinder... 8)

 

The brake master cylinder is on the servo (big round metal thing) and is indeed the one with the reservoir on top of it... Mine's got a bleed nipple there, so I bled it last as it's the highest point in the system so the air will rise to it as you go along... If you've got one, bleed it, if not, then it probably hasn't got one for a good reason... ;) 8)

[kangaroo 0]

eugh... well I made a start today, and came across several problems... firstly both my rear wheels were seized onto the hubs :( but i managed to free them. Then I found one of the bleed valves was blocked :roll: I managed to poke it around with a bit of wire and clear it out though.

 

Anyway, so far I've bled through a litre or more of fluid, and no air is coming out of any of the brake lines, but my pedal still goes straight to the floor!! Perhaps there's air still stuck in the system somewhere? Or am I doing something wrong? :?:

 

Also, what is this piece of machinery (attached image). It looks like it has something to do with the brakes, or at least the tubes coming out of it look like brake lines...?

[dazzyvr6 0]

thats the abs unit

[Henny 0]

Yup, that's the ABS unit... Did you have the ignition switched on when you bled the brakes? You need to with ABS else you'll never get alll the air out... :|

 

Also, there is a bleed nipple on the brake master cylinder on my car... if there's one on yours, bleed this and see what difference it makes to your brakes... 8)

[kangaroo 0]

Agh! This is driving me insane!! :brickwall:

 

I've bled all the lines again, and the master cylinder, till no air came out for a good 10-12 presses of the pedal (with ignition on too). Then out of desperation I decided to bleed the two valves on-top of the ABS unit. To my surprise quite a bit of air came out. So I continued until it stopped.

 

But I've still got the same problem... The pedal feels rock solid until I start the engine (when obviously the servo kicks in), then it just squishes right down to the floor! :cry:

 

(BTW: Can I reuse the new brake fluid, even if its gone through the system once? Its just I've already used 2 litres and its starting to get expensive...)

[kangaroo 0]

Okay, just to update the story of my brake bleeding nightmare:

 

After some big-style bleeding of all valves in the system I got the car to a state where it was drivable. I've since spent the last two days periodically bleeding, each time extracting a little bit more air. So far the brakes are back to normal, and with a bit more bleeding I think I can get them feeling even better.

 

I think the problem was that I bled the system dry right at the beginning. This introduced air pockets round the various lines and components, and getting rid of these has been the cause of all my woes. In the future, if I were to do a "refresh" of the current fluid I'd extract as much of the current stuff from the reservior and then simply bleed through all the old fluid, pouring the new fluid in as I go along. Its not perfect, and would require you to bleed through a substantial amount to make sure you've got new fluid in the system, but it would reduce the chances of getting air pockets. Or so I reckon...

 

On the plus side my clutch feels a tad better :)