Brake fluid amount

Tomsk

Tomsk

Member
I am going to change the brake disc/pads and calipers on daughters Fsi. Just wondering how much brake fluid is in system as want to flush with new. Also going to bleed clutch. Just don’t know whether to buy 5ltr of brake fluid. Any ideas.
 
5lts will be more than enough, you'll have plenty left for top ups etc but remember to keep it sealed as its hydroscopic and attracts water if left open. Work out if its more expensive to buy separate 1ltr bottles (which should keep longer if the seals are not broken) or to buy a 5ltr and not worry about any left over if not used for any period of time.........of course you could use it all if you keep bleeding belt and braces style.........lol
 
Dot 4 only. Bleed the furthest brake from the reservoir working back to the nearest one, rear left, rear right, front left, front right then clutch cylinder. Do not press the pedal down further that in normal use, this can damage the seals in the master cylinder. Do not let the level get too low. If the ABS pump runs out of fluid you will need VCDS. I personally suck out most of the old fluid before I start using an old turkey baster, refill with new fluid then start the bleed process. After about 6 pedal presses I top up the fluid all the way to the top. You very probably already know this but be gentle with the bleed nipples spraying them with release fluid first and do not over tighten when finished. Usual safety precautions, secure car not just on the jack, don't get brake fluid on the paint, in your eyes or drink it and dispose of the used fluid correctly as required by your council. Best not to do it when it is raining, you could have to wait a while. When changing the calipers clamp off the flexi brake pipe to stop the fluid going everywhere.
As I said not telling you anything that you probably do not already know. More an aid to those that have perhaps never done this type of work.
 
Hi all, I'm planning to do the brake fluid change first time myself. I've done my research, the only question is, can you reach and loosen the brake cylinder valve, without removing the wheels one by one? I've only got 2 ramps and the drive way is a bit downhill, so lifting the car might not be good idea. Cheers
 
Put the rear of the car up on the ramps. Once secure and the car left in reverse gear you can reach the rear bleed nipples by going under the car and by turning the steering fully left reach the left front and fully right for the right bleed nipple. Clutch can be either done when rear on ramps or once car back on the ground. Spray some penetrant onto the nipples and use the correct spanner. Do not open the bleed nipples too far, try not to shear them off and do not over tighten when refitting them. Aim to get about 250ml out of each bleed nipple that way you will have flushed out the old fluid. KEEP THE RESERVOIR FULL OF FRESH FLUID AND KEEP REFILLING IT AS YOU BLEED. Try not to press the pedal down further you would normally when braking to prevent damage to the master cylinder seals. Vacuum or pressure bleeding is a better way to do it.
 
A related question from a non mechanic here, trying to understand more about my car.

From memory the A2 service book says brake fluid service every 24 months/20,000 miles.

My question please: what is a brake fluid service. Is it drain and refill, or just top-up?

Thank you, Andrew
 
A brake fluid service is a flush, refill and bleed of the DOT4 brake fluid. It should also contain a clutch flush and bleed but quite often this is not carried out.
 
audifan said:
Put the rear of the car up on the ramps. Once secure and the car left in reverse gear you can reach the rear bleed nipples by going under the car and by turning the steering fully left reach the left front and fully right for the right bleed nipple. Clutch can be either done when rear on ramps or once car back on the ground. Spray some penetrant onto the nipples and use the correct spanner. Do not open the bleed nipples too far, try not to shear them off and do not over tighten when refitting them. Aim to get about 250ml out of each bleed nipple that way you will have flushed out the old fluid. KEEP THE RESERVOIR FULL OF FRESH FLUID AND KEEP REFILLING IT AS YOU BLEED. Try not to press the pedal down further you would normally when braking to prevent damage to the master cylinder seals. Vacuum or pressure bleeding is a better way to do it.
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I've known the basics but great additional advices there, thanks!
I've been wondering if leaving car in reverse overnight or so, can damage the gear/spring, as it's a push-down one, not instead of 6th gear or so. I leave in 1st gear, even if parking up or down hill, to avoid possible damage.
 
audifan said:
A brake fluid service is a flush, refill and bleed of the DOT4 brake fluid. It should also contain a clutch flush and bleed but quite often this is not carried out.
Click to expand...
I think this is exactly what’s been done to Audrey - the braking system was flushed through but the clutch feels spongey and has a lot of travel. A job for when I’m in my new house with workshop- where is the clutch bleed nipple?
 
Clutch bleed / flush is probably the easiest bleed job to do. If you look at the top of the gearbox to the rear you will see the black slave cylinder and the nipple is on the top of it.
manual page image..
1618082271588.png

Was looking for a photograph but could not find one.


Just be careful as it is plastic not to shear the nipple off.
 
Please correct me, but I cannot recall seeing clutch fluid service mentioned anywhere in the A2 service book. I do see “hydraulic fluid level check” at 40,000 miles but don’t know what that refers to
 
@andrewparkeruk Dealerships knew it was a shared reservoir so when the brakes were due a fluid service the clutch was included. Most cars have individual reservoirs for brakes and hydraulic clutch. Whether it was space saving, weight saving or cost saving Audi chose to utilise the single reservoir for both functions on the A2. Brake fluid should be changed every 2 years.
 
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So, finally I've had the time to change the brake and clutch fluid, but then I've noticed the front and rear bleeding valves are different sizes. Rear small is like 6mm, front big one is like 10mm. Of course I couldn't find the 6mm one, so first I have to go to halfords.
Left pic front, Right pic rear.
Is this normal? Also the rear ones looks kinda rusted in, can't even see the threads, so I've sprayed wd40 on all. I've read those can break, don't want that for sure. Cheers.
 

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