Brake Fluid

[ddave05]

Hey there,

I had a look at my service schedule and it appears that the brake fluid needs to be replaced sharpish (it's been three years since it was last done!). The question I have is that because it has ABS with ESP, does the method of changing the fluid differ to normal? Would it be advised to purchase a bleeding kit, or just pump the pedal and put a tube from the bleed nipple to a collector in the conventional way? And is there an order to the fluid change (i.e opposing wheels)?

I think ill buy a bottle of dot 4 and do the job over the weekend, i just want to be sure im doing it correctly.

[snapdragon]

It is quite easy to do, especially after the first time.

The dealer is supposed to activate ABS pump and valves but they don't bother/can't be bothered in my experience. So if you don't bother either does it matter that much? Try and use the ABS once a year, which should be easy in winter to keep things working.

I do mine every time I change the pads. It takes 15-30 mins.
I use a bleeding tube with a one-way valve in the end into a glass jar.

You can do the brakes easily with 500ml so 1litre will be plenty for a first timer.

It is best if you can empty the reservoir with a syringe and refill with new fluid at the start, but if not, pump the brakes 10 times and refill.

You can slowly sink the pedal down with your foot at least 10 times before needing to top up the reservoir.

When you top up the reservoir, avoid entraining air into the fluid as it will remain suspended and get drawn down into the system, a mesh filter appears to be in place to help prevent this.

There is an order specified in the VW documentation and it id different from Haynes, I think the best thing to do is the rear passenger, followed by front drivers' then rear driver's followed by front passenger.

You may also like to change the front rubber brake hoses, these are ~£9 from eurocarparts and really improved my brake feel as though the old ones were ballooning.

[peter cutmore]

I changed my brothers ABS unit a few months ago I started to bleed from furtherest away a vacumn bleeder was used with good results only thing is you need alot of fluid but it is worth it

[kenney]

It is best to pressure bleed the system,however,no problem in doing it the old traditional way, roughly 0 ,25lt per wheel Bleeding sequence:
1 - Front left brake caliper
2 - Front right brake caliper
3 - Rear left brake caliper
4 - Rear right brake caliper

[ddave05]

How tricky is the hose job? I haven't looked into that but it may be worth changing. Not bothering with VW to do the job - they want to charge half an hours labour (£40-50) for such a simple job!

I was just going to use an open tube for the drain of fluid from the caliper, but I think ill go and invest in a tube with a valve for the job. cheers for teh advice

[kenney]

Subsequent bleeding
This requires the assistance of a second mechanic:
– Depress brake pedal firmly and hold.
– Open bleeder valve on brake caliper.
– Fully depress brake pedal.
– Close bleeder valve with pedal held down.
– Release brake pedal slowly.

[snapdragon]

How tricky is the hose job? I haven't looked into that but it may be worth changing.

Mine were flagged as perished by VW's 'free' safety check. So I bought new ones and when I came to do the job I was ****** off as they looked perfect. I changed them anyway and the brakes felt much better than they ever have since I bought the car over 3 years ago.

The hoses are about 9" long with integrated metal threaded ends. They are held to the suspension at each end with a metal clip that pulls out with pliers or screwdriver.
Clean the area and threads with a spray solvent or WD40 or such like.
You then simply undo a union nut (11mm I think) which is captive on the metal brake pipe. Brake fluid will leak out and while you get the new hose and then you just offer it up to the metal pipe and thread the union nut onto the threaded metal sticking out of the end of the rubber hose.