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Brake fluid has not been changed for some time so I borrowed a tester from a neighbour and it is showing increasing moisture content so overdue to be replaced.

I jumped the gun and bought a cheap pressurised brake fluid bleeder. Not really like me but I thought why not?

So any little traps waiting for me to fall into, or is it as simple as doing it the old fashioned method with a mate on the pedal? I guess I should also do the clutch cylinder while I'm at it. (1 Bar be enough to do the job)

ErWin says for normal bleeding.

1. Rear Left (Curb side/RHD)
2. Front Left
3. Rear Right
4. Front Right
5. Clutch cylinder

Which left... LOL. Viewed for the front of the car or the drivers seat? (I've assumed looking at the front of the car)

sometimes its easier to reverse bleed the clutch cylinder ( from the nipple push fluid towards the brake master).
Id wire clean around nipples, or at least spray some wd night before. The the hex on the nipple starts to round, use locking pliers and heat up the area and spray wd while its hot. I had one nipple like that.

If you have one person bleeder kit, it's easy.

Left side should be the side looking when you sit in the car.

amer6R wrote: Mon Jul 08, 2024 7:03 pm
Id wire clean around nipples, or at least spray some wd night before. The the hex on the nipple starts to round, use locking pliers and heat up the area and spray wd while its hot. I had one nipple like that.

If you have one person bleeder kit, it's easy.

Left side should be the side looking when you sit in the car.

Cheers. I'm already on it. Bought some penetrating oil and I've brushed the nipples, followed by and blast of the oil. Done them a couple of times to give it time to soak it. Be a day or two before I can get to it so I'll soak them some more. I also have discs and pads for the rear to do so car is getting so TLC.

'For me' (not all of us have the same skills or interpretation of circumstances), the best brake fluid bleed/renew system is with a one-way valve (single mechanic system) and bleed hoses that fit perfectly to the bleed valves/bleeders (without easy-on hoods on bleeders).
'12 full strokes' of the brake pedal are sufficient for each wheel, Erwin indicates 5 times/full strokes, and repeat as many times as necessary, but I tell you that 12 is better to work just what is necessary...
Same one-way valve system for the clutch cylinder, you just have to follow Erwin's instructions but with the one-way valve.

The pedal/s will feel just like new and you will have renewed/bled the brake system bordering on perfection.

- Personally, I would not connect any type of pumping device/artifact to the brake system except the official VAS XXXX.
- You can also use diagnostic tools to bleed the brake system, but it is not necessary at all.
- If you have to bleed the ABS pump due to its renewal/disconnection/failure, you must use a diagnostic tool.

Why not use the pressurized bleeder?
There's nothing wrong with them. Just don't pump them up too high. Last I read a 2 bar pressure is what is needed.

Vacuum works just as well too.

I've used the one-man bleeder kits with mixed success.

I have been using Gunsons Easibleed kits for many years, just make sure that you fit the correct sealing washer to the chosen cap - as there is typically 2 to suit 2 reservoir thread sizes using one cap size.

It is always best to test the bleeder kit without any new fluid in it, before filling it with new fluid - doing that will save fluid leaking out and possibly onto painted surfaces.

I'd suggest replacing the pads and discs first as doing that will have the pistons as far back in their bores before replacing the fluid, so avoiding the need to remove new fluid from the reservoir AFTER bleeding and then replacing the discs and pads.

Make sure that you have a piston wind back tool to wind the rear pistons back in before fitting the new discs and pads, at this point, you might find that the piston(s) can not be wound back fully, which could indicate that a piston or pistons have corrosion built up on the piston surface, and if so, would require the piston(s) to be removed, cleaned/polished and refitted, or if in very poor condition, the piston would need replacing or the calliper replacing if you are not up to repairing/servicing a brake calliper.

I've ended up, over the years, collecting far too many/much kits for replacing brake fluid, I've even bought a used brake master cylinder complete with reservoir, I have repurposed the reservoir as a test tool for my pressure bleeder kits, the reservoir cap has had its vent sealed up and that cap get used to stop brake fluid escaping from an opened brake system. I've also got a couple of vacuum bleeders, they work well if you initially remove the bleed nipples and coat the threads in a suitable grease to stop air getting drawn in and confusing you/me by having micro bubbles in the removed fluid!

Take care when doing the clutch as its master cylinder is plastic and you could end up snapping the plastic bleed nipple or cracking the master cylinder body.

I plan to change the brake fluid on both our cars very soon, I always buy DOT4 "+" fluid, ie not basic DOT 4 but enhanced DOT 4, possibly named DOT 4 ESP or some other name to indicate that it is suitable for use with modern braking systems.

Edit:- I'm not trying to say that this task is "rocket science" it just needs you to take care, very doable by an average DIYer.

DOT 4 LV or Low Viscocity. Needed for ESP.

dont forget to wear gloves and swap for new ones if they tear.
if you get brake fluid on your hands for too long, your skin on hands will get wrinkly ( like when you leave them in water for too long), and feel really dry .

Single-use sterilized syringe.


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...and then when you finish bleeding you are not obliged to 'meticulously' clean the chosen pumping system, because otherwise the next bleeding or renewal of the brake fluid will contaminate the new brake fluid.

ciclo wrote: Tue Jul 09, 2024 8:34 am


Single-use sterilized syringe.


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...and then when you finish bleeding you are not obliged to 'meticulously' clean the chosen pumping system, because otherwise the next bleeding or renewal of the brake fluid will contaminate the new brake fluid.

Hey ciclo,
Is this really a fabric inner fender liner on a polo or that is a golf?

I've found that over the past maybe 3 or 4 years, VW Group dealership's parts departments, have stopped stocking these cans of brake fluid, so initially I just bought them from online traders, then moved onto buying other brands of the same (VW Group) spec brake fluid.

The comments that I tended to get when asking to buy brake fluid in small cans was "our workshop now ever buy in brake fluid in bulk", ie larger containers, which was annoying as I had considered that the VW Group branded cans of brake fluid were usually quite good value for money when compared with what the aftermarket was asking for similar spec'd brake fluid.

They are images of our Golf 7.5, for the 6R I did not take images of the brake fluid change. In regards to renewing and bleeding the brakes, the procedure I used is practically the same.

I don't remember the exact date, but between last year and this year I bought several cans of VW brake fluid like the one shown in the images at the official VW store where I live. ...and I am fully convinced that they are still selling them today.

ciclo wrote: Tue Jul 09, 2024 8:34 am


Single-use sterilized syringe.


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...and then when you finish bleeding you are not obliged to 'meticulously' clean the chosen pumping system, because otherwise the next bleeding or renewal of the brake fluid will contaminate the new brake fluid.

DIY vacuum bleed? Not sure of your process here ... but I like it.

No, it is not a vacuum system, I did the brake bleeding with the brake pedal and the one-way valve, the syringe attached to the bleeding hose is experimental.
Because I disconnected the brake lines to change the brake calipers, this syringe was used 'initially' to extract as much air as possible before bleeding by pressing the brake pedal. It is highly recommended because you avoid pressing the brake pedal more times than necessary.

In this case, what will really make the brake pedal feel good without a 'spongy' sensation is by bleeding the brake system through the brake pedal.

Sorry for the confusion generated, but the images available are always limited.

Cheers for the walk through and advice all really helpful. Thanks all.

OK. I now have a revised cunning plan!

I was going to bleed the brakes first and then do my discs and pads. However, as mentioned above it makes more sense to do those first, then bleed/flush everything through. Pressure bleeder was delivered this morning. It's identical to this but I picked it up for £25 off Ebay. I'm surprised how decent the quality is for the price.

https://www.amazon.co.uk/Bleeding-Bleed ... d_source=1

I picked up 2L of DOT4 at the weekend so should be good to go. Also printed off the destructions from ErWin "just in case"
With seized bleed nipples being mentioned It crossed my mind that you may be able to get stainless steel alternatives. So I'll have a Google later.