Brake Fluid Change

[Martin-Sy]

As a starter let me say I don't normally do much on our cars these days.
Today was an exception and I changed the front discs and pads on my Seat Leon.
Easy enough but I also wanted to change the brake fluid. The book suggests its done every few years.
I didn't have an assistant to push the pedal or any special kit, but I do have a small electric vacuum pump.
Can I use this with a pipe from a bleed nipple and suitable sealed container to collect the fluid?
Bleed nipple =======>Container=======>Vac Pump

The sequence would be: Nipple shut, start pump, crack open the nipple for a few seconds, shut the nipple, top up the reservoir.
And repeat.
Would this work?
Is this a daft idea?
What about ABS stuff?

 

[Morrisman]

Sounds normal to me. I’ve done it that way a few times, as well as when bleeding a fresh system.
I’d not top up the reservoir until it’s getting fairly low, or you’re mixing old fluid with new continuously. But not so low you suck a bubble in….

 

[qwakers]

vacuum out the master first. fill with fresh fluid and go for it assuming your vac pump can handle brake fluid going through it.

or you could make yourself one of these:

 

[tom2207]

just buy a hose with the one way valve for about a fiver , cheap and cheerful , but they work ok , or use a bathroom cleaner spray bottle and a bit of hose , both will get you sorted on your own , or borrow someone to push the pedal for you.

 

[Martin-Sy]

or you could make yourself one of these:

Love it! An electric leg

 

[colnerov]

Love it! An electric leg

Thank you, I couldn't make out what I was looking at.

 

[Kram]

I recently bought one of these pressure bleed kits, appears to be good, but not had time to try it yet. https://www.amazon.co.uk/gp/aw/d/B0B36D5YS4

The problem with vacuum bleeding is the open bleed nipples will leak at the threads. It may work but you will see a constant stream of bubbles unless you take them out and wrap ptfe tape.

 

[Ross365]

The method I've often used, is cheap but actually works really well. For next to nothing, you can buy a plastic non-return valve, intended to be used on an aquarium https://www.ebay.co.uk/itm/122272844101 .

I just put one of those on top of the bleed nipple, and can then do one-man bleeding (all my bleed nipples have PTFE tape on the threads to stop air getting down there).

 

[Domdom]

I recently bought one of these pressure bleed kits, appears to be good, but not had time to try it yet. https://www.amazon.co.uk/gp/aw/d/B0B36D5YS4

The problem with vacuum bleeding is the open bleed nipples will leak at the threads. It may work but you will see a constant stream of bubbles unless you take them out and wrap ptfe tape.

That is precisely the same unit I bought to change the transmission fluid in my old Audi. One that has to be filled from the bottom. It works well enough, should be fine for brakes but pumping nearly 6 quarts (american bottles of fluid) takes a lot of pumping. 10 minutes to drain it all out but nearly twice that to get the new stuff in. This was thin CVT fluid too, not the thicker ATF.

Also worth noting it is aimed at transmission jobs and comes with gearbox fill plug adapters. It didn’t come with the adapters needed to go on the top of a master cylinder. I still use my old Eazibleed kit for that.

I do have one of those pneumatic kits which allegedly vacuums out from the bleed nipples. I would say it’s about as much use as a chocolate fire guard. Used it once and went back to the Eazibleed. Just doesn’t have enough suck to pull the brake fluid through. One of these https://amzn.eu/d/aq6Xh77

 

[Gareth J]

I do like the satisfaction of knowing there is fresh brake fluid throughout the system. However it's a grotty job. On an old car, I have for the past few years been experimenting with drawing out the brake fluid reservoir and refilling with new every time I change the oil. About annually. I have a cheap tester which, though probably inaccurate, does indicate that older fluid has more moisture in it. The reservoir gains a bit of moisture over the course of a year but doesn't look alarming, like the stuff that comes out of normally neglected cars.

I doubt there is enough fluid circulation/mixing to let this be a satisfactory ongoing maintenance but though it was an interesting experiment.

Soon, I intend to crack a brake nipple and compare the fluid that comes out to that in the reservoir. Be interesting to see if it's way different or somewhat similar to the reservoir.

 

[ms08]

I bought the Sealey pump up bleeder which was the best investment I made for brake bleeding.

 

[keithski122]

I use to do brake fluid changes all the time servicing cars, just put a pipe on the nipple with the end in a jar with fluid in the bottom and open the bleed valve, pump the fluid through using your foot making sure the reservoir doesn't empty, shut the nipple. Repeat for all wheels. Never got air in the system as it should only be pulling fluid.