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Brake fluid renewal

Hello,

I tried to change the brake fluid in a Ford puma at the weekend. I was surprised that the brake fluid was a straw colour. I read that it is easy to tell old from new fluid as it becomes darker. If new fluid is straw coloured, what does old fluid look like?

The car had an unknown history and Haynes recommended to change the fluid after two years, which is why I started but the fluid coming out was just as straw coloured as what went in, so I guess it was reasonably fresh and I was wasting my time!

I couldn't find the capacity in the Haynes book and Ford couldn't tell me either. I guess I changed 500ml. I've now got 500ml left in the 1L bottle I bought. How long before that becomes useless?

What is the best way to dispose of the old stuff? I can ask at my tip but I guess they'll just tell me to throw it in the non-recyclable skip: that's their standard answer!

I did my research here first and there was a worry that the nipples might have rusted in place. Three of them had. The fourth was very shiny so I guess it had been renewed. How do you replace the nipple? I guess you unscrew it and put the new one in quick, trying not to loose too much fluid in between?

What's the best way to cure this? Spray penetrating fluid on the nipple to help shift it? Should you put any grease on after wards to prevent it rusting in the future? I was weary about using oil and grease near the brakes.

I found out later that the some brake pipes had been replaced at the last MOT, so I guess the fluid was changed then (12 months ago). Do you have to drain down the system to replace the pipes? How does that work? (Only for curiosity, I won't be doing that myself!) Would the nipples have rusted up so soon in just one year?

The Haynes book said to do the change parked on a level surface. I thought I had removed the wheels in the past. That's what I had to do to work on those rusted nuts. Was that wrong?

I guess if you know where everything is and they move freely, you could work without removing the wheel or if you had a pit or hydraulic thing that they have in professional garages.

Thanks, Stephen.

Reply to
Stephen
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A darker shade usually.

Not really. At least now you know it's been done.

Very quickly. It is hygroscopic so as soon as you break the seal it starts absorbing water.

Take it to local council recycling place and empty it in the waste oil drum.

No. Just bleed it afterwards.

No. Whatever makes access easier.

Reply to
Conor

Conor gurgled happily, sounding much like they were saying:

The Saab's was pitch black...

Reply to
Adrian

Did you find they worked considerably better afterwards?

LOL.

Reply to
Conor

Conor gurgled happily, sounding much like they were saying:

Not hugely, surprisingly - although the clutch felt much nicer after changing the master, which died in the process of bleeding...

Strangely, all the bleed nips undid easily - although one of the rears needed removing completely to get any fluid to flow, due to bits.

Reply to
Adrian

it is always a good idea to remove the bleed nipple entirely, then you can power wire brush the threads, blow out the hole and coat the threads with grease, the grease is also useful to stop air getting between the threads and into the bleed tube (especially useful if you use a vacuum bleeding kit)

Reply to
Mrcheerful

Not that quickly, or at least not quickly enough to warrant throwing it away.

Providing the container is sealed, it can only absorb the water in the air in the container. Ideally if poured into a 500ml sealed container it could be kept until the next fluid change, or used if the brakes need bleeding for whatever reason.. The fluid in master cyls is exposed to air, and that fluid is only recommened to be changed within 2 years. Personally I'd put it in a smaller container and keep it. Mike

Reply to
Miike G

If you were truly mean you could heat it to over a hundred degrees and all the water would boil away and then use it.

Reply to
Mrcheerful

It's not a question of being mean IMO. The cost is not that important to me. It's just that I can't see any reason for throwing away perfectly good brake fluid, when it could be useful in the future. I certainly wouldn't use or boil off the water in fluid that had be left in an unsealed container for any length of time. Mike.

Reply to
Miike G

Well over 100deg hopefully or it's the worlds nastiest brake fluid.

Reply to
Duncan Wood

I was more musing than actually suggesting it :)

Mrcheerful

Reply to
Mrcheerful

"Duncan Wood" gurgled happily, sounding much like they were saying:

Which part of "the water would boil away" did you miss...?

Reply to
Adrian

None. If it's absorbed into brake fluid it won't boil away at 100degC. If it did you'd get bubbles every time your brakes got above boiling point. Fortunately solutions don't behave like that.

Reply to
Duncan Wood

BUT surely one of the reasons you change brake fluid is because at high temperatures the water (that is in solution) WILL turn into steam which will cause brake failure (a horrible feeling where the pedal can just be pushed to the floor, once it cools down everything seems fine again). (solutions can be easily separated, compounds are a bit more difficult)

Reply to
Mrcheerful

Yes, & if you look at the graph you can see the temperature it wil happen at,

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Reply to
Duncan Wood

So you can test your can of old brake fluid to check its quality simply by seeing what temp it will boil at.

Reply to
Mrcheerful

You can even by things that do just that & charge you a packet for the privilege.

Reply to
Duncan Wood

Works with battery acid too (H2SO4) Just boil it to clean it and get the water out. When white clouds start coming off the water has gone.

Reply to
Eric The Brave

Yes, I have seen those, useful to frighten a punter into getting a fluid change, I just change it for them anyway at something like the recommended frequency.

Along with hair and lungs?

Reply to
Mrcheerful

You might like to tell that to the distilling industries. They, poor deluded souls, are under the impression that separation of solutions with heat works quite well.

Ian

Reply to
The Real Doctor

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