Brake fluid testing

[Ian Comerford]

For years I have religiously changed brake fluid every two years because that was the wisdom; it’s hygroscopic and so will absorb moisture and become less effective.  Now you see many garages testing brake fluid and not changing it if the water content is less than 2% or so.  Which makes me think I buy a tester and see if it saves me time.  Thoughts?  Anybody do this already?

Ian

[Roy M]

Testers are really cheap but I don't know how accurate they are so still change fluid every two years - I'm fairly certain I'm overdoing it but would need to find something which can be confirmed as accurate.

As an example - I get different pressures from every tyre pressure gauge I've got and don't KNOW which is actually correct.

[Mobydick]

I have a fluid tester - it works really well. I think it s a Gunson - it must be 15 years old now. 

I don’t see newer cars replacing the brake fluid every 2 years. 

[R2D2]

I have one of those testers and the fluid always checks out ok after 2 years. That said, I have one of those pressure bleeders which makes the task so easy I actually enjoy changing the fluids! Every 2 years for me.

[Phill]

I'm feeling I should change my fluid  Haven't done it in my ownership, 14 years  Still brakes great though 

[jevvy]

3 minutes ago, Phill said:

I'm feeling I should change my fluid  Haven't done it in my ownership, 14 years  Still brakes great though 

Its probably safe to drink and splash all over your paintwork after 14 years, a nice vintage one might say

[R2D2]

the cloud of burnt rubber at the last equinox (soltice) run did certainly prove that your brakes still work Phil!

[Phill]

1 hour ago, R2D2 said:

the cloud of burnt rubber at the last equinox (soltice) run did certainly prove that your brakes still work Phil!

tyres not so much now though....

[David Gander]

This ‘deja vu’ moment as the recent input on the pro’s and con’s re scissor lifts and opening the car doors restricted by the posts on two-posters got me thinking on when I last changed the brake fluid and having the Wife up in the air pumping the pedal!! Cannot remember so will do it soon....interesting that Phill has overlooked this and suffered no undue effects after 14 yrs!, I normally record all maintenance and the fact this doesn't appear on the list  makes me think that I’ve done a ‘Phill’!

[Chris_911]

I try and stick to two years regardless.

It's a good process to go through and gives an opportunity for a good check. If nothing else it keeps my nipples nice and free 😳

[David Gander]

I’m all for ‘’free’d’’ nipples.....have not looked at mine recently come to think about it, and haven’t seen my Wife’s ones recently either.........hopefully the Turbo’s ones are suitably free’d and available to twiddle with soon?

[Nige]

I don't plan it as maintenance but there is usually something that requires the fluid to be drained/changed.  Don't think it's every 2 years though.

Probably should do it on the rest of the fleet as well.

[Phill]

Im interested to know how often people change the brake fluid on their dailies? I've had my fiat 500 for 8 years and had a Nissan xtrail for 11. Never changed the fluid on them and never had any brake issues. Do new cars have a fluid change factored into their services?

[Busybee]

26 minutes ago, David Gander said:

I’m all for ‘’free’d’’ nipples.....have not looked at mine recently come to think about it, and haven’t seen my Wife’s ones recently either.........hopefully the Turbo’s ones are suitably free’d and available to twiddle with soon?

🙈🙉 David, you really need to twiddle more 🤗

[Ian Comerford]

39 minutes ago, Phill said:

Im interested to know how often people change the brake fluid on their dailies? I've had my fiat 500 for 8 years and had a Nissan xtrail for 11. Never changed the fluid on them and never had any brake issues. Do new cars have a fluid change factored into their services?

I think most now say to check rather than change and if the test is not good, change it.  Condition based maintenance then.

[jevvy]

Brake fluid is not like engine oil, it doesn't 'circulate'

Using a device you dip into the brake fluid reservoir to determine the condition of the brake fluid in your entire braking system is like licking the outside of a vacuum packed slab of Roquefort cheese and thinking you know what it will taste like.

[Ian Comerford]

20 minutes ago, jevvy said:

Brake fluid is not like engine oil, it doesn't 'circulate'

Using a device you dip into the brake fluid reservoir to determine the condition of the brake fluid in your entire braking system is like licking the outside of a vacuum packed slab of Roquefort cheese and thinking you know what it will taste like.

Good point, makes sense.

[Richot1989]

Modern cars use DOT5 spec brake fluid, which, I believe is not hygroscopic (silione based, I believe)and therefore doesn't need to be changed as regularly as quoted for the hygroscopic spec brake fluids (DOT 4 and lower)

However,  I am open to being corrected on this.

[Dr Rock]

https://www.hemmings.com/blog/2013/12/06/tech-101-brake-fluids-whats-different-about-them-and-why-should-you-care/#comments-block

[MarkJ]

ironically whilst watching an episode of wheeler dealers last night, clever Edd china talked about brake fluids and when they should be changed. (2yrs or 40k miles I think)  I didn't know the performance fluid (Motul etc) that us trackday guys use absorbed moisture quicker than your regular brake fluid and so should be changed more often (even if not tracked).

jeez Phil, 14 years!? and you still get a firm pedal feel?

[Phill]

To be fair, when I swapped to Boxster brakes, most of the fluid leaked out but that was still a long time ago. Like many routine maintenance things I think there is a lot of scare mongering. However, to keep those happy that may find themselves driving in front of me I shall change it soon. Can't do any harm.

[angusb]

23 hours ago, Phill said:

To be fair, when I swapped to Boxster brakes, most of the fluid leaked out but that was still a long time ago. Like many routine maintenance things I think there is a lot of scare mongering. However, to keep those happy that may find themselves driving in front of me I shall change it soon. Can't do any harm.

oHHH Definitely not a scare mongering thing,Phill on any car, never mind 911 performance it a routine critical maintenance.

[Phill]

On that we will have to agree to disagree. I note that no one has stated they change their brake fluid routinely on their daily drivers and I have never once heard anyone tell me that when they have had their car serviced, new or old, that the garage changed their brake fluid. Bled, yes, changed, no.

[Chris_911]

8 minutes ago, Phill said:

On that we will have to agree to disagree. I note that no one has stated they change their brake fluid routinely on their daily drivers and I have never once heard anyone tell me that when they have had their car serviced, new or old, that the garage changed their brake fluid. Bled, yes, changed, no.

I change my fluid on my daily.

I once paid a local BMW specialist to change the fluid on the BMW I had at the time. A little while later it became obvious that the fluid cylinder hadn't been accessed so I tested the fluid. My tester lit up like a Christmas tree. Suffice to say I'll never use that indy again......Grrr.

[Dr Rock]

Daily gets changed and 911 (ATE Super Blue) every year by GCR. When i buy a car I bleed a little bit out of each calliper, partly for peace of mind, partly to check the bleed nipples will undo