Brake Fluid - Replacing

[hd840]

A high of number of vehicle manufacturers (Germans included) state that Brake Fluid should be changed every 2 years.

Does any one know if that is 2 years due to the ageing/moisture process over time, or is it a mileage and therefore usage related thing (ie.renew every 20,000 miles or so).

 

[television]

Its because is hygroscopic, In English it absorbs moisture

 

[hd840]

Its because is hygroscopic, In English it absorbs moisture

Yes I know that (and I know what hygroscopic means thank you) but that is not what I asked.

 

[swells]

A high of number of vehicle manufacturers (Germans included) state that Brake Fluid should be changed every 2 years.

Does any one know if that is 2 years due to the ageing/moisture process over time, or is it a mileage and therefore usage related thing (ie.renew every 20,000 miles or so).[/quote

He did answer you

 

[rf065]

Yes I know that (and I know what hygroscopic means thank you) but that is not what I asked.

Charming!

Russ

 

[television]

Yes I know that (and I know what hygroscopic means thank you) but that is not what I asked.

Well if you know that how can it be a mileage thing ?

 

[hd840]

Well if you know that how can it be a mileage thing ?

I was only wondering if the condition was escalated by usage and hence the mileage aspect ...ie. more mileage =more usage= more fluid breakdown.
Sometimes when manufacturers state a time period they assume mileages per annum of (say) 9,000 or so.
By your last answer you presumably think it is only age related
...oh well thanks anyway.

 

[television]

Yes it is an age thing, I added the English meaning as we have many overseas members, truthfully many cars never get the fluid changed through one reason or another, my Volvo is one example

 

[hd840]

Yes it is an age thing, I added the English meaning as we have many overseas members, truthfully many cars never get the fluid changed through one reason or another, my Volvo is one example

Thanks for explaining why you added the English meaning...I honestly did think you were patronising me...sorry for the misunderstanding.

As a matter of interest how important do you think it is to religiously change it every 2 years anyway...the reason I ask is that I am retired now and only do around 4,000 miles per annum so I would be changing it at 8,000 mile intervals which seems too often... unless of course it really is that important and must be adhered to due to effect of water content on seals, ABS, etc. with fluid over 2 years old regardless of usage.

Thanks.

 

[television]

I do ask myself sometimes if this is not a sales tactic. I have never noticed any difference in braking on a car that has never had the fluid changed. The brake fluid that sits in the pipes cannot take in moisture, the header tank only has a tiny hole.
My SL500 is 7 years coming up soon and on the original fluid, and there is nothing mentioned in the service book about changing it.

Changing the brake fluid was not a thing that one ever had to do some years back

 

[Ron Palfrey]

Our summer car is a convertible and does the same sort of mileage as yours, 4,000 p.a. The fluid in that is changed every 2 years because, for the very minor cost involved, I prefer not to invite problems with the ABS system, as they could prove to be expensive.

 

[hd840]

Our summer car is a convertible and does the same sort of mileage as yours, 4,000 p.a. The fluid in that is changed every 2 years because, for the very minor cost involved, I prefer not to invite problems with the ABS system, as they could prove to be expensive.

Yes valid point Ron...I am thinking the same thing...maybe false economy not to do it

....but... what television (Malcolm) says is also true to my mind.

Oh what a dilemma....I guess I will get a quote for the work from an independent (dealer quoted 1 hour job at total cost of £80 plus vat...this is what started off my train of thought as to whether really needed) and take a view at that point as to ecomnmics.

Thanks everybody for your time in responding.
Hayden

 

[Number_Cruncher]

>>dealer quoted 1 hour job

Although I'm going back to 1990 or so, and quoting from Vauxhall experience rather than MB, but a brake fluid change used to be allocated 0.3 hours, i.e. 18 minutes. If the car is already on the ramp for, say, an oil service, it's easy enough to make 12 minutes bonus on the job.

So, quoting an hour is somewhat steep.

 

[rf065]

I got charged £85 when mine was done as part of the B service, that included the brake fluid as well. The dealers charge about £100 per hour, so probably 30-40 minutes labour plus fluid?

Russ

 

[djb]

Moisture & Fluid

I have been told it is that moisture travels through the rubber flexible pipe section. As brake fluid has its water content raised it lowers the boiling point. Thereal problem apparenty is when the brakes are applied that "moist fluid" goes ito the calipers / brake cylinder, where during vigorious braking it then boils! with immediate loss of braking effect.

Many years ago Girling use to have a test kit that a little fluid could be bled off & the boil point tested.

 

[Parrot of Doom]

Changing the brake fluid was not a thing that one ever had to do some years back

To be fair Malcolm, there is a noticeable difference in colour between old and new brake fluid.

 

[television]

To be fair Malcolm, there is a noticeable difference in colour between old and new brake fluid.

Thats true, but the same can be said of the fluid in a autobox, these fluids are highly corrosive and soon change colour.

I am not against it, it cannot hurt any components in the braking chain, I just think that its a bit over done

 

[muller1]

Brake fluid change (or not)

Changing the brake fluid was not a thing that one ever had to do some years back[/QUOTE]

Hi there Television.
I am sure that it is a money thing.
Money for the garage I mean.
I had a Toyota Landcruiser for 19 years and put over 180,000 miles on it and NEVER changed the brake fluid, and it braked better when I sold it than it did when I took delivery of it new.
I would say to change the fluid ONLY when the braking falls below par and everything else has been checked.
Any fluid would work in the brake system even flat beer or coke but the corrosion would be the only thing to consider.
The oil in the auto box is very similar to brake fluid as is the power steering fluid and you do not hear the makers saying to change it every couple of years.
I have changed the fluid in Allison transmissions on anchor handling work boat winches due to moisture ingress.
This was due to the unit being floged to death for 24 to 40 hours non stop, getting smoking hot then stopped for a few days and getting cold and the contraction drawing in moist sea air and then water builds up in the unit and boils off the next time the winch is worked hard and due to the steam generated in the system the clutches start to slip and at this point you know it is time to oil change.
The only thing that can happen in a vehicle is if the brakes are used so hard as to get the fluid very hot, ie above 212f or 100c then any water/moisture present at the caliper piston will boil off and reduce the effectiveness of the hydraulics hence a POSSIBLE reduction in braking effect.
Sorry this is so long.

Mike

 

[carabind]

OK Mike, but waiting till it falls below par may be a bit late . When would you know this?? You may not realise the fluid has gone off till you come to do an emergency manuvoure and end up parked in someone else's boot. You compare brake fluid to tranny fluid. If a tranny fails due to fluid contamination, then that's bad and expensive. If brake fluids fails, that could possibly be fatal. That said, I know where you're coming from, but with ABS pumps now standard across all new cars for the last couple of yaers, these are particularly sensitive to particles containd within old fluid. To keep warranty, I'd stick with 2 years (or whatever the manufacter says), after that 2-4 year intervals depending on mileage and driving style is far better than ignoring completely.
Each to their own, but I wouldn't like my wife to be driving up a steep windy hill whilst you were coming down it in your 19 year old landcruiser that might be fully laden and pulling a trailer! Do you see where I'm coming from?

 

[television]

Just discussing this without bias one way or another.

I have never heard of an accident where it was said that the brakes failed, and that the fact that the fluid had not been changed, was a contributing factor.