Air in the brakes?

[Chilli Girl]

Not Foxy but my other 2.  I've noticed that when I'm queuing and occasionally having to use the brake pedal lightly.  When I come to a slow stop, I notice that the foot pedal moves alittle further (only marginally).  Is this a symptom of air in the system?  Anything to worry about or not?  

[Joesson]

Not Foxy but my other 2.  I've noticed that when I'm queuing and occasionally having to use the brake pedal lightly.  When I come to a slow stop, I notice that the foot pedal moves alittle further (only marginally).  Is this a symptom of air in the system?  Anything to worry about or not?  

Hi Jane
I wouldn't worry about that symptom. I suggest what you describe is " caused" by your driving style. I doubt that you apply the brakes hard very frequently. As I've mentioned elsewhere hydraulic disc brakes are self adjusting. I suggest that next time you startup give the brake pedal several very firm applications. You will likely notice the the pedal movement is reduced after this exercise. You could make a habit of doing this particular pedal dance as a routine depending on usage and how the pedal feels.

[Chilli Girl]

Thank you Tony, I'll do my dancing routine after I start her up in the morning and do abit more hard braking during my journeys in future but I'll wait til the frost disappears in the morning tomorrow before I do

[paulj]

Looks like you have a good driving style and a couple of advanced driver tips will help you more.

Tip1, as part of the "pre flight checks" depress the brake a few times checking for brake pressure.

Tip2, when coming to a halt, slightly release pressure from the brake for a smooth stop.

The most important tip I can give is unrelated to the post - make progress whenever it is safe to do so!!!

[Joesson]

Indeed, infrequent application of the brakes shows awareness and use of the accelerator to control "progress", as it does have an effect when used in either direction, a point not widely appreciated. As I necessarily follow cars, when unable to "make progress" I do notice that many drivers use their brakes very frequently, at any opportunity and sometimes for seemingly no reason.
For such drivers your tip 2 is perhaps a step too far as they are totally reliant on the brakes for stopping before impact.
And yes, making progress, although speed limits are maximums and there is no minimum limit, in general making progress when possible, I suggest, would save some frustration for those behind that get frustrated in such situations.

[thetyrant]

When was the brake fluid last changed or bled ?   brake fluid goes off with age as it absorbs moisture so should be part  of a service routine, every 2 years maximum ideally but i tend to do mine more regular due to increased stress from track use and high temp pads etc.

Brakes always feel better after service/strip/clean and bleed which is so overlooked these days!

Could be other things like sticking sliders/pads etc but all depends when it was last looked at i guess.

[Petrus]

Indeed, infrequent application of the brakes shows awareness and use of the accelerator to control "progress", as it does have an effect when used in either direction, a point not widely appreciated. As I necessarily follow cars, when unable to "make progress" I do notice that many drivers use their brakes very frequently, at any opportunity and sometimes for seemingly no reason.
For such drivers your tip 2 is perhaps a step too far as they are totally reliant on the brakes for stopping before impact.
And yes, making progress, although speed limits are maximums and there is no minimum limit, in general making progress when possible, I suggest, would save some frustration for those behind that get frustrated in such situations.

Anticipative driving. Looking ahéad and actually régistering what you see.

I find it very worrying, almost scary, to all the time see that I have lifted and slowed down for something ahead whereas two, three cars ahead stamp on the brakes way later for the same.
It means that they will not see/register me either.
It is something stemming form the decennia I was on motorbikes for daily transport as that was pure survival.

The observation about a maximum speed is also só spot on.
It means NO FASTER and ónly that when circumstances permit. From fog to traffic density thereis a myriad of situations that prohibit the max. speed.
Even when circumstances permit it is not an obligatory speed; the cabrio is relatively véry populat in the UK and driving top down at leisure belów the max permitted speed is totally acceptable travel.

There is a little known, even less read book by Pat Moss and Eric Carlsson;
https://www.amazon.com/Technique-Driving-Carlsson-Erik-Moss/dp/B000J3SMR6
about driving techniques. Don´t look at the price, that is silly.
An entertaining gem. The basics they explain are só basic yet today seemingly forgotten.

[Chilli Girl]

When was the brake fluid last changed or bled ?   brake fluid goes off with age as it absorbs moisture so should be part  of a service routine, every 2 years maximum ideally but i tend to do mine more regular due to increased stress from track use and high temp pads etc.

Brakes always feel better after service/strip/clean and bleed which is so overlooked these days!

Could be other things like sticking sliders/pads etc but all depends when it was last looked at i guess.

I'll look back and see if it's had a brake fluid change yet, the cars 5 plus years old now so I'll see if it's had new fluid in that time, the mileage is still only 17K but I'll take a look at the records, thank you.

[Joesson]

@Chilli Girl
I believe you have the Mazda variant of the Ford Fiesta, my Ford service schedule advises brake fluid change at 2 yearly intervals but it is an "extra"
to the service schedule at the main dealer and they always my approval for the extra.
To preempt any protests about my choice of a MD in preference to an independent, they give me continuing Ford (AA) breakdown cover and as this is worth North of £70 and the independents I have considered are  not that much less than the MD I have stuck with them .
Similarly, so as not to provoke another discussion about the merits of the various break down organisations my 2 was with Start Rescue with whom I had 1 call out and no problems. This year after some consideration and unsure of the continuing status of the Ford service, as my daily is over 90k and approaching a 10th birthday, I chose Auto Aid and am now covered for Any ( small) vehicle that I drive. That means that my Daily is covered twice. Only "problem" is that I will now drive only 16 miles a week!

[Chilli Girl]

Yes, I agree with Petrus here regarding the motorcycling theory - I do look well in front and take my foot off the accelerator perhaps too early sometimes and perhaps maybe this is why sometimes I get tailgated, although I do touch the brake sometimes just to let people behind know I'm slowing down. Especially important when I was on two wheels as wouldn't appreciate someone throwing me off from behind!

[Petrus]

Yes, I agree with Petrus here regarding the motorcycling theory - I do look well in front and take my foot off the accelerator perhaps too early sometimes and perhaps maybe this is why sometimes I get tailgated,

You get tailgaited because those behind give their hurry a higher priority than road safety.

[Jimbo]

Yes, I agree with Petrus here regarding the motorcycling theory - I do look well in front and take my foot off the accelerator perhaps too early sometimes and perhaps maybe this is why sometimes I get tailgated,

You get tailgaited because those behind give their hurry a higher priority than road safety.

I sometimes tap the brake pedal enough to flash the rear brake light, generally puts them off driving too close.

[Chilli Girl]

Well, update, I did the dancing routine on the foot pedal this morning and it seems to be quite a bit better than it was.  I'm going to have a look now and see if it's had new fluid since new.

[Joesson]

Well, update, I did the dancing routine on the foot pedal this morning and it seems to be quite a bit better than it was.  I'm going to have a look now and see if it's had new fluid since new.

I'm sure you are aware that such advanced driving tips 😉 are no substitute for correct and complete maintenance and so  why changing brake fluid at every other (regular) Service is not just part of that service, I really don't know. Although it may be the case that some sort of moisture meter is used to test the fluid and a change is only offered if necessary, But, I doubt that, certainly not the case with Ford in my experience, they do just go by time elapsed and offer it as an option.

[Mr2paul]

Yer that,,,,,n some great advice there. Don't worry. It ain't gonna break lol... But

[Chilli Girl]

Just checked - brought car new in 2015 and on its second service in 2017, it had brake fluid done at 7,700 miles.  I'm now on 17,700 miles and 3 services on and no mention of brake fluid change again.  ? 

[Joesson]

@Chilli Girl
Thought I would have a look at what is said on the subject. First hit was Kwikfit:

"Our trained brake technicians will use a pressure bleeder to perform the brake fluid change – this pumps a constant supply of new fluid under pressure into the brake fluid reservoir to avoid air getting into the hydraulic system. Starting with the brake in most need of attention (the most contaminated)and then moving around the vehicle in a sequence depending on the braking system fitted, the old fluid is then bled out at the bleed nipple on each brake, until clean fluid is seen in the bleed bottle. The new fluid pushes out the old fluid, which is then disposed of."

I'm not aware that "the brake in need of most attention ( the most contaminated) can be detected or that the fluid would be different brake to brake.



"Did you know that changing car brake fluid is not typically included in a vehicle service? That's why it is important to make sure your brake fluid is in good condition and replaced regularly to reduce the chances of brake failure. At Kwik Fit, both our interim service and full service packages include a check on your brake fluid to ensure that the boiling point and general condition is acceptable. In addition, if you know you vehicle needs replacement brake fluid, you can add this as an additional extra at checkout when you purchase your service online."

[Joesson]

Next up Halfords:

"A vital part of car maintenance is to change your brake fluid to ensure safety of brake components. Most manufacturers recommend that you change your brake fluid every 24 months or 24,000 miles, whichever is sooner."

[Joesson]

And from Emanuel on line.com:

"It is good practice to periodically replace brake fluid based on the manufacturer's recommended intervals. However, the lifespan of brake fluid depends largely on how the car is driven. Cars that see lots of miles will need more frequent fluid changes. A four to five-year change interval is recommended by most manufacturers. If the brake fluid is contaminated with water or other substances, it should be changed before the car is back on the road.

It's also a good idea to replace the brake fluid when doing significant repairs, like replacing the master cylinder. Changing the brake fluid is easy at that time since the system will need to be bled to remove air anyway.

These types of brake fluid are hygroscopic, meaning that they absorb water. Each time you take the master cylinder cap off, a small amount of water contained in the air will be absorbed, reducing the overall lifespan of the fluid."

My understanding is that it is the hygroscopic nature of brake fluid that reduces its functionality.

This quick look at three different sources of information and the contradictory comments suggest that there is some scope for interpretation that is exploited by those offering "service" for motor vehicles.
I have not read all of the fine print in my insurance documents but I feel reasonably certain that there will be a clause stating the vehicle is to be serviced in accordance with the manufacturers recommendations.
The question that arises from that could be that if you have your vehicle serviced by a Main Dealer that should be sufficient.
If they offer brake fluid as an extra and it is declined the onus of responsibility is back on the owner.
If you have your vehicle serviced by a MD and they do not offer a brake fluid change as an extra then they are accepting responsibility for the fluid being in accord with the manufacturers requirements.

[scm2004red]

For the record, your MR2 "Service and Warranty" booklet, recommends, in addition to the normal servicing routine, an " Additional Replacement" of brake fluid every 2 years.

[thetyrant]

Just checked - brought car new in 2015 and on its second service in 2017, it had brake fluid done at 7,700 miles.  I'm now on 17,700 miles and 3 services on and no mention of brake fluid change again.  ? 

Sounds like its well overdue a fluid change and probably worth getting a full brake service at the same time, as in pads out and cleaned up, regreased etc and then all slider post cleaned and greased etc to make sure calipers are nice and free, as well as doing the fluid to make sure its tiptop.

 It tends to a gradual drop off in performance with brakes which you dont often notice until it gets really bad.

[Joesson]

Just checked - brought car new in 2015 and on its second service in 2017, it had brake fluid done at 7,700 miles.  I'm now on 17,700 miles and 3 services on and no mention of brake fluid change again.  ? 

Sounds like its well overdue a fluid change and probably worth getting a full brake service at the same time, as in pads out and cleaned up, regreased etc and then all slider post cleaned and greased etc to make sure calipers are nice and free, as well as doing the fluid to make sure its tiptop.

 It tends to a gradual drop off in performance with brakes which you dont often notice until it gets really bad.

But how many garages would put the required amount of TLC into such a brake service. A sticky part "oh needs a replacement" is more typical I understand.
Such levels of care are more typically provided by diy mechanic's, and that is because we are unsure of what we can get away with and so do that bit extra, whereas the professional knows what they can get away with.

[Bossworld]

Jane - back to the original crux of your post, I spent a little time Google searching 'brake creep' last night as I think both my MR2 and Mini do something like this.

It seemed it's not beyond normal (in that if the engine was off, you'd quickly find a definite 'stop' point), but with the engine on, it can go further.

Possibly something relating to servo assisted brakes.  Just one thread as an example but similar points to everything above https://www.pistonheads.com/gassing/topic.asp?h=0&t=651328

[Petrus]

"Our trained brake technicians..."

Well, that is a relief  ;-)