[Jkredcliffe]

Had our i30 for just over a year now. We have had a few problems but main one is the brakes. I was approaching a round about when I lost all brakes. My foot hit the floor and nothing happened. Wasn't until brakes were pumped they slightly worked. Got my car off the road and 15 minutes later brakes work again. Now I'm worried they will cut out again. I have brake fluid. And brakes don't need changing. Have done a brake fluid change and just wondered if anyone else had come across this problem as hyundai are no use what so ever

[xiziz]

Only thing i can think of is checking that the pusher pins are properly lubed up, everything else seems to be in order. But the pumping would hon at the pins seezing or the ABS failing, but the latter should throw a code.

[tw2005]

Did the problem occur before or after the fluid change?

Were the brakes being worked hard and getting hot?

any evidence of fluid leakage at master cylinder?

Never had the pleasure of brake failure but have experienced low erratic pedal in a vehicle with leaky slave cylinders allowing air in, not applicable here but calipers can leak again something I've never had.

SO I'm thinking overheated brakes with old fluid if water contaminated can lower boiling point which in turn if the fluid boils then it becomes a gas and being compressible would mean no or greatly reduced pressure in the lines.

Or

Master cylinder failure, could be worn internal bore, seal failure or faulty valving


How's the fluid level been? has it needed regular top ups? Gradual level drop over long time is normal as the pads wear and the pistons adjust

[Surferdude]

I've cooked my brakes many times. It's a hazard of rally cars on long downhill stages.
But the pedal has never gone all the way to the floor.

I'm puzzled about this problem. With split system brakes, Surely if the pedal went all the way to the floor but pumped up a bit the issue would be in the master cylinder.

Or is it too early in the morning for my brain to be working properly?

[tw2005]

I've cooked my brakes many times. It's a hazard of rally cars on long downhill stages.
But the pedal has never gone all the way to the floor.

I'm puzzled about this problem. With split system brakes, Surely if the pedal went all the way to the floor but pumped up a bit the issue would be in the master cylinder.

Or is it too early in the morning for my brain to be working properly?

So long as sun is shining you should be safe. I'd go with master as most likely place to start with .

[beerman]

You haven't lived until you have all 4 pads smoking.....

From memory pedal nearly went to the floor from memory....

Is there a chance of air in the brake fluid after the fluid change?

[tw2005]

You haven't lived until you have all 4 pads smoking.....

From memory pedal nearly went to the floor from memory....

Is there a chance of air in the brake fluid after the fluid change?

Looks like you are having a memory overrun

I guess we may learn more when they reply to my line of questioning

[Surferdude]

You haven't lived until you have all 4 pads smoking.....

From memory pedal nearly went to the floor from memory....

Is there a chance of air in the brake fluid after the fluid change?

Looks like you are having a memory overrun

I guess we may learn more when they reply to my line of questioning

My take from the OP was that all then things done to the brakes were in response to the original failure.

[tw2005]

You haven't lived until you have all 4 pads smoking.....

From memory pedal nearly went to the floor from memory....

Is there a chance of air in the brake fluid after the fluid change?

Looks like you are having a memory overrun

I guess we may learn more when they reply to my line of questioning

My take from the OP was that all then things done to the brakes were in response to the original failure.

Implied, just nice to confirm the order of things it 

[Dazzler]

Hi, I was under the impression this was extremely unlikely to happen in normal driving with a modern vehicle due to there being a split system. One for each diagonally opposing set of wheels?

I did a google for brake failure in Hyundai i30 and it bought me straight back to our site! Seems to be extremely rare with i30's as I suspected.

There was this one (split hose during MOT)

COMPLETE Brake failure

and this, not actually a failure but a recall related to the brake light switch.

i30 FD and FDe recalling for brake valve problem.

this one is the closest I could find but no conclusion - I wonder if I can contact Katy to find out what happened.

Brakes failure

EDIT: I'm sending Katy an email to see what ended up happening. Hoping she hasn't changed her email address or died in a horrible accident related to brake failure! 

[Surferdude]

Just re-read the first page of Katy's issue.
I still feel it was ABS which would suggest she WAS on a slippery surface like ice. Which is quite possible. She said she has experienced ice before in her long driving history but I reckon it was her first time on ice with ABS.

[nzenigma]

I still feel it was ABS which would suggest she WAS on a slippery surface like ice. Which is quite possible. She said she has experienced ice before in her long driving history but I reckon it was her first time on ice with ABS.

Like yo'l, Im at a loss to explain how a sealed system can go pedal to the floor, pump up and then show no signs of fluid loss or air in.

So ABS on ice  or oil would seem reasonable to me too. 
The brain doesn't necessarily rationalise these unexpected moments.
For instance, Main Roads 'upgraded'    the road out of Samford Valley. When it is wet, we now have numerous cars coming unstuck on one badly designed bend ( downhill with the wrong cambre) .
A young female driver I know, rolled and totalled her FD there recently. She swears that the Hyundai's steering locked solid.

[Jkredcliffe]

We changed the fluid after and car had only been running 15 minutes. I wasn't working the brakes as had kids in the car so don't tend to rally around lol. Just worried will happen again and no error codes either

[Jkredcliffe]

Also no ice or oil. Was like it for a few miles until we could pull over. Other half said pumping brakes helped slightly. Completely baffled now only make short journeys as usually on motorway alot

[Dazzler]

EDIT: I'm sending Katy an email to see what ended up happening. Hoping she hasn't changed her email address or died in a horrible accident related to brake failure! 

Email returned. Hopefully just changed their email address. 

[noels_hobby]

once had similar experience with a previous car (mitsi colt) driving normally came up to the lights foot straight to the floor. 10 min later every thing normal.
i didn't know this till later but brake fluid like diesel adsorbs moisture, the fluid had been changed and the mechanic used an open bottle then topped with a new bottle. we suspect the open bottle was contaminated with moisture that turned to steam at the calliper which compresses at a different rate to the fluid
to be sure new unopened fluid and bleed each cylinder make sure the correct dot fluid is used 

[Dazzler]

  for that.

[Weenan]

Hi There, did you get resolution for this problem ? as my car has done exactly the same, yesterday I was approaching a roundabout, and nearly rear ended the car in front, just like yours, I pumped the pedal and it worked again, but failed a little further down the road.
I have had a mechanic look at it, no warnings were showing on the mechanics computer when it was plugged in, but he suggested that the abs module might be faulty.

[piotec52]

BEWARE the most neglected vehicle safety maintenance issue, Brake Fluid Replacement! Even the best Dot 4, low moisture absorption fluids must be replaced every 2 years, max. Most vehicle manufacturers specify Brake Fluid Replacement periods, but Hyundai appears to be in the dark on this topic. My 2016 Santa Fe and 2017 i30 Handbooks only require "Inspect for fluid level" info, with no replacement periods whatsoever! The dealer never replaced my brake fluid, even though it was 32 months old!

I am qualified and experienced in Mechanical Engineering and design, vehicle brake fluids and servicing, and wholesaled USA Dow Corning and GE (non-hygroscopic) silicone brake fluids while they were available.

During my brake fluids experience I did extensive vapor lock testing (with Castrol and other testers) with various age brake fluid samples, and was alarmed that many samples only a little over 12 months old were already "boiling" and producing vapor lock at less than 120 deg C. Not much better than pure water, at 100 deg C. New fluid should exceed 230 deg C.

Most mechanics, workshops, and even some vehicle manufacturers are from my experience, dangerously undereducated!

[Dazzler]

  piotec52 ,

Thanks for that insight. 

Be interesting to know what the other manufacturers do.

[CraigB]

BEWARE the most neglected vehicle safety maintenance issue, Brake Fluid Replacement! Even the best Dot 4, low moisture absorption fluids must be replaced every 2 years, max.

It's generally specified on the brake fluid containers, DOT 3 and 4 has always been two year replacement

[Surferdude]

I'm sure my FD service schedule said replacement at 30,000 (2 years).

[Dazzler]

I'm sure my FD service schedule said replacement at 30,000 (2 years).

Come to think of it I think the brake fluid was replaced at 2 years in Trish's CW which was a pain because she had only done like 12,000 or something after 2 years! I know it's a time thing not distance..

[mickd]

G'Day ,

 2 years seems to be generally recommended.
Sometimes the type that doesn't absorb water sends the water to the lowest piont .
Some BMW bikes were rusting out the abs sensor due to water collecting there.

[tw2005]

BEWARE the most neglected vehicle safety maintenance issue, Brake Fluid Replacement! Even the best Dot 4, low moisture absorption fluids must be replaced every 2 years, max. Most vehicle manufacturers specify Brake Fluid Replacement periods, but Hyundai appears to be in the dark on this topic. My 2016 Santa Fe and 2017 i30 Handbooks only require "Inspect for fluid level" info, with no replacement periods whatsoever! The dealer never replaced my brake fluid, even though it was 32 months old!

I am qualified and experienced in Mechanical Engineering and design, vehicle brake fluids and servicing, and wholesaled USA Dow Corning and GE (non-hygroscopic) silicone brake fluids while they were available.

During my brake fluids experience I did extensive vapor lock testing (with Castrol and other testers) with various age brake fluid samples, and was alarmed that many samples only a little over 12 months old were already "boiling" and producing vapor lock at less than 120 deg C. Not much better than pure water, at 100 deg C. New fluid should exceed 230 deg C.

Most mechanics, workshops, and even some vehicle manufacturers are from my experience, dangerously undereducated!

amen 

But wait, there's more. you also have those dealers who charge for a fluid change and don't do it! Hopefully the minority but I have caught one.

[eye30]

My dealer changes the fluid every 2 years on my 2 cars duri g warranty period of 5 years.

Now out of warranty at last service they checked it on some gismo and declared ok but will change next service so 3 years max.

[nzenigma]

they checked it on some gismo and declared ok

you also have those dealers who charge for a fluid change and don't do it! Hopefully the minority but I have caught one.

 Gerard has a gismo 


 

[tw2005]

they checked it on some gismo and declared ok

you also have those dealers who charge for a fluid change and don't do it! Hopefully the minority but I have caught one.

 Gerard has a gismo 


 

Yeah, eyes  It was a case of the fluid being the same colour and dust being on the master cylinder cap not disturbed. It was a beautiful moment after they argued they had done it up util the point I pointed this fact out

[nzenigma]

they checked it on some gismo and declared ok

you also have those dealers who charge for a fluid change and don't do it! Hopefully the minority but I have caught one.

 Gerard has a gismo 


 

Yeah, eyes  It was a case of the fluid being the same colour and dust being on the master cylinder cap not disturbed. It was a beautiful moment after they argued they had done it up util the point I pointed this fact out

 

Eyes and a brain, how novel. 

[mickd]

they checked it on some gismo and declared ok

you also have those dealers who charge for a fluid change and don't do it! Hopefully the minority but I have caught one.

 Gerard has a gismo 


 

Yeah, eyes  It was a case of the fluid being the same colour and dust being on the master cylinder cap not disturbed. It was a beautiful moment after they argued they had done it up util the point I pointed this fact out