Brake Wizzard?

[fred130111]

My friend is having some issues with his brakes on his Celica, I know this is an MR2 forum and I have an MR2 but not come accross an issue like this before.

Its a 3sge and I have had issues on my MR2 before but not like this....

So if your in 5th gear or any gear at High Revs you start to get a strange smell after about 10mins of driving ( Smells Like Rubber ) cant work out if its coming from behind the dash or coming from the exhaust (Its very strong burning smell ) and around 10 seconds later the brakes pretty much have no effect. The pedal goes to the floor with no resistance and there is no real braking at all.

I have read that it could be the master cylinder playing up however it makes me think its vaccume issue as it only happens between 5 - 6k revs. Low speed / low revs it seems to work fine, disks and pads are all new. Only other thing i could think was it may have air in the system but my experiance with this is its not normally intermittent.

Cheers in advanced guys, quite worrying!

[Nic]

Are you sure it's not the clutch slipping that's causing the smell? A clutch will first start to slip when accelerating in a higher gear, when it's under the most load. To test it try driving at say 30mph put it in 5th then accelerate, if the clutch is slipping the engine revs will rise faster than the car accelerates; if it is slipping don't repeat this as it'll get very hot very quickly.

[fred130111]

I will test tonight, but im pretty sure the clutch isnt slipping although it does feel a bit gutless when in 5th... previously when i have had this issue the car revs up and the clutch does nothing and will then grip but this doesnt seem to be happening with this...

Any ideas with regards to the brakes?

[Draven]

I will test tonight, but im pretty sure the clutch isnt slipping although it does feel a bit gutless when in 5th... previously when i have had this issue the car revs up and the clutch does nothing and will then grip but this doesnt seem to be happening with this...

Any ideas with regards to the brakes?

Have a professional look at the brakes.. I would not drive the car until they have.. I'd say possible boiled fluid, leak or master cylinder the braking system is quite simple so it should be quite easy to pin point.

The way to test for clutch slip is to choc or handbrake the car put it in say 3rd then lift the clutch and see if the car stalls and when it stalls.

The gearbox could have worn in 5th this is always a possibilty.


As said i'd get a professional to have a look.

[fred130111]

Yeah I will do thanks for the advise, It is a very strange situation, normally I can work out what the problem is and sort it but theres not much info out there for these type of symptoms!

[Keri-WMS]

I wonder if there's a sticky caliper or pad - it'll get very hot, and can then boil the fluid in that one caliper = soft pedal, funny smell and no brakes.

[Draven]

+ This.

[fred130111]

Hmmm yeah that would make sense but the weird thing is you can pump it back up or it will restore to normal after about 30 seconds!

There are no leaks, the flud does not go down at all...

The only thing I have found online is people saying the Master Cylinder can let flud past the seals and lose pressure.