Brake problem!

[T9 man]

Last night on the way to a call out, my brake pedal started to feel a little funny, i.e. my pedal had to be pushed down a little further than usual before I could feel a firm bite. Normally I just touch the pedal and I can feel the bite straight away, but have to push down a couple of inches now before anything starts to happen.

If I pump the pedal a little the firm feeling that I am use too, comes back!

Some Background! The front discs, calipers and pads are about 6 months old with steel braided hoses. The total mileage covered in this time is about 9K and I have done one track day!
The rear pads were also replaced at the same time, and the brake fluid was also replaced at the time of the new disc & caliper installation with Halfords own Dot 5.1 brake fluid.

Any ideas?

 

[HDi fun]

I'd have it straight down to a dealer or independent specialist for inspection. It's probably not at all serious but I am extremely funny and fussy about brakes and steering.

 

[T9 man]

I am exactly the same HDi It will have to be Monday morning now as I don't feel confident enough about Kwik-Fit to take my baby there for a check up tomorrow!

 

[pgarner]

whats wrong with quick fit ?

were you hard on the brakes at he track day ? you may have boiled a bit of fluid off

was it the 1st press of the pedal ? i find that the 1st couple of presses nothing much wants to happen - dont mean that i have no brakes just i feel the need to brake harder for it to stop, same as your feeling most likely.

 

[HDi fun]

I agree - stay well away from Kwik Fit unless you have access to a known good branch. I have yet to find one of those.

 

[Prince]

Sounds like the master cylinder and servo are playing up.

 

[HDi fun]

was it the 1st press of the pedal ? i find that the 1st couple of presses nothing much wants to happen - dont mean that i have no brakes just i feel the need to brake harder for it to stop, same as your feeling most likely.

If it had been this way all along then I'd agree, possibly just a characteristic of the car's braking system (though not one I'd welcome).

The fact that the braking performance and behaviour has changed is more than reason enough for me to get it professionally examined.

 

[T9 man]

whats wrong with quick fit ?

were you hard on the brakes at he track day ? you may have boiled a bit of fluid off

was it the 1st press of the pedal ? i find that the 1st couple of presses nothing much wants to happen - dont mean that i have no brakes just i feel the need to brake harder for it to stop, same as your feeling most likely.

The 1st press of the pedal was always firm but now it needs to go down a couple of inches! my alarm bells started ringing :sad2:

 

[T9 man]

Sounds like the master cylinder and servo are playing up.

Marvellous! the cars now got plenty of go but is reluctant to whoa when you want it too

 

[T9 man]

I agree - stay well away from Kwik Fit unless you have access to a known good branch. I have yet to find one of those.

Which I do not, neither do I know of anyone who could actually recommend a good branch to me :sad2:

 

[HDi fun]

Marvellous! the cars now got plenty of go but is reluctant to whoa when you want it too

It might be something as simple as a brake caliper starting to sieze up.

But it still needs professional examination - a sudden change in braking performance must be looked at.

 

[T9 man]

It might be something as simple as a brake caliper starting to sieze up.

But it still needs professional examination - a sudden change in braking performance must be looked at.

Hopefully that will be so! cheers HDi

 

[pgarner]

If it had been this way all along then I'd agree, possibly just a characteristic of the car's braking system (though not one I'd welcome).

The fact that the braking performance and behaviour has changed is more than reason enough for me to get it professionally examined.

as he has had a bigger brake upgrade then he may have well had pads fitted that have higher operating temp, and as such require some more heat in the pads.
since i swapped to the ds2500 pads - classed as racing pads - i find that the 1st press doesnt do much, but as im normally braking within 50 meters of starting by the time im using the brakes properly they are solid.

this doesnt seem to be the case with T9 however as he says the pedal is now softer, whereas it was firm before.

mines feels the same press wise, slight sponge for the 1st maybe half inch then rock solid, on the 1st or 100th brake since the car started. its only the way the car "woahs" on the 1st or 2nd press.

id hope it wasnt a calliper seizing as they are pretty new but check out is required. even if they cant find a leak or anything really from it could benifit for a bleed.

thinking of that is the clutch ran off the same reservoir as the brakes ? if so did they flush new fluid through the clutch as well

 

[T9 man]

as he has had a bigger brake upgrade then he may have well had pads fitted that have higher operating temp, and as such require some more heat in the pads.
since i swapped to the ds2500 pads - classed as racing pads - i find that the 1st press doesnt do much, but as im normally braking within 50 meters of starting by the time im using the brakes properly they are solid.

this doesnt seem to be the case with T9 however as he says the pedal is now softer, whereas it was firm before.

mines feels the same press wise, slight sponge for the 1st maybe half inch then rock solid, on the 1st or 100th brake since the car started. its only the way the car "woahs" on the 1st or 2nd press.

id hope it wasnt a calliper seizing as they are pretty new but check out is required. even if they cant find a leak or anything really from it could benifit for a bleed.

thinking of that is the clutch ran off the same reservoir as the brakes ? if so did they flush new fluid through the clutch as well

Thanks PG, I will print this off and pass it onto the garage tomorrow.

 

[pgarner]

sorry missed out a maybe there. sound be

could maybe benefit from a bleed.
i know the track days are hard on the brakes and not sure if the halfords would be up to it as i must have boiled some off on an enthusiastic drive to edinburgh. very weird feeling when the pedal ended up spongy

 

[HDi fun]

Brake pedal feel should never be 'spongy'.

It should be firm and offer immediate 'bite'.

It's good technique to do a moving brake test when you drive off when the car has been parked over night.

But any change in pedal feel or braking force must be investigated.

 

[Prince]

It might be something as simple as a brake caliper starting to sieze up.

But it still needs professional examination - a sudden change in braking performance must be looked at.

Doesn't a seizing caliper make the car pull to one side under braking?

 

[HDi fun]

Doesn't a seizing caliper make the car pull to one side under braking?

Not if it's a rear one that's just sticking a bit.

 

[Prince]

Not if it's a rear one that's just sticking a bit.

So I'd be right in thinking a front caliper that's seizing would cause the car to pull to one side under braking?

 

[herb]

just to pick up on what prince suggested. your calipers are 6 pots now arent they t9?? if so is the servo/master cylinder up to the job??
are other saab owners using the same setup without issues??

 

[T9 man]

just to pick up on what prince suggested. your calipers are 6 pots now arent they t9?? if so is the servo/master cylinder up to the job??
are other saab owners using the same setup without issues??

Hi Herb, the Beast is booked in for 2 this afternoon so all will be revealed soon enough. The MapTun race car has the identical setup with the same factory servo and has been running for over a year on the same model car now! I am the only Saab guy who currently has this setup outside of the racing team

 

[herb]

Hi Herb, the Beast is booked in for 2 this afternoon so all will be revealed soon enough. The MapTun race car has the identical setup with the same factory servo and has been running for over a year on the same model car now! I am the only Saab guy who currently has this setup outside of the racing team

ok mate keeps us informed:bigsmile:
but my money is on pg's boiled fluid suggestion

 

[T9 man]

Hi fellas i'm back, and the brake fault was! drum roll please! The fluid!

It was well and truly fried with no life in it at all :amazed: the mechanic, oops
sorry! :embarrest: The Master Technician!! was surprised that I still had any feel in the pedal at all. All the battered rubbish has now been flushed through with some Dot 5.1 and now it stops on a sixpence again!

Many thanks for all the help guys! and a Gold Star goes to PG

 

[HDi fun]

Next track day perhaps get it drained and replaced directly afterwards.

 

[T9 man]

Next track day perhaps get it drained and replaced directly afterwards.

Good thinking Hdi I'm actually racing my baby this Sunday at the new Snetterton track in Norfolk, so I will book a brake fluid change for first thing Monday morning

 

[pgarner]

 

[herb]

Glad it was something simple for you mate!

 

[MasterAuron]

Next track day perhaps get it drained and replaced directly afterwards.

Not necessary, just use better brake fluid!

 

[T9 man]

Glad it was something simple for you mate!

Cheers Herb, funny thing though? this is the first real fault that I have ever had on the baby, were I got change from £50 to sort it out :amazed::amazed::amazed:

This never happens! Faults for T9 must always be a Ton plus usually!

 

[HDi fun]

Not necessary, just use better brake fluid!

What would you recommend then?

Are there brake fluids which can stand a few hours of savage track usage and still remain stable in daily operation?

 

[T9 man]

Not necessary, just use better brake fluid!

Your probably right MA, Halfords Dot 5.1!!! what was I thinking? or not, as the case would be!

 

[MasterAuron]

Of course especially when your brakes are good at disappating heat like I'd imagine T9's are. Something like ATE Super Blue would suffice, if you keep boiling a high performance fluid even on track I'd say something else needs a look at. You can get better though like Endless RF-650 for example.

Do F1 cars change their brake fluid half way through a race lol.

 

[T9 man]

What would you recommend then?

Are there brake fluids which can stand a few hours of savage track usage and still remain stable in daily operation?

Good question! why did'nt I think of that? :embarrest:

 

[T9 man]

Of course especially when your brakes are good at disappating heat like I'd imagine T9's are. Something like ATE Super Blue would suffice, if you keep boiling a high performance fluid even on track I'd say something else needs a look at. You can get better though like Endless RF-650 for example.

Do F1 cars change their brake fluid half way through a race lol.

Marvellous! thanks for the valued info MA

 

[HDi fun]

Copper grease will keep the temperatures down nicely if you apply it directly to the discs.

 

[MasterAuron]

Copper grease will keep the temperatures down nicely if you apply it directly to the discs.

You can bet your bottom dollar someone, somewhere will have done this!

 

[HDi fun]

You can bet your bottom dollar someone, somewhere will have done this!

Yes, sadly I think you're probably correct.

One thing that is worth doing is thoroughly cleaning off the mating surfaces of the hubs and the insides of the rims before applying a very fine layer of copper grease to these parts when remounting the wheels. This maximises heat transference away from the brakes themselves.

An alloy wheel is a very effective heatsink for the brakes on any car - it transfers heat from the hubs and acts as a large radiator cooled by airflow.

 

[T9 man]

Yes, sadly I think you're probably correct.

One thing that is worth doing is thoroughly cleaning off the mating surfaces of the hubs and the insides of the rims before applying a very fine layer of copper grease to these parts when remounting the wheels. This maximises heat transference away from the brakes themselves.

An alloy wheel is a very effective heatsink for the brakes on any car - it transfers heat from the hubs and acts as a large radiator cooled by airflow.

Cheers HDi, I will give the garage a call in the morning and ask them about the copper grease!

 

[HDi fun]

Do F1 cars change their brake fluid half way through a race lol.

No, but they don't drive the cars home after the race and then expect the brakes to behave perfectly for another 10,000+ miles of general road usage.

 

[jarrus]

Seriously dude, your pockets must be deep to keep taking it back there, then again they have to keep you sweet because of the business you are giving them.