Fancy doing brake tests !
Discussion
Hi good morning gentlmen.
Bit of a strange request in know but it might save lives.
As we don't have ABS braking I make it a point to test the brakes as in emergency stops to the point the front wheels will lock up.
I do this a number of times to get used to the rough position and pressure required on the pedal when lock up occurs,,
Regardless of what type of brakes fitted my car will always lock the o/s front wheel first.
Is this a problem with my car ( probably) but I was just wondering what other drivers experience of this type of test is,,
Has anyone done controlled emergency testing on as smooth and level a piece of Tarmac they can find.
It's important to slow the car from high speed so the brakes are really working, then when your down to say 30 mph and the car is heavily loaded up on the front wheels actually push the pedal harder so to momentarily lock the wheels,
It's needless to say you need to be confident in your reactions to do this as you'll want to release the pedal instantly lock up occurs.
If anyone has done such tests or would like to then please do it in a controlled manor but what were your results.
I'd like to know if others have a similar issue.
I'd never have known I get this lock up on the o/s front wheel if I'd not provoked it with extreme braking.
I'm mindful of the danger of doing this so if you try it's very important to get as level a road as possible and away from other road users.
It's a test we should all do really as we are the ABS system on the car!
What's your results, I'm only interested in lock up point and if both wheels lock or you get one wheel locking first.
There's a number of reasons why one wheel may lock before the other but I'd hopefully see a trend.
Ignore this if your not comfortable with it,, BUT you may need to know this information one day so it's valuable for your own driving brain.
Cheers Alun.
Bit of a strange request in know but it might save lives.
As we don't have ABS braking I make it a point to test the brakes as in emergency stops to the point the front wheels will lock up.
I do this a number of times to get used to the rough position and pressure required on the pedal when lock up occurs,,
Regardless of what type of brakes fitted my car will always lock the o/s front wheel first.
Is this a problem with my car ( probably) but I was just wondering what other drivers experience of this type of test is,,
Has anyone done controlled emergency testing on as smooth and level a piece of Tarmac they can find.
It's important to slow the car from high speed so the brakes are really working, then when your down to say 30 mph and the car is heavily loaded up on the front wheels actually push the pedal harder so to momentarily lock the wheels,
It's needless to say you need to be confident in your reactions to do this as you'll want to release the pedal instantly lock up occurs.
If anyone has done such tests or would like to then please do it in a controlled manor but what were your results.
I'd like to know if others have a similar issue.
I'd never have known I get this lock up on the o/s front wheel if I'd not provoked it with extreme braking.
I'm mindful of the danger of doing this so if you try it's very important to get as level a road as possible and away from other road users.
It's a test we should all do really as we are the ABS system on the car!
What's your results, I'm only interested in lock up point and if both wheels lock or you get one wheel locking first.
There's a number of reasons why one wheel may lock before the other but I'd hopefully see a trend.
Ignore this if your not comfortable with it,, BUT you may need to know this information one day so it's valuable for your own driving brain.
Cheers Alun.
Danattheopticians said:
I may sound dumb or like I'm missing the point when I ask this next question. But shouldn't the majority of the braking force be to the rear wheels in a RWD car? If not why not, I thought that would be safer?
it would spin round if most of the braking was at the rear I do this every trip in my old Ford Ranger pickup (or in any other vehicle while carrying a biggish load) as the braking is very dependant on weight distribution. The pickup is like most vans and has load sensors which alter the braking sensitivity according to load distribution but this never works 100% the same every time so it is good to have an idea how your vehicle is going to handle before you get too far on your journey.
I don't set out to do it in a 'normal'car, but usually find myself doing it as a matter of instinct now. It's a bit like shaking yourself down , rolling your shoulders etc before setting out for a run, just getting a feel for your body.
I don't set out to do it in a 'normal'car, but usually find myself doing it as a matter of instinct now. It's a bit like shaking yourself down , rolling your shoulders etc before setting out for a run, just getting a feel for your body.
Danattheopticians said:
I may sound dumb or like I'm missing the point when I ask this next question. But shouldn't the majority of the braking force be to the rear wheels in a RWD car? If not why not, I thought that would be safer?
Higher brake force on any car fwd or rwd will always occur on the front brakes due to weight transfer, there is a lot less weight over the rear wheels due to this, so if the higher force was applied to the rears, the tyres would simply lock up too easily and little actual slowing down would be the result.
over_the_hill said:
Where is the brake master cylinder (I realise I should know this)
Somewhere near the brake pedal at a guess 
I assume you don't check your fluid levels too often?
over_the_hill said:
as I would naively expect the wheel nearest to the cylinder to get slightly more pressure in the brake line and thus more stopping effect.
Pressure is a great equalizer!phillpot said:
over_the_hill said:
Where is the brake master cylinder (I realise I should know this)
Somewhere near the brake pedal at a guess I assume you don't check your fluid levels too often?
over_the_hill said:
as I would naively expect the wheel nearest to the cylinder to get slightly more pressure in the brake line and thus more stopping effect.
Pressure is a great equalizer!Although the top up reservoir is in the OS wing this is TVR so it doesn't necessarily mean the actual cylinder is close by and although you would expect the cylinder to be close to the pedal some sort of Heath-Robinson arrangement wouldn't surprise me.
Not locking the NSF wheel will probably be down to a number of factors.
Camber of the road transferring weight to the NS could be one such factor as could be the NS typically being a dirtier part of the road and therefore brakes getting more dirty on that side having an adverse effect on brake performance.
Camber of the road transferring weight to the NS could be one such factor as could be the NS typically being a dirtier part of the road and therefore brakes getting more dirty on that side having an adverse effect on brake performance.
vanordinaire said:
I do this every trip in my old Ford Ranger pickup (or in any other vehicle while carrying a biggish load) as the braking is very dependant on weight distribution. The pickup is like most vans and has load sensors which alter the braking sensitivity according to load distribution but this never works 100% the same every time so it is good to have an idea how your vehicle is going to handle before you get too far on your journey.
I don't set out to do it in a 'normal'car, but usually find myself doing it as a matter of instinct now. It's a bit like shaking yourself down , rolling your shoulders etc before setting out for a run, just getting a feel for your body.
Thanks for that positive response, I'm glad I'm not the only one doing this sort of thing. I don't set out to do it in a 'normal'car, but usually find myself doing it as a matter of instinct now. It's a bit like shaking yourself down , rolling your shoulders etc before setting out for a run, just getting a feel for your body.
With the Tvr Its a case of doing any work in that area then requires some checks rather than I do this on a weekly basis.
It's just to know where you stand, I take a mental picure of all the physics involved then add it to my memory bank,, it's clear you then understand what the cars capable of in a similar circumstance,,
That knowledge will bounce straight to the front of your memory in an emergency,, it will hopefully keep you focused on the job of stopping at that moment.
Panic is a human response to a life threatening event, locking the wheels when you need them gripping can Lead to disaster so knowing what to do is vital.
You have to experience this sensation to accept it and deal with it. If it comes as a suprise at a critical moment and you hesitate,,
Back to the question in hand,
I'd love to conduct a controlled test and just see what happens with wheels locking and which one or both lock first using a number of our cars,,
Mine has an issue with the left front brake,,
I was just considering if there's a natural bias as otherwise your locking the left and as the road is generally better grip in the middle it would make sense to have more braking on the right,, but that does seem nonsense as surely the car would pull to the right!
But my car even with a problem with the left front brake doesn't lurch to the right drastically at all?
That's probably why I've considered this.
I also wondered if the longer brake line to the left front would offer less pressure but that too seems like I'm grasping at straws.
What I will say is test your brakes.
I will use the brake tester at my mates garage to ascertain my brake pressure on each wheel as mines incorrect regardless of what it should be,
Let's stay on brake tests.
Do this one day a number of times on the exact same piece of Tarmac on a smooth country lane or a private road or even better at a race circuit and report your findings,,
I'd be very interested in the results.
But please don't do this if this thread makes you feel uncomfortable and poses a danger to anyone including yourself.
Thanks Al
Let's stay on brake tests.
Do this one day a number of times on the exact same piece of Tarmac on a smooth country lane or a private road or even better at a race circuit and report your findings,,
I'd be very interested in the results.
But please don't do this if this thread makes you feel uncomfortable and poses a danger to anyone including yourself.
Thanks Al
ClassiChimi said:
I will use the brake tester at my mates garage to ascertain my brake pressure on each wheel as mines incorrect regardless of what it should be,
Let's stay on brake tests.
Do this one day a number of times on the exact same piece of Tarmac on a smooth country lane or a private road or even better at a race circuit and report your findings,,
I'd be very interested in the results.
But please don't do this if this thread makes you feel uncomfortable and poses a danger to anyone including yourself.
Thanks Al
Hi AlLet's stay on brake tests.
Do this one day a number of times on the exact same piece of Tarmac on a smooth country lane or a private road or even better at a race circuit and report your findings,,
I'd be very interested in the results.
But please don't do this if this thread makes you feel uncomfortable and poses a danger to anyone including yourself.
Thanks Al
Have you thought about corner weighting, I assume your Protechs are adjustable platform and if not set up correctly, front/rear, off side/near side, the weight of the car will be distributed unevenly over all four corners and hence the corner with the least amount of laden weight will lock up prior to others.
Corner weighting should be carried out with yourself or something weighing a similar weight to yourself in the drivers seat presuming you predominantly drive solo
Cheers BA
Hi Ash, yeah I know how to use the weights but havnt had my car on them yet. It's a very good point and one we should always remember, I have dropped the ride height on the front left to induce more weight and it worked to a degree.
I have a brake problem that's more the issue than a ride height indifference but it's just an interesting question to answer as I had similar lock up on the old discs and calipers.
I have a brake problem that's more the issue than a ride height indifference but it's just an interesting question to answer as I had similar lock up on the old discs and calipers.
Gassing Station | Chimaera | Top of Page | What's New | My Stuff