Volvo 480 Club Europe

just had a race with a calibra 2.0L (it lives next door) and
found that the brakes didn't stun me (if you know what I mean )
could ya please help me decide

1- upgrade to vented turbo brake discs and calipers (cheapish option I
know but I'm kinda skint)

2- blow all the dosh prime stoppers with grooves etc (its the two litre
and as such seems limited in engine tuning possibilities I'll
never have 200 bhp in my 480

will the turbo brakes be a vast improvement over the solid discs I have now?

Nah, talk to red-dot and get some 6 grooved discs and some of their fast road pads. excellent stopping power with them babies.

JayTee wrote:
will the turbo brakes be a vast improvement over the solid discs I have now?

I'd say not - not for short/one off braking experiences. You'd see an improvement if you did a 3 mile race round twisty roads or round a load of roundabouts (eh, JohnTurbo, MatBat and Holmes!?! ) - i.e. when you're on and off the brakes a load - I'd expect the solids to fade quicker than the vented, but other than that there won't be much difference.

i agree with what dragon said but even with solid discs surely you could lock the wheels (or engage the abs) once or twice before they heat up? The vented discs do the same but will heat up much much slower.

In actual fact, its not the heat of the discs/pads that casues fade per se.

When the brakes on a road car fade, 99% of the time it is due to the brake fluid boiling, and minute (so small you probably wouldn't see them when bleeding) air pockets forming as a result.
This is due to the discs/pads being unable to disippate the heat to the atmosphere, due to insufficient cooling. The heat has to go somewhere, so it goes into the fluid.
By upgrading to vented discs, you are enabling the discs to dissipate the heat to atmosphere more easily, raising the point at which the heat starts to transfer to the fluid.

AS above, the fade is caused by boiling the fluid, therefore, once you have induced fade in the brakes, you lower the threshold at which the fluid can boil the next time (this also gets worse the older the fluid, due to it being very hygroscopic (sp?) - it absorbs water) so if you cause fade in the brakes you shoudl really at least bleed the brakes, if not flush the fluid through.
You should flush the fluid every second year as a matter of course anyway
(i'm one to talk, did mine last summer and the stuff that came out was brown )

Jaytee, if your brakes don't feel amazing, do a full fluid flush first. be warned though - I am reliably informed that the 480 braking systems contain components that are not designed to handle DOT 5.1 fluid - eventually it will go through the caliper and/or master cylinder seals. Use a good quality DOT 4 fluid instead.

If after doing a flush they should be much MUCH better. Volvo brakes are renowned for being good, and flushing my fluid made one hell of a difference.

Another thing to watch out for is the bolts that the front floating calipers slide on. These can seize in place, meaning the pads may only contact on one side of the disc, or potentially (if you fluid is really shite!) not at all on the affected caliper. Just had to unseize one of mine (again) and i unseized and greased them all when i fiitted new pads last summer.

Hope that helps.

Chris

The calipers will fit, just make sure the offset of the wheels is enough to clear the calipers, there was a thread about this the other month.

I have a set of turbo calipers sat in my kitchen, for another mad part fo the project, measured the piston, and now i am saving for a new pedal box, and will be removing the servo assist, and abs.

In extreme brake situations you can buy a brake fluid recirculator, but on a 480 it would be overkill, this stops the same fluid being in the caliper the whole time, and therefore less prone to boiling.

clicky!

great page this, take time to read all of it, and specifically myths 3+4

chris

Call me paranoid, but i usually change the brake fluid with every change of pads.

Its very scary when the pedal goes straight to the floor, managed this a few times in the puma, once on a track day, its amazing how it helps your lap times

For most people, me NOT included- every change of pads would be less often than every second year!
I think I'm going to change mine again this year too - pads are coming up for changing again... might get 13k out of them this time!!

Interesting chriss and now that i've read that i'm gonna change my brake fluid soon. But boiling brake fluid doens't explain smoking brakes (like there's something burning) after a few hard stops. A lot of noise coming from hot brakes that hardly work simply means that the brakes get to hot. But I don't know if that happened in JayTee's case.

Oh yeah, i've cooked the pads before now too - had them visibly smoking. However, the fluid will also have boiled at the same time, and it is this that will have caused most of the fade i felt at the time......
In fact i cooked the pads on the 440 i owned, and i had had new fluid put in about 3 months previously and they did not fade........IIRC...long time ago.

Normally a set of pads for me at least every 8 months, worst is a set of pads in two months, but that was 2 track days and some very hard road driving.

Dragon/Jamo

I've just orderded some calipers (turbo ones) I haven't chosen discs yet
however I have more questions---

1- will the turbo calipers be a straight swop (using the same fittings as the calipers I have on the car ?
2- what bits should I have on standby (I'm gonna try to do it myself
and would like to have all the bits ready just in case anything goes wrong)

JayTee wrote:Dragon/Jamo

I've just orderded some calipers (turbo ones) I haven't chosen discs yet
however I have more questions---

1- will the turbo calipers be a straight swop (using the same fittings as the calipers I have on the car ?

I believe this to be the case, yes.

JayTee wrote: 2- what bits should I have on standby (I'm gonna try to do it myself
and would like to have all the bits ready just in case anything goes wrong)

Other than a spare set of retaining bolts, and a tin of grease handy, I can't think there's too much that could go wrong and need spares for?

I'm sure others will correct me or add to the list

chris1roll wrote:clicky!

great page this, take time to read all of it, and specifically myths 3+4

chris

Now, call me picky, but how do we know that site has corrrect info?

I ask because the only time I've had a "moment" with brakes was in JohnTurbo's car, and what happened was the brake pedal went VERY soft
indeed - in fact it went full travel without much of a braking effect. So according to that site, the fluid boiled. But that site says this is a gradual effect. But when I was in JTs car this was a ver very sudden effect - i.e. I had full braking on the last roundabout we flew around, brakes were very good indeed, then less than 300 yards up the road, I came to slow for another roundabout, and I had virtually NO braking at all, with the pedal going a long way from the start - there was NO warning of any kind at all.

When we stopped the car, we got out to investigate, and there was a brake burn smell, but not too bad. A few mins of sitting later and the brakes were totally back to normal.

So my one and only experience with brakes does not fit correctly with either of that site's only options.

You'd see an improvement if you did a 3 mile race round twisty roads or round a load of roundabouts (eh, JohnTurbo, MatBat and Holmes!?! ) -

heh, I got pictures from that day I have brembo vented discs that will get fitted very soon.

when I was in JTs car this was a ver very sudden effect - i.e. I had full braking on the last roundabout we flew around, brakes were very good indeed, then less than 300 yards up the road, I came to slow for another roundabout, and I had virtually NO braking at all, with the pedal going a long way from the start - there was NO warning of any kind at all.

My brakes also got very bad at this point, Scary for all that day

I boiled mine on the way home from work across the moor on Friday. balls out straights followed by a 90 degree or sharper corner will tend to do that. I found that you could feel them starting to fade slightly on one corner, the next one the pedal went to the floor almost, and i had to pump it.

in fact it went full travel without much of a braking effect.

Right so, therefore the fluid/ gas must have compressed up in order for it to do that.
If it was pad lift the pedal would stay relatively hard, the pads moving int the opposite direction to the fluid pushing against them would not let the pedal sink down....

there was a brake burn smell,

Right, so you overheated them, and the heat began to transfer into the fluid rather than to atmosphere.

Thats what i think anyway.



Anyhow, whats a litre of brake fluid, more than enough to do the whole system on a non abs car, a tenner? think its worth changing it anyway for that money.

dragon wrote:Now, call me picky, but how do we know that site has corrrect info?

I agree with that site. The only way for the brakes to do that quickly is for the fluid to boil. It then turns into a gas that is compressable, so the pedal will go to the floor.

The same thing happened on a hire car that I had once (someone decided to top up the brake fluid with water) it was more noticable then, because water boils at lower temp than brake fluid.

Richard

water...idiots.

My brakes were nice and new then, i boiled them again soon after, but re-bled and it hasn't happened again.