Ferodo DS2500 fitting problems

[KL_RCS]

Hi,

I'm trying to fit some DS2500 (FCP565H) to my 182 (together with new Brembo HCs) but am having problems....the caliper bolts are not aligning because the pads seem too wide.

http://i1183.photobucket.com/albums/x467/krislowe2/DSCF0521.jpg

It seems that about 2mm needs to come off to get the caliper to close. Is it normal to have to grind down the bits arrowed in red?

Thanks,
Kris

 

[Fred@BTM]

yeah sometimes they need a dress down with a grinder

you HAVE to remove the stock shims in the pad carrier and MAKE SURE the pad can move vertically by AT LEAST 1mm when in the carrier, (you will have to dress the nobbles down on each end of the back plate)

 

[KL_RCS]

Thanks Fred. Yeah was aware of the vertical play but not the side to side probs. They've gone in now with some filling down. This was only required on the inner one. And yes, the shims are outa there. Just need to bleed, then time for a test drive

 

[aldo_87]

whats the reason for removing the shims?

 

[KL_RCS]

See http://www.cliosport.net/forum/showthread.php?530540-ds2500-correct-part-number-for-182-cup

 

[Fred@BTM]

if the pads aren't free to move in the carrier, when they got hot (ie expand) they bind on - which overheats the material/disc - fucked in no time, same for the "correctly fitting" (ahem) 406H pads that another company sells

 

[KL_RCS]

Okay, so I finally went for a short test drive; 3 miles at 30-40 mph with moderate braking. I got back and both front discs were absolutely roasting, I couldn't touch them for any more than a second. Is this normal for new pads/discs or am I being premature and need to give the brakes some stick before they start to move freely?

I intend to carry out a proper bedding in sequence as per Ferodo recommend and followed all the advice on here; filed down pads, cleaned and re-greased everything. I also coated the calipers/carreirs in two coats of Hammerite. I didn't paint the top and bottom pad touch points but did do where the caliper touches the outer pad. Not sure if this would have anything to do with it. The caliper was quite a tight fit between the pads when I closed it and spinning the disc by hand afterwards was a bit of a struggle.

Any ideas?

Thanks,
Kris

 

[aucky]

You TOUCHED your brakes after using them?????

 

[KL_RCS]

Got sorched fingers to prove it! Not something I normally do, but even the alloys were slightly warm to the touch which can't be right as I'd done very little braking considering.

 

[Ian_s]

Your wheels will get warm with normal driving, driving properly you shouldn't be able to touch them!

 

[Munson]

FPMSL at touching your brakes after using them

 

[p@blo]

Indeed. The stainless shims defy physics and have a different vhc to all other SS in the world in terms of their expansive properties. When heat cycled, the shims puff up like expanding foam iirc. :dead:

 

[KL_RCS]

I've removed the shims, and didn't get any squeeling.

 

[p@blo]

@ KL-expert forum opinion would apparently dictate they squeal 'with' the shims.

Something or other to do with ~mil thick stainless freakishly expanding a gazillion times its original volume when heated iirc.

Sounds pretty dangerous

 

[Xanda73]

You TOUCHED your brakes after using them?????

With this kind of mindset, how is the op still alive?

FPMSL

 

[aucky]

With this kind of mindset, how is the op still alive?

FPMSL

Caveman mindset?

The warm alloys should have been the first clue.

Fire burn. Ouch
Fire burn. Ouch.
And repeat

 

[Fred@BTM]

Indeed. The stainless shims defy physics and have a different vhc to all other SS in the world in terms of their expansive properties. When heat cycled, the shims puff up like expanding foam iirc. :dead:

The pads expand, not the shims

 

[p@blo]

Interesting... So if the expansive properties of the pads can be considered a constant between shims/no shims, & if as stated the shims don't expand significantly- then what is the actual reason that having the shims in is an issue? Bearing in mind the frictional properties of ss versus the rough arse cast of std carriers the pads sit in mind, the science behind all this must surely be pretty fascinating

 

[Fred@BTM]

simply you bin the shims so you don't have to grind the pads down as much, same on the clio cup cars, shims were removed on them

i'll post some pics tomorrow of what happens to the pads if you dont grind the back plates down/leave the shims in - whatever way you want to do it

 

[p@blo]

Fair enough, but still doesnt answer my question by giving any kind of factual reasoning. I'll get some pics of mine that were properly prepped & run with shims too (in exactly the same way as if ground to sit with sufficient clearance with just the carriers). Funnily enough, after ~8000 miles incl track use theyre absolutely fine. No squeal, no binding, consistent feel etc. Regardless of shimmed or not its surely common sense any pad would overheat if its not fitted properly & binds? Im just curious to know the reason why mine seem to have behaved nothing like the expert opinion would consistently lead us to believe.

 

[Fred@BTM]

pads (regardless of what car or caliper) must be free to move in the pad carrier or caliper, billy basic rule for motor cars/race cars etc

If you try and fit DS2500 into the carrier with the shims in place it WILL NOT slide straight in with just finger pressure

by removing the shims the pad will fit in the carrier with slight force, hence why it is advised to grind the nobbles at each end of the back plate so the pad can move vertically by at least 1mm

as you correctly point out everything will expand when hot, not just the pad, so then in theory if you have 1mm gap when cold you will still have a gap (albeit slightly smaller or larger depending upon charateristic of different materials) when hot, if the pad is tight in the carrier when cold then its going to tight when hot = bad

get the idea?

 

[Fred@BTM]

here's the pic

as you can see the edges of the braking material has disintergrated completey (you can crumble the material off with your fingers)

i had to use a hammer to get those pads out of the carrier, they should lift out with just your fingers