So I bought some Ferodo DS1.11 pads from a guy on the meg facebook group. They're newish, having only been used for testing in the clio cup race series. I stripped and cleaned my brakes yesterday, brakes are in really good condition. Pistons and seals look almost new. Then I fitted the pads with Mr Pink pins. This evening i've been out to bed them in properly. Did 10-20 hard brakes from 70ish to 30ish, which was enough for me to be smelling the brakes. They perform well with great power - However, my car is pulling to the drivers side under heavy braking. The car kind of corrects itself, this may be the stability control I don't know, but if I braked hard whilst loosely holding the steering wheel, it pulls to one side and the steering seems to almost counter this itself. The car may have done this before as i've not had the car long, but this is the first bit of really heavy braking like this that i've done. It pulls enough to make me think it'd be quite unstable on a trackday. Anyway, got home and checked out the discs. Both are covered with a fair layer of pad material, so i'd say they have bedded in well: But the passenger side, i'm not quite sure whats happened but the outer 10mm of the disc has a darker ring: To me, something isn't right here and it would explain why the car pulls to the drivers side if the passenger side isn't performing properly. What are peoples thoughts on this?
It looks more like the pads not making contact with that portion of the disc, usually if it's getting too hot in an area the surface goes towards a blue tinge where as brown is usually the surface oxidising because it's not getting cleaned off by the pads i.e a lack of contact. I'd take the pads out and take a look at the material surface to see if it's relatively even or not.
Yeah I think you're onto something there. If they're not even, are they just scrap these pads? Suppose I could try a trick i've used before to even out engine parts to ensure they're flat - Glue a piece of coarse sand paper to a piece of MDF, then sand the pad flat on that. Not sure if it'd work.
Or just keep driving it so the higher part of the pad wears down , won't take long before it becomes even
Yeah, well next time I can touch them is at the weekend anyway so should have another 100 miles of daily driving on them by then. Depends how far off they are I suppose
It will work. A friend of mine used to glaze over his pads in his race car when he started racing, he tended to brake for far too long and hang on the peddle a bit, long way into the corners (like very gentle trail braking). Between every race his mechanical support would sand the pads just like how you describe it with wet and dry paper to dull off the glazing.
I guess the problem will be getting them level again using that method - i.e. if they're worn at an angle now, i'll need to sand them as an opposing angle to even them out. Otherwise i'll just be wearing them out but at the same angle
Hi they will get there quite quickly, i have done 3 track days and driving to the tracks and i think i have one more track day left in them. All the brake dust is over the back of my car :rolleyes:
In that case, I might sort them out so they're braking properly and then put the standard pads back in until I do a trackday. Not much point wearing out a set of expensive pads like these doing normal road driving. I had DS2500 in my 197 and they were a decent upgrade over standard, but still lasted well (15k+ miles) on the road. Where as if these are gona wear out in a few thousand miles, it's not worth keeping them in as I doubt i'll be doing a trackday in the next 6 months anyway to be honest.
Well thought i'd update this as i'm baffled now. After a couple of weeks the pads seem to have bed in more and the pulling to one side has stopped. No matter how hard I brake now, it brakes bang on straight. However the near side disc still looks like this on both sides: So though't i'd take them out for a closer look: The pad does look worn at an angle I think. This is the same for both inner and outer pads: So I measured the thickness of the pad in each corner: Clearly there is some uneven wear, but I don't know what could cause this? So i used some wet and dry on a piece of MDF and using trial and error sanded the pads until each corner measured +/- 0.2mm and put them back in. So that was a week ago, there has been no difference in braking performance that I can really feel. But now the disc looks like this: So clearly I have made the issue worse... I don't know what to do now. The pads work well, I can feel the massive extra power over the standard pads, but clearly they're not working as they should.
I would suggest the pads are sticking in your calliper slightly or the callipers themselves could do with a strip down and rebuild.
why dont you swap the pads for drivers side to passengers side and you can then see if the problem moves to the other side.
Hmm maybe. But the callipers were thoroughly cleaned and these pads were greased on the back and sides on installation. When I did this I thought the callipers looked in really good condition. The seals and pistons look as new to me: This is how the problematic passenger side looks after a few weeks of running these pads: Also I didn't have this problem with the standard pads, only after fitting these DS1.11 pads. Yeah thats an idea, i'll try this.
The pad itself might be a little tight in the calliper, Maybe worth shaving it a mm or two and seeing if that helps
As said by grumpy already it looks like the pad isn't making contact with the surface. It'll be the pad at fault. I bet if you swapped it to the other side it'll just move the issue to that disc. The pad surface obviously is the issue. Either sand them completely flat, run them and risk a rusty band on the disc or bin them and buy a new set
