C12 Brake upgrade, DS2500 pads

[Beaky]

So collected the car today and initial observations are that the brakes take a few prods to heat up but then are very potent.

 

Obviously they still need to be fully bedded in but general pedal feel and speed retardation is very good.

 

The one issue I have is on both front wheels (7") clearance the balancing weights had to be placed on the outside to clear the caliper.

 

Steve believes that a more sophisticated wheel balancing machine than the one they have in the garage maybe able to resolve the issue.

 

 

[SP72]

Time to find some 951 7" upfront front. Clearance must be really tight for weights to make a difference!

[ALEX P]

Lets have some pics of the C12s fitted Chris.

 

You are running 16's not 15's right?

[Richard Bernau]

Small spacer should fix that if you have the clearance.

[Beaky]

Lets have some pics of the C12s fitted Chris.

 

You are running 16's not 15's right?

Yup, 16's, will take some photos today

Small spacer should fix that if you have the clearance.

I think Steve was already running a small spacer on the front for me, will need to check

Time to find some 951 7" upfront front. Clearance must be really tight for weights to make a difference!

Hi Shirish, I assume 951's come from a 944, I know that have the same off set, but what else is different?

Edited April 30, 2016 by Beaky

[SP72]

Some light reading: http://rennlist.com/forums/924-931-944-951-968-forum/325456-tech-lesson-16-fuchs-variants-and-differences.html

 

I thought you already had shims upfront?

[Beaky]

Some light reading: http://rennlist.com/forums/924-931-944-951-968-forum/325456-tech-lesson-16-fuchs-variants-and-differences.html I thought you already had shims upfront?

Thanks for this, looks like I need to source a pair of 951's, or borrow one to set fit the acquire a set

one to set fit the acquire a set

To test fit that should read!

[map]

Thanks for this, looks like I need to source a pair of 951's, or borrow one to set fit the acquire a set

To test fit that should read!

 

If you get stuck finding a pair of 951 fronts to test fit let me know - would be able to help you albeit I'd need to extract them from storage.

[Beaky]

Looked at taking a few photos but since I opted for black units with no engraving not much to see and most of it is covered by the wheel

[Beaky]

So last night it was the first time I had a chance to take the car for a good spin, some nice B roads north of Barnet and then back into town and around the west end........its amazing how appreciative folks are about an old Porsche,so many compliments and from a very wide age range.

 

Anyway back to the brakes, doing both front and back with the larger 300 disc's has from what i could feel meant there is no need to adjust the bias.

 

With some heat in them, they do stop very well, will need a good track day to evaluate any fade, but good so far.

 

My only bug bear is that sometimes on start up there feels to be a soft pedal with move travel that normal, prod it once, twice its gone, so maybe needs to be bled again, or still just bedding in.

 

So good stopping power and weigh savings but at a cost around £3.5k inclusive of braided hoses, oil etc. and VAT

[johndglynn]

My only bug bear is that sometimes on start up there feels to be a soft pedal with move travel that normal, prod it once, twice its gone, so maybe needs to be bled again, or still just bedding in.

I don't think that is normal - never noticed it on any of the C12 cars I have driven. They are a good product.

The 4-piston caliper sets are something like £1600 from Tuts so a bit cheaper. Easy fit under 15s.

[Richard Bernau]

Any clues on the soft pedal?

I had a soft pedal when I bought my car. Turns out the vacuum operated headlight adjustment canister was cracked and that was the culprit. Don't ask how that all fits together and traces back to brakes, but that was it. The canister is on front of the clock IIRC.

[SP72]

If it is vacuum related, another check:

http://forums.pelicanparts.com/porsche-911-technical-forum/435952-vacuum-leak-you-probably-didnt-ever-think.html

[Beaky]

Drove to Honfleur and back over the weekend, brakes were super and now no issue on start up, but once after a high speed sharp corner on first application of the brakes i got a longer travel than normal, then the brakes were back to normal.

The cars in for its annual service next week, so I'll have then check the the vacuums.

[Beaky]

Just took the car out to go to Smithfield meet, brake pedal was very soft then when to the floor.

Quick ckeck and it looks like both rear calipers are leaking!

I believe Richard also had an issue with these C12 leaking, anyone else have an issue?

[Richard Bernau]

I did and I needed the callipers rebuilt with new seals IIRC. It's in a thread on here somewhere. There was an updated part I think.

[Beaky]

Thanks Richard.

Both have been shipped back to C12 so fingers crossed

[Beaky]

So C12 took the calipers apart, could not find any issue with them rebuilt them with new seals and replaced their rusty bolts - seems they are washing their hands of any responsibility on the cost.

Well tell that to my right foot that took the pedal to the floor or the oil splattered over my wheels and arch liners or the oil seen dripping from the calipers.

When I first fitted these occasionally I'd get a slightly soft pedal ( as documented above), so I think the issue was always there but only manifest in complete failure last week.

So glad they have been rebuilt free of charge - only time will tell if it's a permanent fix, but really disappointed they have not as accepted responsibility.

[Beaky]

These bloody brakes are leaking again!

The only common denominator that I can identify is that it occurs when the temperature gets very very cold!

[GaryH]

The only common denominator that I can identify is that it occurs when the temperature gets very very cold!

Has your ring shrunk in the cold!?

[BenC]

that's really sh!t - sorry to hear that. especially considering how much a full set costs to install.

Hope you find a way forward

[Beaky]

This is the options I have been given -Right okay, well the options ahead of us are either I have them back again and fit pistons up on tolerance to cater for any play in the seals (actually common practice when the seal batches are high on their manufactured tolerance) And see how that is, or I can manufacture you a new pair of calipers, or offer you a refund on the rears if you are not happy with the other options or how I've handled the problem.

Is option 1 just a short term fix that will manifest itself again early in the future, will a new se just have the same issue?

What you you folks suggest I do

Has your ring shrunk in the cold!?

Always......................................

[Nige]

New pair of calipers or refund. Wouldn't entertain trying to make the existing ones work.

[reddevil]

New pair of calipers or refund. Wouldn't entertain trying to make the existing ones work.

^ this.

[sladey]

I agree - best option. I've never heard of this happening with these Calipers before, and while I'm not a dealer or anything it's such a small community and quite a lot of them have been fitted so I think we would have heard horror stories if it was a regular problem. Think you must have just been unlucky - and I'd take the easy way out