Basal Skull

I had wondered when and how the brake accumulator was going to go bad.

So my brakes were not feeling quite right. I wasn't sure if it was just the CCM set up or something else. Pedal feel wasn't as firm as I thought it should be. Seemed to be getting worse. I've bled the brakes multiple times since getting the Racing Brake kit. I go through quite a bit of brake fluid in general. I only use Castrol SRF. Then I noticed when I bled the accumulator this time, some 'whitish, cream coloured' brake fluid towards the end. That's strange? is it water?
The cream colour, after sitting for a bit, changed and looked liked normal clean brake fluid. It is air. Where's the air coming from? Well, I had to change the clutch accumulator at 44000 miles (before I eventually deleted the power system all together) and it looks like a similar unit. When I took it out, it was completely full of fluid and I wondered where the ?nitrogen on the other side of the membrane (as I understand it) went. I think the brake accumulator was leaking nitrogen into the brake system.

New accumulator in, bled multiple times (pressure bleeding always worked best for me). Although better, still didn't quite feel right. Then read David Donohue's post (post #93 https://rennlist.com/forums/showthre...ferrerid=28499) where he says he had to use old fashioned pedal bleeding method. So had my wife pump the brakes to help me bleed the brakes. Back to normal! I think a rapid pump of the brake pedal shoots out much more fluid at higher pressure along with any small trapped air bubbles better than pressure bleeding with constant pressure.

I'll be at the track in the AM.

Also, I think I'm only going to get two track seasons on the pads (RB calls track/street compound). I could only get one season on the plagid yellows so that's an improvement i guess. I have noticed progressive increase in the amount of brake dust lately, and I notice the surface of the CCM is not as smooth as it used to be, there are some rough spots. I'll take some pics tomorrow. I will also switch to the sintered "healing" pads when these pads are done.

Basal Skull

Front

Basal Skull

Rear look better

OverBoosted28

One session on a set of pads? You must be screaming around that track :-). I am going deeper, trusting things more, but I am sure, I'm not very close to digging that deep on them. Any problems with detached retina? :-0

rockdoc

I had the same issue with the brake booster pump and accumulator recently. It was pretty scary when it went out because without power assist it was difficult/impossible to stop the car even going 25mph. Even though the brake booster pump was leaking near the battery, my mechanic also suggested changing the bomb (accumulator) at the same time. It did take a while (about a week of daily driving) for the brakes to feel normal again because it was difficult to get all of the air out of the system.

Basal Skull

Season, not session!! That would get very expensive! My retinas are ok but started to get floaters a year or two back.. never turned into detached retinas though, that would be bad


I guess these parts can't last forever, be careful guys!

Basal Skull

My pads are done. I had calculated the front/rear bias (post 60 https://rennlist.com/forums/993-turb...-brakes-6.html) and noted increased rear bias vs stock. I can confirm they work fine with the increased rear bias. Front and back pads wear evenly/at the same rate and both needs to be replaced at the same time. With the stock or giros, I was requiring 2 sets of front pads for one set rear. Looks like both fronts and backs are done! Lasted 2X as long as plagid yellow fronts on giros for my use. Rear
Front

Basal Skull

I guess I over did it. I didn't go back on the track after the above pictures. I didn't notice pads being completely gone, thought I had a few mm. I can't see the pads from the top of the caliper because they are so big and there's no clearance between it and the wheel. I thought pedal travel might have increased slightly on the 3.5 hour drive home, stopped fine. Thought I heard a little grinding noise when in a tunnel and applying the brakes. Rotors seem to look fine. The backing metal was bent, one of the pistons took a little more effort initially to push back in when changing out to street pads. Hopefully it's ok, will keep an eye on things.

Mike J

Interesting - not much data on this forum around running ceramics this hard, good stuff.

Even though your pad looks like it's to the metal, you said the disk itself is fine? Wow, it does look Ok in the pictures, but surprised no grooving like on a metal disk.

So next move is just new pads and continue on?

Cheers,

Mike

Basal Skull

I have a set of strictly street pads that I've switched to and will continue on as you say.
Track season is more or less done this year anyways and my tires are also near the end. I'll plan on getting and using the 'healing pads' next year. The ceramic discs are pretty hard the sintered race 'healing' pads are as I understand it pure metal without any binders. No groves at all on the rotors. If anything, the area where the metal pad backing was making contact, the surface looks and feels smoother. Actually on the other worn pads, you can see metal wear indicator exposed on the pads, and on the rotors, where the metal wear indicators touched/made contact, look smoother as well. There are 'lines' around the rotor that lines up with the wear sensors that look smoother - no grooving, actually smoothing or 'healing' of the rotor surface. Really interesting actually.