squishy brake pedal

whitenblue65 · Jun 25, 2009, 02:32 AM

I tracked my car the other week and basically killed my brakes (see pictures below). the rear brakes are OK, but the pads on the front basically cooked off during the last session which I'm sure lead to boiling fluid and burning caliper seals. The seals on the front calipers look pretty toasted but I put everything back together after sanding the rotors down and putting on new pads without replacing the seals.

After bleeding the brakes 4-5 times including using a pressure bleeder 3 times which I no doubt flushed the entire system at least twice over with I still have a soft pedal which goes down further than normal until I pump it 1 or 2 times. I would think because the pedal goes back to normal after a pump or two it would still be air in the lines but theres just no way there could be after all the bleeding I did. Does anyone know if this could possibly be because of bad seals or is there something else wrong with the caliper I could be missing?

...Racing Brake pads "guaranteed fade free to over 1200 deg. F":
http://picasaweb.google.com/lh/photo...eat=directlink
http://picasaweb.google.com/lh/photo...eat=directlink
http://picasaweb.google.com/lh/photo...eat=directlink

tripperfx3 · Jun 25, 2009, 02:35 AM

Can't see the pic, but what brand pads do you have and do you still have stock brake lines? I experience squishy breaking with my Girodisc magic pads if I slam on the breaks and its probably also due to flex in the brake lines as well.

whitenblue65 · Jun 25, 2009, 02:43 AM

I've never uploaded pictures to a forum before, does anyone know how I can get pictures from Picasa or my computer to the site? I have stainless braided lines with "Racing Brake" RB ET800 pads which are supposed to be good up to 1200 degrees F. I always had a firm pedal before this and should still have one with no air in the lines and new pads...

tripperfx3 · Jun 25, 2009, 03:04 AM

Not sure about Picasa, but what fluid are you using. Could be cooking that. Other than that I'm not sure. It just seems like air in the lines wouldn't be the issue given how many times you've bleed it.

As you've already said check the seals. Are you possibly leaking fluid while breaking?

whitenblue65 · Jun 25, 2009, 02:44 PM

I'm using pretty good DOT 4 fluid, it's not the extremely expensive race stuff, but should be fine for track days and especially the street. I'm sure it cooked the fluid when I was on the track but I've flushed the system out at least once since then.

I just looked up some caliper rebuild kits and I think I'll try putting all new seals in and see what that does.

Neteru · Jul 1, 2009, 08:50 AM

can anyone post a picture of the caliper seals so i know what they look like?

Carlyle · Jul 1, 2009, 10:31 AM

if you google it, you should find the seals

**SmikeEvo** · Jul 1, 2009, 10:42 AM

Looks like you melted off the pad material.

Did you follow the right bleed order?

Yep on seals, and you might want a more dedicated track pad with a higher MOT.

maxGdsm · Jul 7, 2009, 10:53 PM

any update on this? im having a similar situation with one of my DSMs. Ive bleed multiple time, purchased new calipers and master cylinder, new braided lines and pads and rotors and still the pedal feels soft and like it goes too far down before engaging hard.

Pure EvoIX · Jul 7, 2009, 11:20 PM

im getting same problem. I had to bleed once after session 2, even though i bled the lines before the actual track day.

I have Raybestos ST-43 F/R , Stoptech S.S. Lines, Motul 600 Dot 4, Ti shields for the pads, stock replacement blank rotors.

Bump for solutions. Could it be the thickness of pad, too little = more pedal pressure? Or caliper seals and dust boots need replacing? Need brake ducting?

ajstefanacci · Jul 8, 2009, 12:05 AM

run dot-5 on the track. and when you bleed make sure the fluids coming out clear and then do it once more.

Ferreira · Jul 9, 2009, 07:49 PM

Quote:

Originally Posted by ajstefanacci

run dot-5 on the track. and when you bleed make sure the fluids coming out clear and then do it once more.

Shut up fool. DOT5 is silicone and more compressible than the glycol in DOT4. Plus its terrible on the ABS.

If the seals arent leaking then they're not causing the mushy pedal.

You need to gravity bleed the system. Open all the bleeders on all 4 corners and let it bleed by itself onto some drain pans. The corner that is not dripping then that corner has air still. Close all the others and softly pump the pedal to bleed. Close the bleeder before letting off the pedal and repeat until its all set.

You should get some Performance Friction pads. Their dual purpose Z rated stuff is really good as it doesnt make any noise dust and is good on the street and when hot it bites real hard. You could also get some track pads but those dust and make noise.

DEVO330 · Jul 14, 2009, 03:26 PM

with years of track time at MSR
i found i could get a harder pedal if i bled the
right rear INSIDE nipple first then the outside

whitenblue65 · Aug 2, 2009, 09:11 PM

I fixed the pedal so it's rock hard...turns out I never realized there were two bleed valves on each caliper and I was only bleeding the outside one each time. Lesson learned (after 5 bleed jobs haha)

EvolutionBOOM · Aug 9, 2009, 08:24 PM

bleeded it?