Not happy with MY04 C4S brakes
06-21-2010, 02:55 PM
#16
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I helped a friend do his Boxster brakes this morning, replacing pads all around and a complete fluid flush. All went w/o problems and the whole process took about 2.5 hours taking my time.
After a break I did a fluid flush on my recently acquired C4S and ran into a couple of issues. First, I did the fluid flush because the brakes seemed a bit soft and I wasn't sure the last time they'd been flushed. After loosening the wheels (the fronts felt like they only had about 20 ft/lbs on them), getting the car in the air and removing the wheels I noticed it had relatively new pads all around. The rears are Textar 4045 and I didn't pay attention to the fronts.
I flushed all the calipers and ran into problems on the rears as the RR inner bleed nipple required quite a bit of torque to get it to stop. I actually had to use a socket to get it tight enough. The LR also required extra to get them to stop but nothing like the RR. I also did the clutch and adjusted the parking brake as it needed about 7-8 clicks to be fully engaged and it's now back to 5.
Anyway, the pedal feels solid and things are fine at normal stops. However hard stops from 70+ just don't seem to bite very hard (my Boxster stops much better on the current generation Porsche pads) and after getting things warmed up it's pretty near impossible to get the ABS to kick in - even while really standing on the pedal.
Is this just the behavior of the Textars? If so, is there anything better available as I plan to do some DE's and really wouldn't want to track my car the way it is now.
After a break I did a fluid flush on my recently acquired C4S and ran into a couple of issues. First, I did the fluid flush because the brakes seemed a bit soft and I wasn't sure the last time they'd been flushed. After loosening the wheels (the fronts felt like they only had about 20 ft/lbs on them), getting the car in the air and removing the wheels I noticed it had relatively new pads all around. The rears are Textar 4045 and I didn't pay attention to the fronts.
I flushed all the calipers and ran into problems on the rears as the RR inner bleed nipple required quite a bit of torque to get it to stop. I actually had to use a socket to get it tight enough. The LR also required extra to get them to stop but nothing like the RR. I also did the clutch and adjusted the parking brake as it needed about 7-8 clicks to be fully engaged and it's now back to 5.
Anyway, the pedal feels solid and things are fine at normal stops. However hard stops from 70+ just don't seem to bite very hard (my Boxster stops much better on the current generation Porsche pads) and after getting things warmed up it's pretty near impossible to get the ABS to kick in - even while really standing on the pedal.
Is this just the behavior of the Textars? If so, is there anything better available as I plan to do some DE's and really wouldn't want to track my car the way it is now.
With regards to bleeding...how did you cycle through the ABS (i.e. - bleed the ABS) if you don't have that Porsche machine thingy? I'm thinking that's the cause of your issues.
As a data point, my 2006 Boxster S has much nicer brake feel than the 996.
06-21-2010, 03:05 PM
#17
The Penguin King
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06-21-2010, 03:06 PM
#18
Burning Brakes
Thread Starter
What tires are you running? and what are their condition?
The C4S is not 2900 lb boxster. Crappy tires will effect braking by triggering ABS and PSM in some situations.
The OEM brakes pads really never have biten hard on my C4S but they do bite and slow you down pretty damn amazingly. They will trigger ABS on a harder compound tire easily. If you want pads that bite amazingly try Pagid yellows but if you have crappy tires, your going to have ABS engage even more.
The C4S is not 2900 lb boxster. Crappy tires will effect braking by triggering ABS and PSM in some situations.
The OEM brakes pads really never have biten hard on my C4S but they do bite and slow you down pretty damn amazingly. They will trigger ABS on a harder compound tire easily. If you want pads that bite amazingly try Pagid yellows but if you have crappy tires, your going to have ABS engage even more.
i have a feeling you are leaking a little bit of brake fluid at the bleed nipple somewhere. If you have access to another person, have them stare at all the calipers while you pump the brakes w/ the car off. I'm betting there is a tiny bit of fluid that's coming out indicating the nipple is FUBAR'd. Had this happen to a friend's STI at Laguna Seca.
The brake bleed nipple should be not overly tight at all. Somewhere in the 9 ft lbs.
The brake bleed nipple should be not overly tight at all. Somewhere in the 9 ft lbs.
06-21-2010, 03:16 PM
#19
Burning Brakes
Thread Starter
I have a 2004 996 C4S and just came from the track. The brakes are stock and I got into the ABS with no problems.
With regards to bleeding...how did you cycle through the ABS (i.e. - bleed the ABS) if you don't have that Porsche machine thingy? I'm thinking that's the cause of your issues.
As a data point, my 2006 Boxster S has much nicer brake feel than the 996.
With regards to bleeding...how did you cycle through the ABS (i.e. - bleed the ABS) if you don't have that Porsche machine thingy? I'm thinking that's the cause of your issues.
As a data point, my 2006 Boxster S has much nicer brake feel than the 996.
I've never done the ABS when bleeding/flushing and my understanding is that's it's far from mandatory to do so.
06-21-2010, 03:53 PM
#20
how long have you had the c4s?.... fwiw, these brakes feel a little soft at first touch of the brakes, at the last 5-7mm of brake travel is when you really starts to brake very quickly. Maybe this is what you are feeling?
06-21-2010, 04:29 PM
#21
Burning Brakes
Thread Starter
I've had the car a bit over a month and they've seemed less than grabby since the beginning. I had chalked it up to needing the fluid flushed but that didn't change anything. The only comparison point I have is my 2000 Boxster S which has terrific brakes that grab fairly early on.
I did note that during yesterdays trial runs to fully test things that it does pull down the speed pretty quickly and I can actually feel the change in G's once stopped. So it may just be that things have enough grip that it's really very hard to get the ABS to engage in dry conditions with the Pilot Sports. I'll have to find a wide open space to try it in the wet to see what happens as far as the ABS goes.
I did note that during yesterdays trial runs to fully test things that it does pull down the speed pretty quickly and I can actually feel the change in G's once stopped. So it may just be that things have enough grip that it's really very hard to get the ABS to engage in dry conditions with the Pilot Sports. I'll have to find a wide open space to try it in the wet to see what happens as far as the ABS goes.
06-21-2010, 05:11 PM
#22
1- bleed/flush the brakes
2- drive on the street and get the ABS to activate a few times
3- bleed/flush the brakes again
4- profit
Now... the OP says that he can't get the ABS to come on so this won't work for him...
/m
(And I finally got what your username means...)
06-21-2010, 05:23 PM
#23
Burning Brakes
Need to replace a couple of the bleeder nipples on my calipers as well. Are they Porsche specific parts or can you get them at a good parts store?
If Porsche specific - can someone supply the part numbers?
If Porsche specific - can someone supply the part numbers?
06-21-2010, 05:34 PM
#24
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No. I have PS2's and have had no issues going into ABS even when they were "hot" on the track. Something is wrong. Since you were not the original owner, I'm thinking you may have bargain basement pads... As a data point, the stock pads on my C4S performed flawlessly on the track. I was very surprised actually since I was used to running Hawk Blues (which as most would agree, is the non-fade, stop on a dime, pad). After 2 days of DE, it didn't even seem like much wear on the pads. I was making the same comment to a gentleman who was running a GT3 with stock pads also.
06-21-2010, 06:46 PM
#25
Burning Brakes
Thread Starter
I know who the PO was and that they wouldn't have worked on the car themselves. With that in mind, since the rears are Textar T4045 pads I'm assuming (I don't want to pull the wheel as it 90 degrees out) that the fronts are the correct matching part as they also look new - but not enough sticks out to read the make. Also, the Textar pads are OEM replacements with a Porsche p/n so they *should* work reasonably well on at the street. That's my main concern at the moment.
I think I'll run it by the dealer tomorrow and see about a quick test drive.
I think I'll run it by the dealer tomorrow and see about a quick test drive.
06-23-2010, 01:58 PM
#26
Burning Brakes
Thread Starter
Here's a final update...
I headed over to the dealer around lunch time today. On my way over the brakes felt better but I don't know if that's subjective or a result of the complete bedding in. In any event, I had the service mgr check the car as all the techs were at lunch and after a few hard stops from 40+ in the back lot he said it seemed normal to him (the ABS did kick in but only right before coming to a full stop). He also said that the ABS on the Boxster kicks in a bit earlier compared to the 996. So for now the (non) issue would seem to be closed.
I headed over to the dealer around lunch time today. On my way over the brakes felt better but I don't know if that's subjective or a result of the complete bedding in. In any event, I had the service mgr check the car as all the techs were at lunch and after a few hard stops from 40+ in the back lot he said it seemed normal to him (the ABS did kick in but only right before coming to a full stop). He also said that the ABS on the Boxster kicks in a bit earlier compared to the 996. So for now the (non) issue would seem to be closed.
