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Discussion Starter · #1 ·
Hi all,

A while ago I replaced my front brakes with ceramic ones from Advance auto. After doing so, the pedal felt "low", so recently I bled and re-bled the system several times. The pedal feel is now firm, but "further away" - I have to push the pedal about an inch further than before to reach that point. This happens even with the car parked, when the brake booster isn't engaging: even if I "pump it up", the pedal travels a good distance before it stops, so it's not related to the braking efficiency of the pads themselves.
I know that S40s generally have a different pedal feel and amount of travel than most cars, I noticed that when I bought my last S40. What I'm experiencing now is definitely outside the bounds of that normal behavior though.

Anyone experience something similar?
Thanks!
 

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Well, its the pads obviously. They might be soft, or not flat, or whatever. Advance Auto? Really? Sorry, but the savings really isn't there, in the end.
 

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Discussion Starter · #3 ·
Well, its the pads obviously. They might be soft, or not flat, or whatever. Advance Auto? Really? Sorry, but the savings really isn't there, in the end.
How does it go, cheap man pays twice? Something like that...

I'm having trouble wrapping my head around the pads causing pedal sink even when the car is stationary. Perceived sink due to poor performance while braking - sure, but I can't imagine how wonky shaped they have to be to give the pedal extra travel while stopped. Swapping them is a cheap thing to try if all else fails.
 

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I'm not going to give you grief about the pads - I use Autozone and Advanced Auto and Oreilly so I'm far from a Volvo OEM Purist there - ceramics are longer lasting than organics but are harder on the rotors - do what your comfortable with.

Having upgraded mine to carbon ceramics - there was no physical change in pedal travel for me. This indicates to me that you have a small air bubble somewhere.
Having bled mine with no pedal travel change - this also indicates that you have a small air bubble somewhere.
Having pumped mine with the car off - the pedal gets RIDICULOUSLY stiff. If you have travel - it either means your slave/master is going bad or you have an air bubble somewhere - given that it was good before the pad change and bleed, I would vote for air bubble.

Please enlighten us as to the procedure you used to push the pistons back in the calipers for the new pads and how you bled them to avoid any newbie issues that can arise from improper methods.
 

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The issue was seen just after swapping the pads and the hydraulics weren't touched yet, right? It is indeed possible it's the rear calipers hanging up after being wound back. Was either one stiff, or the bracket heavily corroded? If so, a trip to the grinder might help.

I still think it's the pads.
 

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Discussion Starter · #6 · (Edited)
The issue was seen just after swapping the pads and the hydraulics weren't touched yet, right? It is indeed possible it's the rear calipers hanging up after being wound back. Was either one stiff, or the bracket heavily corroded? If so, a trip to the grinder might help.

I still think it's the pads.
This is correct. I noticed the issue prior to any bleeding. I had however only swapped the fronts - rears had been replaced a couple thousand miles prior with no issues. I didn't notice any irregular behavior with the pistons, they retracted readily. The brackets weren't perfect, but with some wire brushing didn't cause the pads much grief in moving about.

I'm not going to give you grief about the pads - I use Autozone and Advanced Auto and Oreilly so I'm far from a Volvo OEM Purist there - ceramics are longer lasting than organics but are harder on the rotors - do what your comfortable with.

Having upgraded mine to carbon ceramics - there was no physical change in pedal travel for me. This indicates to me that you have a small air bubble somewhere.
Having bled mine with no pedal travel change - this also indicates that you have a small air bubble somewhere.
Having pumped mine with the car off - the pedal gets RIDICULOUSLY stiff. If you have travel - it either means your slave/master is going bad or you have an air bubble somewhere - given that it was good before the pad change and bleed, I would vote for air bubble.

Please enlighten us as to the procedure you used to push the pistons back in the calipers for the new pads and how you bled them to avoid any newbie issues that can arise from improper methods.
The pistons were pushed in with the brake pad attached, using a C clamp. I forgot to open the reservoir cap, but realized this after having barely retracted the piston. Another error: caliper slipped out of my hand and hung by the line. Hung it back up, have been keeping an eye on that line - no leaks or anything abnormal. Internal damage possible?
Bled with the 2 person method twice - pressure on pedal, open valve, close valve, release pedal. Drove for many hundreds of miles.
Bled with Motive bleeder twice as well. Bled rears too, despite only having swapped front brake pads.

My pedal is also very stiff once pumped, just with an inch of travel prior, which is stumping me. No pedal sinking over time, either.

Thank you both for the replies!
 

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Discussion Starter · #7 · (Edited)
Update:

For peace of mind, replaced the line that had the caliper bungee jump off of it. Slightly improved feel after that and a bleed.

Another observation: the new pads take up the whole rotor whereas the old ones left outer and inner ridges on the rotor face untouched. I would have said this is the culprit in the odd behavior, but the ridges left by the previous pads have completely worn down flush with the rest of the rotor surface, so any strange seating of the pad on the rotor seems to have resolved itself with time and use.
 

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Oh, riding the ridge would absolutely explain this. I wouldn't bet it's completely worn down yet, it takes only a little gap to make the pad rock and roll.

New rotors don't break the bank, btw. But you'll have to replace the new pads too. If you're happy with things as is, then just drive it!
 

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+1 to that - glad to see it was an exterior condition and not user error (bubbles or bad slave/master).
 

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Discussion Starter · #10 ·
Yeah, I guess the ridge x2 for each side of the rotor x2 for each of the rotors can be of more consequence than I think. The rotors were replaced at the same time as the pads preceding these, so I anticipate it won't take too long to wear the ridges down all the way.

Interestingly the replacement of 1 line was the biggest positive improvement - I was about to head out to swap the pads, but the brakes were behaving well enough that I couldn't remember if it was better or worse than before the replacement.
Thought "better" of it, in favor of not winding back the (as far as I know original to the car) front calipers an extra time.
 

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It's the pads that wear to the rotors, not the other way around. That's why it feels funny, the softer material is moving.

If you like the feel of hard brake pedal action, get some stainless braided lines, and new pads/rotors. Bed them in properly and it'll be night and day. But for a DD, maybe not.
 

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It's the pads that wear to the rotors, not the other way around. That's why it feels funny, the softer material is moving.

If you like the feel of hard brake pedal action, get some stainless braided lines, and new pads/rotors. Bed them in properly and it'll be night and day. But for a DD, maybe not.
+1 - One day I'll be doing this too. That being said get some DOT approved SS brake lines - otherwise there is a chance your insurance will have a field day with your car should you be in an accident and they are smart enough to know the difference. Someone on here was unlucky enough to get a bad one and had it burst on them while doing some stopping at a traffic light, but otherwise, I have heard of absolutely no bad news with quality SS brake lines, and I use them on my Harley as well.
 

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Discussion Starter · #13 ·
It's the pads that wear to the rotors, not the other way around. That's why it feels funny, the softer material is moving.

If you like the feel of hard brake pedal action, get some stainless braided lines, and new pads/rotors. Bed them in properly and it'll be night and day. But for a DD, maybe not.
Yep, but even so the rotor ridge has worn down a good deal - assuming everything else is proper and works well, I'd think they'll eventually "mate" to have full contact.

On the topic of SS lines - I'm consciously trying to limit the hand itching "make it better" illness. After all, it's a 210k mile 2.4i commuter. I swapped my brake line for a Duralast one which was very well made and looked identical to the OEM, matches all the same SAE standards. Decided not to touch the other side for now.

I considered sheathed StopTech SS lines (ironically some of the cheapest and most readily available I could find), but they return a non-zero failure rate when googled, and ought to be checked more regularly than rubber.
 
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