Poor braking performance

[CoolBreeze]

I'm going to need help on this one guys.
My brakes are officially horrible.
The brakes pedal feels normal but the braking performance is woeful. It's so bad I can't even get ABS to engage even if I try to panic brake as a test.

Things that's been done:
New pads and rotors less than 6 months ago (remsa pads)
New brake fluid and system bled
Calipers were rebuilt a few years ago.

I've troubleshooted:
Pumped brakes with car off, pedal goes hard. With pedal down hard I started the car, pedal moves further down and is soft due to power assistance. All normal here, doesn't feel spongy nor vague... feels like a normal brake pedal making normal brake pedal noises (slight air noise from pedal when pressed)
With car just off held pedal down for 30 secs, then pumped pedal which achieved 3 actions before pedal went hard.
Tested fluid for moisture contamination, all clear.
No leaks, no hoses off, no bad connections.

It just needs a hell of a lot of pressure on the brake pedal to get anything out of them.

ideas?
It's got me stumped

 

[veegeeta]

I would try bleeding them again to make sure there is no air in the system. Possibly the abs unit has shit itself but try bleeding first. Do it with the car running to ensure pedal feel

 

[NuffNuff]

I wonder if you've bed them in incorrectly and the pads are glazed

Take them out and inspect them, sand them or rub them on the footpath and wipe them clean

 

[trotty]

The dreaded firewall flex.

 

[Kaldek]

The dreaded firewall flex.

Surely if that was the case we'd all have the problem as described. Why would one car's firewall flex more than another?

 

[jungle]

Did it just start or were they always like that?

were the calipers disconnected when pads changed? When I fitted my brembos, it took 4 bottles of brake fluid to bleed them properly. Yes 4 the and unit had sooooooo much air in it.

Otherwise also sound like your master cylinder could be the cause if everything else is ok

 

[Kaldek]

@CoolBreeze if you like mate I'm happy to take a look at them and let you compare to my car to see just how much of a difference there is. I also have a vacuum brake bleeding kit.

@jungle has a good point though, in that master cylinders DO go bad.

I'm in South East Melbourne near Dandenong.

 

[CoolBreeze]

Thanks for the replies!
The pads were removed 2 weeks ago to check for glazing, no issues found.

It might be worth bleeding them again but it really feels like a booster / master cyl issue even though they pass a functional check as in original post.
if there was air in the system wouldn't the pedal feel spongy? My pedal is firm but brakes like poo.

The ABS unit is ok, I just don't have the braking power in order to lock up the wheels for it to engage.
Might to worth completely flushing again @Kaldek. definitely happy for you to take a look, you'll see what I mean

 

[NuffNuff]

if you let your car sit overnight is the brake pedal high and hard to press? first press or two and it goes back to normal feel/level?

 

[CoolBreeze]

Just checked then first start of the day, was high and hard to press. But I cant remember if I pumped them last night when I was farting around after turning the car off.

 

[Kaldek]

@Kaldek. definitely happy for you to take a look, you'll see what I mean

Well I'm around most days as I work from home. Even half an hour will help confirm what you're feeling is a legit problem. We could even eyeball for firewall flex.

 

[trotty]

I was joking about flex. How are the pads wearing? Any unevenness inner to outer wear? Sticky caliber Pistons?

 

[CoolBreeze]

Even wear, barely look like they've been used.
All pistons pushed back in without any issues when changing pads.
@NuffNuff Just tested the pedal again after sitting for 3 hours. It got one weak pump then firmed up

 

[NuffNuff]

id look at bleeding the absolute shit out of it man

 

[Kaldek]

Another easy check you can do tonight is to check the brake booster (the big black thing behind the master cylinder).

1. Start car
2. Turn off engine and pump the pedal six or seven times as if you were braking normally
3. Stop pumping, keep your foot pushing down, then start the car
4. The pedal should depress towards the floor somewhat.
5. If the pedal doesn't depress or comes back up, there's a problem with getting vacuum to the booster

 

[CoolBreeze]

@Kaldek
Did this again just before. The pedal depresses once the car is started as it should, though I can floor it out with medium force.
If I floor it out when driving at 60km/h it brakes moderately, but should there not be wheel lockup if the brake is floored? It certainty doesn't throw me into the windscreen with brake force that's for sure.
Checked the brake reservoir cap and the little rubber sock under the cap was all pressed up into itself rather that pushing into the fluid, not sure if that would do anything though

 

[veegeeta]

abs are not designed to lock up but try to push your foot back of the brake. I hate abs lol

 

[Dice]

It should lock up briefly though I was able to do so in my magna too.

 

[Kaldek]

@Kaldek
Did this again just before. The pedal depresses once the car is started as it should, though I can floor it out with medium force.
If I floor it out when driving at 60km/h it brakes moderately, but should there not be wheel lockup if the brake is floored? It certainty doesn't throw me into the windscreen with brake force that's for sure.
Checked the brake reservoir cap and the little rubber sock under the cap was all pressed up into itself rather that pushing into the fluid, not sure if that would do anything though

Does the pedal actually go all the way to the floor when you are testing it while driving?

 

[AKKO]

Just for completeness... are we talking brembos or standard brakes, what's the rubber (tyres) like on all corners?