I finally did a much-needed service and flushed my brake fluid, as well as replacing both front calipers and brake hoses (RH caliper was partially sticking and had leaked a bunch of fluid once... oddly it immediately stopped leaking but whatever, it's replaced now). Used the Motive pressure bleeder that someone here recommended, massively helpful tool.

Since having done that, my brake pedal seems to have a lot more "dead stroke" before initial bite, compared to how much it used to. It seems to work fine otherwise, though I haven't tested hard braking much yet. With the engine running and the car at a standstill, I can still really press down on the pedal enough to hit a bump stop. With the engine off, I can cycle it a few times to drain the booster and I don't remember it feeling unusually soft then. The pedal also feels "slipperier" when pushing the piston through the master cylinder, which IME shows the flush was much needed, and made a difference.

I'm sure a lot of the feeling has to do with the new, correctly working calipers. Does this sound normal for those with a braking system that's known good? Guesstimate says maybe 35-40% of the pedal travel is dead play now, it's hard to tell without actually measuring it. If I remember right, before bleeding and caliper replacement there was maybe half of the amount of dead stroke it has now, with a bit mushier pedal feel, but still being able to hit that same bump stop with engine running and at standstill.

 

Can you pump the pedal several times and have much shorter travel? That would indicate air in the system. I recall reading that the calipers can have a small amount of air that can only be removed by taking the caliper off the car and rotating it slightly while bleeding. A piece of wood equal to the thickness of the rotor would have to be positioned between the pistons.

 

It depends how you flushed the brake system.

@RJ That was my observation, I suggest to people that have worked on their brake system, and then find a soft pedal (hitting the floor) to remove and rotate the caliper so the bleed nipple is at the top, the air can then escape - it's only a small amount but makes all the difference between a good pedal and a sh*t one.

 

Flushed by pumping fresh fluid through using that Motive bleeder, pushing the old fluid out that way.

Pump up doesn't affect travel, I tried pumping it up a decent bit and that hasn't affected travel since the initial setup. They were new empty calipers in the front that I put on, so it's definitely possible that there is still some air trapped in there, since I bled them mounted on the bracket. I'll try taking them off and tilting them around sometime.

 

If pumping doesn't change travel you probably don't have air in the system. Master cylinder problem?

 

Is that amount of dead stroke normal though? Or do others' cars grab close to the top? I'd imagine the dead stroke increased a lot from replacing the one caliper that was sticking and not returning completely.

 

With the caliper replaced and system bled I would expect less than 2" pedal travel, and no mushy feel. If you pump the pedal with the engine running and hold it should not sink further after 1-2 minutes.

 

I just replaced my flexible brake hoses, re-bled the system, and got the 1-2" pedal travel as mentioned by RJ237.
I can measure the exact travel if you wish.

 

Hi nilanium,
I apologise for stating the obvious but you haven't said what sequence you bleed the brakes in,in the past on other cars I always started furthest away from the master cylinder and worked my way back but upon reading the X308 Manual you start from the left front with our cars,

If I hadn't read the manual I'd of started at the back.
Good luck anyway.
Andy

 

Correct way - this aids flushing any air out of the ABS pump if bled dry.
A correctly setup brake system should be less than 2" of travel before brakes are on, literally dab the pedal - hitting the floor is air in the system. The servo takes around a half inch out when the engine is running, you can feel this on the initial depression.

At Eric - did the lines cure the sponge/fade you experienced, and did you go braided?

 

Well, I did not have any problems like sponge feeling or fading, just the LOW BRAKE FLUID once on a downhill run and some heavy braking.

Bought some Dorman hoses as I had other parts from Rockauto.com to order for a friend.
Old front ones were not in the best of shape, I am happy I got 4 new ones, but I still don't exactly know what happened.
Maybe just a tat too low fluid in the reservoir.

 

Hi Sean B,
Was thinking of going braided myself when I put new disc's,caliper's and pad's on,any reason you know not to,I always used them on my motorcycles.
Take Care.
Andy

 

All the R's run braided lines and the Goodridge kits are direct fit for the 8's - for me it's a no brainer Andy, but I drill and wire my brake caliper bolts
Pedal feel is something you notice immediately with braided hoses on these cars Brembo or ATE.

 

I did actually end up bleeding it in the "correct" way as shown in that picture, which seems to be the opposite of traditional bleeding. With the caliper replacement I basically needed to do it that direction.

I considered the goodridge kit, may still get it in the future, but I need to slow down with spending money on this car for a bit.

I'm sure being more thorough with bleeding the new calipers will help, esp. with taking the caliper off and pointing the bleed port upwards. It'll be at least a week or two before I can do that though.

 

You didn’t mention if you replaced pads at the same time?
I wonder if it is just the pads needing to bed in?

 

Excellent, thank you RJ237. I too am suffering from the long travel issue. The local shop could not figure out why the pedal travel remained so long after bleeding and replacing the brake fluid. So, remove and rotate the caliper so the nipple is at the top and bleed . Seems logical, but not always necessary on all vehicles I gather.
Thanks to all, cheers!