scamsel

had a question............when coming to a hard stop and downshifting using engine braking, is it normal to have the brake pedal feel like it loses pressure to where the brake pedal pushes down further towards the floor for a split second?

was wondering, does anyone get what i am describing and/or know what causes that to occur?


thanks!

LexyISF

Yes your brake pedal will modulate when braking hard. ABS etc.....

scamsel

thats not really what i'm referring to though. i meant specifically during engine braking while the brake pedal is firmly pressed

caveman

so you're saying while firmly pressed, the brake pedal will sink down momentarily and then firm back up again?

itsmike177

iTrader: (3)

No, that should never happen in a healthy braking system. Owned 2 ISFs and never had the pedal "sink" down while downshifting when coming to a very hard stop.

Maybe you have air in your lines, maybe a brake fluid bleed/flush?

scamsel

thx mike, i guess i'll get it checked out, but just to confirm....i'm speaking about when in manual and sport mode. it doesn't do it just when applying heavy braking solely from applying the brake pedal (where the car just downshifts on its own accord).

rather, its only when manually downshift through a couple gears, inducing some engine braking (as the car kicks up the rpm's to rev match) at the same time as i am applying the brake pedal.

itsmike177

iTrader: (3)

Yes, M + sports mode, revmatching downshifting while braking hard (rpms at 5000+ when downshifting to the lower gear), pedal should not sink down in any car. Mine never did.

lobuxracer

iTrader: (2)

I would have noticed that for sure. It's never happened in my car.

I8ABMR

I have done three track days with mine and never noticed anything like that and I compression brake on almost every corner and apply the brakes harder then anyone on the streets

lobuxracer

iTrader: (2)

What he said, but more track weekends.

scamsel

cool thanks again all. the 2 i was hoping would reply did, ha. i'll check it out, see if a brake fluid flush does anything