R33 GTR mushy brakes

[denisgtr]

Hi all,

So ive deleted the abs off my r33 gtr whilst still using the factory brembos with hfm bm57 brake master cylinder (apparently little better than factory), The brakes before the abs delete were fine and were pulling up well but after deleting abs with nothing else adjusted the pedal got soft and doesn't pull up as good, with first roughly 50% depressing the brake pedal theres no braking what so ever and when brakes do start the pull up its very weak.

so far what ive done:

- new discs and pads

- brake bleed (several times)

- brand new slave cylinder

- braided lines

only thing i can think of i can do is adjust brake pedal rod from the booster.

has anyone had this sort of problem? and im i missing something?

also best way to adjust brake pedal cant seem to find the right info anywhere.

sorry if i worded my problem poorly.

[niZmO_Man]

I bought the same HFM BM57 copy master cylinder and my rear brakes didn't work (reverted back to standard BM50).

So yeah, see if you can put the standard master cylinder back on and test.

[R.3.2.G.T.R]

My builder has used hfm few times and concluded rubbish

[White GTS-T]

Put the genuine BMC back and your problem will go away. Or buy a new genuine N1 item if you want the pedal to be 100%

[robbo_rb180]

Also can tap the 2nd port for the fronts and it works fine as I have done it a few times.

Have tried using a HFM one in the past and could never get it working like a genuine Master Cylinder 2 brake shops had a go with adjusting rods and the pedal.

 

[Djdannyr32]

Have you looked into your brake booster? The unit is a diaphragm and could have a pin hole in it that could cause headaches. 

Just chiming in on my experience with my 32, I was chasing a similar problem for months. Car has Ferrari f40 Brembo's. Bled countless times, Bench bled the BMC, Replaced BMC twice finally using the  hfm bmf57 as well. Adjusted the pedal. Nothing. was borderline dangerous how spongy it was. 

Check the vacuum lines on the booster.

[Dose Pipe Sutututu]

On 18/07/2021 at 4:05 PM, denisgtr said:

hfm bm57 brake master cylinder

here's your problem