456 Brake Bleeding

Dean- Brake and clutch share the same reservoir. Are you getting air from the clutch? Need to bleed both?

Taz
Terry Phillips

 

you are going to have to bled the crap out of it now. rear lines are very long compared to front. Try bleeding front first about 6 open/close cycles (my guess) of the bleed screw and maybe you'll get air out. Then if you do you will know you need many more like double to get the air to make its way to the rear. Key-on and cycle the abs pump. let it charge up and fully pressurize the system as you bled. when the pump stops bleed when it come on stop and let it come up to pressure. If you really screwed it up then you will have to bleed the master before you bleed the lines. Clutch should be ok if you let air get to the top of the clutch inlet side as long as you did not push the clutch in while the fluid was down below the inlet. There are other tricks if this does not work. Keep us posted.

 

Bleed the master cylinder.

 

Could you please clarify? I am going through this process right now (front circuit only). Do you bleed with the ABS system running (once fully primed) or do you turn the power off and do the bleeding after you've turned the power off (presuming that the system pressurized itself). Thanks for the advice!

 

Since there's a baffle in the reservoir theclutch functionality is not affected if you drain the brake fluid, or vise versa. The clutch reservoir, which is surrounded by the outboard of the two brake reservoirs, is actually connected to the inboard reservoir.

Bleeding of the brake system is much quicker if you slightly pressurize the brake reservoir. I connected a piece of bicycle inner tube around the filler opening of the reservoir, and the other end connected to the compressor, blowing the tyre up a bit. This gave enough pressure to quickly blow any air from the system just by opening the nipples at the calipers. Beware not to overdo the draining and keep enough oil in the reservoir.

 

Thanks @franschman !! Do you recommend a certain PSI (air pressure in PSI or metric) of air to inflate to? Thanks, -w

 

Around 1.5 bar / 20 psi maximum is what most pressure bleeders recommend. (You can buy a pressure bleeder if you don't want to concoct you own from bicycle bits.)

 

I used much less pressure. Maybe 0,1 or so Bar. Just enough to inflate a piece of inner tube a bit.

 

Update: bled the brakes profusely using multiple priming of the ABS pump, bleeding the lines properly at the calipers, and further pumping the pedal to further prime the pump (while running) and then bleeding further at calipers. Results; clear fluid, no bubbles, hard pedal.

Took a test drive around the block a few times and did about six HARD stops and the ABS engaged properly and no warning lights each time.

BIG QUESTION: if the car is sitting/idling (running) and I then pump the brake pedal rapidly 10 times (or more) in a row, the "Brake Warning" light comes on for 2 seconds and then goes out. Is this normal? The car was doing this before I test drove it and also after (but only when rapidly pumping the pedal).

I never tried this in the past before my recent ABS pump failure (obviously, I had no reason to look for such a warning lamp). Methinks this is normal cautionary flash of lamp or because I switched to the TEVES Jag pump unit maybe the sensor is reading that pump model differently? ...I did use the Ferrari pressure switch and the Ferrari accumulator (but switched over to the Jag pump body). Thanks, wp