My '05 brakes are acting strange.
During moderate to heavy braking my brake pedal suddenly drops a few inches.
Not to the floor but it sure gets your attention.
They are a little spongy and have been getting progressively worse.
I use ATE fluid with speed bleeders and have ss. lines and a brace for the m/c.
Considering buying a new m/c and booster

 

It seems you've well assured the lines are bled, and already have SS lines, so it's possible the cylinder seals are going bad and partially leaking by on hard pressure.

 

Did you bleed them recently?

 

Yes I have bleed them recently
and even used the two man method of pump an hold.

 

Did you also try bleeding the M/C?
I know... people will say you don't have to and will point out that later models don't even have the option, but I experienced the same thing after bleeding my brakes too.
After I bled the M/C it worked fine... so now I add that to my "bleeding steps".
Its the easiest thing to bleed... so why not just do it!
The order I bleed is M/C -> RR -> LR -> RF -> LF -> M/C
To each their own

 

Did you do a complete drain or were you flushing as you were bleeding?

Sounds like you still have air in the M/C or ABS Unit

 

LOL A little preemptively defensive there Jon. Yeah, no harm in bleeding the m/c if you have the option (even tho' you don't have to).

 

do not have a bleed screw in my '05
will buy a '04 m/c with that feature
i did not drain the entire system or run the reservior dry
you are right it sounds like air in the abs or m/c

 

booster and master

 

Hey Eric,
I am just waiting on pay day
The booster looks like it would be a pia to get to fasteners under the dash
See you at VIR