Hi guys,

Having problem with 2001 Beetle. Have just replaced all brake pads and
front discs and replaced brake fluid. Noticed brakes were really spongy
so bled fluid and replaced again but still have same problem. Is this
likely to be air in master cylinder? Pretty sure there is no air in
rest of system having repeated bleed

With ignition off brake pedal is solid, but as soon as engine is
started, pedal becomes very spongy.

Any suggestions on how to remedy this? Is it possible to bleed master
cylinder? Noticed there are 2 bleed valves on top of cylinder so can
this be done without removing from car?

"Stevo" <steven.x.hunter (AT) googlemail (DOT) com> wrote

Is it any worse-spongy or the same-as-before-spongy? VW brakes IMHO are
usually softer and with more travel than most cars. It could be just how
they are.

that's typical of any power-assist brake system due to the lack of engine
vacuum for boost when the engine isn't running.

Pedal is definitely lighter than before having to press almost to the
floor to get the thing to stop! I'm pretty sure there's no air in
brake lines having bled through about 2 litres of DOT4 and it's not
leaking flud anywhere. I'm suspicious about master cylinder though as
may have let fluid level drop too low during first bleeding. Would
have thought that repeating bleed process would have resolved that
though. Have driven the car for a couple of miles but the problem
didn't improve. Do I just need to keep driving and see if it sorts
itself out?

Matt B. wrote:

"Stevo" <steven.x.hunter (AT) googlemail (DOT) com> wrote

well it could be air in the M/C, yes, if you let it get too low during the
first bleed, but yeah the repeat bleeds should fix that.

However did you use a vacuum bleeder or a pressure bleeder or did you just
bleed it w/the brake pedal? If you did the brake pedal and you pushed the
pedal more than just the usual length of travel, you may have destroyed the
inner M/C seals. Even when bleeding you shouldn't overrun the normal pedal
travel range or the seals can get damaged and as a result it might be
leaking internally. In other words, fluid isn't leaking out, but it's
leaking past the piston such that you aren't really compressing just the
fluid anymore...you're just "squeezing" the fluid around inside the cylinder
from one part to another. If this is the case, it's new M/C time.

"Carlton" <carlton (AT) noppernm19 (DOT) net> wrote

Is that the stuff that comes in the Czech cut-crystal decanters with the
certificate of vintage?

Bill Longyard

Some have suggested that pressure bleeding works better than the old
fashion pump and open bleed screws I grew up doing. If the master
cylinder has some issues like rust you may have goofed up the seals
and the master cylinder is leaking internally. If your Beetle is
similar to my 2003 Jetta there should not be any mushyness or
significant travel.

No, driving a car with bad brakes does not fix bad brakes. Unless of
course you total the car because you cannot stop.

On 8 Oct 2006 10:48:24 -0700, "Stevo" <steven.x.hunter (AT) googlemail (DOT) com>
wrote: