I am not seeing any fluid leaking from the PDWA.
I am getting fluid at all four corners when bleeding.
The MC is new from Spit Bits - $199. I am using the Castrol GTLMA fluid they sent me.
I have not thoroughly checked for system leaks, but the fluid level in the MC doesn't appear to be dropping.
--Previous Message--
: The PDWA is an "H" in the
: system where the branch connecting the
: two uprights is a piston that toggles a
: switch when there is leakage out of one
: side of the system or the other. There
: is no "fluid" connection
: between the two uprights... only the
: mechanical switch piston. So... it is
: unlikely that the PDWA is causing your
: car's braking problem. However, if you
: see fluid oozing out of the PDWA
: (mainly at the switch) then obviously
: that's a problem.
:
: Our '72 Spitfire should have a nearly
: identical brake MC. I did not bench
: bleed the MC when I installed it (new,
: not rebuilt). If you are able to get
: fluid out of the bleed nipples at all 4
: corners, the MC would appear to be
: primed adequately.
:
: The part of your post that caught my
: attention was the part where you said
: the pedal would sink to the floor. If
: the fluid level in the reservoir is not
: dropping, that sinking pedal suggests
: fluid getting around the seals in the
: MC. Is this a rebuilt, NOS, or new MC?
:
: I was annoyed when we bought the
: expensive MC for the Spitfire because
: it came with a warning not to use DOT-5
: fluid and... it leaked between the
: plastic reservoir and the metal
: cylinder housing. I let the vendor
: know and their reply bothered me even
: more. They said that they didn't have
: too many complaints about brake master
: cylinders... maybe "only 5%".
: I don't believe I am unique in
: thinking 5% is too high a complaint
: level on a safety related component.
:
: Doug L.
:
:
: --Previous Message--
: I recently replaced my original brake
: master cylinder with a new unit. I did
: not bench bleed the MC - a number of
: people told me any air should bleed out
: by the normal method with enough
: patience. I was able to get a firm
: pedal after several thorough bleedings
: of the system. Driving the car about 30
: miles I felt like the pedal was
: sometimes a tiny bit soft, but on any
: second tap of the pedal it firmed up.
: The next time I tried to drive the car
: the pedal went straight to the floor. I
: bled the system again, but no luck. If
: I push hard on the pedal it has some
: feel, but usually slowly goes to the
: floor. If I push gently it goes
: straight down. Does this all suggest a
: bad MC? There is no fluid leaking from
: the plunger end of the MC. The car does
: have the PDWA. It was replaced about 15
: years ago. Can the PDWA cause issues
: like this? Or should I go back and
: bench bleed the MC? Any advice would be
: gratefully received.
:
:
:
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