[Spridgets] brake bleeding problems

[Brad Fornal]

What is the condition of your rubber flex hoses at the front? Could
they be old, and collapsing internally? This is a common ailment when
the old hoses begin to fail.

Brad

On 7/30/07, Marc <smarc at smarc.net> wrote:
> Ok, getting somewhat aggravated here, this shouldn't be so difficult...
>
> 73 midget, complete brake job, all three hoses, new wheel cylinders,
> rebuilt calipers, brand new lockheed master. Castrol  LMA fluid.
>
> Using a long piece of tubing running from bleeder back to master, and
> starting from the longest run to the shortest, bled the system till no
> more air bubbles could be seen anywhere. Seemed good with a nice firm
> pedal. Car is still on stands, so cant drive it yet. Notice the front
> hubs seem locked, can't budge them by hand. Hmmm says I, let me crack
> the bleeders on the front and see what happens.
>
> Cracked them just the slightest bit, and  the front hubs freed right up.
> Once again brake pedal hits the floor with no resistance. Back to where
> I started -WTH?! 2 - 3 pumps builds up system pressure again, but it
> "just disappears" within moments, pedal will go to the floor. No fluid
> leaking, and had good fluid flow from each wheel (as determined by
> bleeding).
>
> This isn't the first time I have done this job (albeit previously on
> MGB's). Never had any probs like this. What is going on here?
>
> Have gone around multiple times tapping on lines & fittings to remove
> trapped air. Have bled using conventional method. Have bled by pump
> pedal several times to build pressure, then crack bleeder (closing it
> while pedal is held down of course).
>
> Have checked the differential pressure warning switch - it is centered
> and working. No, I did not bench bleed the master as I had no fittings
> which would work with it.  My uneducated guess is that bleeding using
> the tubing as I did is pretty much like bench bleeding? We continued to
> circulate the fluid for a few minutes after the bubbles had disappeared
> thru the entire 12 - 14 feet of tubing... Could there be that much more
> air lurking in the system?