MastCylinder help!!

[justaZcarguy]

Ok, I have a trip coming up to Bend, Or. The master cylinder in my '71 is only operating the front brakes at this point....

At the bleeders on the master cylinder there is just no pressure to the back brakes, but plenty to the front.

I have my '73 car, but the master cylinder is different, the resivors are reversed.

Dose anyone know if I can switch the master cylinders over if I switch the plumbing as well? The '73 car has great braking...

Thanks for the help, I can get a master cylinder for $48. It's just $ are tight and I'm weighing all my options before I part with the $$$.

Thanks all, I appreciate it, I need to do this today as I leave in the morning and will have to battle the snowy passes.

Have a great weekend!

Brian

[Bambikiller240]

Originally posted by justaZcarguy

I have my '73 car, but the master cylinder is different, the resivors are reversed.

Dose anyone know if I can switch the master cylinders over if I switch the plumbing as well? The '73 car has great braking...

Brian

YES, If you switch the lines AND the Master from your 73 to the 71, everything will be fine The Larger res is for the disc brake calipers which require more fluid to operate. You must switch the lines AND the Master. Don't get it hooked up backwards or you'll get a nasty surprise when you least need it (when you MOST need your brakes!).

[justaZcarguy]

Thanks Carl,

I have swiched everything over, the funny thing is, I hear just a slight hiss of air towards the end of the pedal throw...

The pedal is still going to the floor, granted that I have not bled the brakes yet but the air noise is still bugging me.

I was told that there is a valve that releases the air pressure from the chamber when it gets to a certain pressure...

I have never heard of this...

Anyway, the car seems to stop better, rear seems operational...

And this is before the bleeding, so hopefully the pedal will improve with the bleed...

Brian

[Bambikiller240]

The air hissing sound that you hear is from the brake booster which is vacuum operated. It is normal to hear that with the pedal moving so far as it is with the system un-bled. Do a proper bleed of the system starting with the Master Cylinder itself, then moving to the wheel cylinders starting with the Right Rear, then Left Rear, then Right Front, then lastly Left Front. You should be good to go!

[justaZcarguy]

Thanks again Carl!