[alfa] 105 Benditalia Brake Boosters

[alfacybersite <acs@xxxxxxxxxxxxxxxxx>]

" Hello Biba. I also have had a problem with a '69 brake system. The
 symptom was rather severe. About the third time I would apply the
brakes, they would lock up and only release after a while. I have
 temporarily disconnected the vacuum hose which removes the symptoms,
 but makes braking a little more difficult, but not impossible. Any
 advice would be appreciated." Bruce SharerRaleigh, NC

 ******

 I received the following inquiry off digest, but doubt if Bruce will
mind if I answer it 'out loud'.

Actually I've driven a '69 Spider with boosters / servos completely
removed and didn't feel the braking was all that bad - except it isn't
original and it is more of an effort.

The absolute killer for these cars is to not to be driven for long
periods of time and not to change brake fluid regularly. 

I'd give a 75% guarantee (money not refundable) that the entire problem
with the sticking front brakes is the plunger valve and seal / cup are
somewhat or completely  frozen. They are  located (with boosters 
removed and turned upside down) directly below the small diaphragm &
spindle's housing. The spindle actuates the plunger valve. 

Often they are extremely difficult to remove but persevere. You will
reuse the plunger valve, but the seal / cup will come with the small
diaphragm kit. Because of its makeup, it is difficult to know if the
small diaphragm's outer housing's filter is plugged up and makes the
situation worse. Should it, the new housing will resolve the issue.

As long as the boosters are off, I'd remove the retaining band on the
large diaphragm. Be a little ginger in there is a large spring behind
the diaphragm, but can be fairly easily held back by hand. The main guts
won't spill out since they're held in by a circlip.  If there is brake
fluid in the diaphragm housing, then you'll also need two of the large
diaphragm kits. 

Most likely this has nothing to do with sticking brakes, but again if
a'69  Round-Tail, especially, has sat for long periods of time, I'd
remove the rear brake bias unit and disassemble. You won't enjoy this
either, but will give you a chance to clean out the jello like gunk.
Don't believe seals are available for it.

After reassembling the boosters and bleeding the brakes and before going
for a test drive, grab an old blanket / towel, your 7 and just in case 9
mm wrenches along with some rags. One can always crawl under the car and
release the brakes by undoing the bleed screws. True, they might begin
to lock up again before you get home, but you should at least get home. 

Remember, I only gave a 75% guarantee. 

Biba
Irwindale, CA USA
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