<VV> Blocked brake hose

Mon Oct 16 13:18:05 EDT 2017

### Yes indeed! If they had fitted the wheel cylinders the other way up 
it would have been a lot easier. Like a lot of things however, once you 
know what you're up against it's not too bad.
I will try that pressure test on the brake lines - as I said in another 
post, this is not something I've encountered before - being originally 
from the UK (now in Florida) the salt always eats steel brake pipes from 
the outside before they can corrode from the inside.
I have heard of flexible hoses blocking or acting as one-way valves 
before - usually this makes the brakes lock on - mine was the other way 
around.
This never used to be a problem - I think it co-incided with 
manufacturers changing to a new type of non-porous hoses - they 
suspected the earlier ones would let water in.
Another thing to be careful of if you're keeping the old master 
cylinder is never to push the pedal all the way down when bleeding - if 
you do, the piston will be in parts of the bore that it's never seen 
before, and there might be some corrosion in there that will damage the 
seal.
Incidentally, for quickness I got brake shoes and hoses from Autozone 
across the street from me. I'm amazed that I could order parts for a car 
that's been out of production for fifty years at 8.00 on a Saturday 
evening and I'd have them by Sunday afternoon - you don't get that kind 
of service in the UK! They didn't list the cylinders so I got them 
shipped down from Clarks, equally fast but UPS overnight was expensive!

On 2017-10-16 09:35, Seth Emerson wrote:
> Way to go, Hugo! Sometimes, when you are working on these old cars,
> you wonder "What was going through the mind of the engineer, example,
> to hide the bolts?" On the hoses, as the cars pass 50 years, it pays
> dividends to explore further - beyond outside looks. Hoses are
> relatively cheap (sorry about your shipping costs) as a replacement.
> Be sure to examine the steel tubes carefully. They can rust from the
> inside out. The final check will be the hard-harder brake test. It 
> may
> sound counter-intuitive, but after you are finished, with the wheels
> on and brakes bled, you sit in the drivers seat and push the brake
> pedal really hard, like a truck had just pulled out in front of you.
> Then push harder, as hard as your leg can push, just for a moment.
> This serves as a final test of whether or not you can trust the 
> brakes
> in a similar situation, when that stupid truck really does pull out 
> in
> front of you. The instant adrenaline will power your leg to amazing
> feats. This "hard-harder" brake test is routinely performed at
> Autocross events, as a verification of competitors brakes, before
> participation. In many years of sitting in peoples cars and 
> performing
> this test, I have personally blown out two brake systems. Both
> competitors fixed their cars and competed in the events, and both
> thanked me for showing them the problem. Better to find the problem
> there, than in front of an on-coming truck. Oh, and remember to clean
> up that brake fluid, it will eat up paint!
>
> Seth Emerson
>
> -----Original Message-----
>  From: Hugo Miller via VirtualVairs <virtualvairs at corvair.org>
>  To: virtualvairs <virtualvairs at corvair.org>
>  Sent: Mon, Oct 16, 2017 6:32 am
>  Subject: <VV> Blocked brake hose
>
>  Just doing a brake overhaul on a 1964 convertible I just bought, I
>  found both rear wheel cylinders leaking. Only done the right one so
> far.
>  There was so much crud in the cylinder I decided to flush out the
> brake
>  lines - probably still got the original brake fluid in there! Put an
>
>  air-line on the pipe from the master cylinder, & nothing would come
> out
>  the back. I could blow from the back to the front (& fill the trunk
> with
>  dirty fluid!) but nothing from front to back. Flexible hose was
> acting
>  as a very efficient one-way valve.
>  Incidentally it took me a while (and a search on Google!) to figure
> out
>  how to get the cylinder off - I ended up removing three of the nuts
> that
>  hold the drive shaft to the backplate, & undoing the fourth to the
> end
>  of its thread. That enabled me to pull the axle shaft out just
> enough to
>  get a 3/8" wrench on those little fixing bolts.
>  One down one to go!
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