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Re: [T3] Brakes done! Lessons learned...

On 22 Jun 2005 at 21:02, Nico teWinkel wrote:

> I'd still be wanting to replace the metal lines just because of the amount 
> of rust on the ends. The LF line was seized to the LF hose, and I couldn't 
> separate them even after I had it out of the car. Other ends were rusted 
> onto the lines themselves and would not turn.

Interesting. I've never seen one that I couldn't get apart. The usual stumbling 
block is the hard line that is frozen to its line nut so that you are in danger 
of twisting and breaking the line. I sometimes have to work at it to avoid this 
problem, but I've always managed to get it loose and save the line. The 
motivation for me has usually been that I have a stock of all the usual 
cylinders, but only an odd assortment of used hard lines, so I don't want to be 
stuck in the middle of the job scrambling for a part that I don't have on hand.

> My wheel cylinders definately needed replacing or 
> rebuilding (one was leaking, the other had a seized bleeder valve)

Wheel cylinders are easily honed and rebuilt right on the car, and I always 
just clean up and reuse all the original innards with no problems. The bleed 
valve is more of a problem. I can always get these apart if I take them off the 
car, but that's certainly more work.

> > even here in the rust belt I have seldom replaced any hard line other than 
> > the center one.
> Oddly enough, that was the one line I felt I should have left, as it looked 
> to be near-perfect inside and out, and was the most painful to replace.

Yes, that is odd. I agree that replacing this line is one of those jobs that I 
REALLY hate. When I've ordered stainless replacement lines for these I order 
them about 3" longer than the ones that all the vendors carry. That helps some, 
but there's no way to make this job easy.

> I bought the Varga with double bleeder valve (so the left one is same as the 
> right one). My braking is so much better than it was before that I wouldn't 
> know the difference I guess.

The double bleed valves are a real advantage. This means that you can bleed air 
off the top and DoT-3/4 off the bottom in a few weeks just to make sure that 
you got it all out.

> What makes the OE ones work so much better?

They have cutouts in the pistons which keep the pads from wearing wedge shaped, 
because the motion of the rotor tends to pull the pad off to one side. 

They have 42mm pistons instead of 40mm pistons. The braking force is 
proportional to the piston AREA, which is proportional to the square of the 
diameter, so the 42mm pistons give 10.25% more braking force for the same pedal 
pressure. Of course you can up the pedal force, but it's really the F/R braking 
balance that you've upset.

> Ah, I fell for that "rubber hoses can stretch so you get firmer brakes" 
> line.
> Rubber hoses are cheaper indeed ($10 instead of $15 each), and it looks like 
> you can get all the right pieces easily at CalImports - I had trouble 
> finding the 11" M-F in SS.

Both have some resilience, and the SST ones are probably stiffer, but there is 
still room in those where the Teflon has to expand to meet the SST braid before 
the braid tightens and stiffens. All in all there's little left that you would 
be likely to notice.

BTW, if you like a really firm pedal, you would like calipers which are frozen. 
Those will give the firmest pedal, since the pads are not allowed to back away 
from the rotor. I find that my customers often complain about a soft pedal 
after a complete brake overhaul, and they're right. The problem is that they've 
gotten used to the abnormally high, firm pedal that they used to have, which 
wore out pads and kept the rotors scorching hot.

> With hindsight, yes I would have bought the rubber hoses especially 
> considering that they brake the same and are more original looking too.
> Nowhere do they mention that they are not Dot approved, which ticks me 
> off... they make them sound better.

In reality, they probably are actually better; they just haven't bothered to 
apply for the DoT certification. I have no idea what this certification 
consists of, but my impression was that sales of items like this usually came 
with a "For off-road use only" disclaimer simply because of this lack of 

When I say "better" I'm going out on a limb and guessing that they might 
actually last longer, but OE rubber lines last on the order of 30-40 years, so 
I don't think there's much advantage here.

> Have you ever seen a rubber hose fail ?

One of my originals on my 69 started to leak on the way back from Parma. That's 
the only leak I've ever had. I've seen one which burst on a friend's '66, but 
that was years ago and I don't know the circumstances. It's possible that he 
installed it with a nasty twist in it.

It's rather common for them to develop some sort of internal problem, however, 
that lets fluid thru to the wheel but then won't let it back. They start to act 
like sort of a check valve and this is the most common reason for replacement. 
I'm guessing that the Teflon/SST lines won't ever suffer from this problem, but 
30 years is a lot of time for unexpected problems to pop up.

> > It's very good to keep those [bleeder valve] caps on there. I thought new 
> > parts always came with them....
> Maybe they forgot...

I'd love to find a source for the ATe bleed valve caps at a reasonable price. I 
used to see these for $0.25 each, but now VW sells them for over $1, and they 
aren't even the right style. I can buy rear bleed valves w/caps for about $1 
each, but I use the caps with the bleeders.

I'm pretty much resigned to stealing caps from cars in the junk yard these 

Does anyone else have a source?

> >> 1 small bottle of alcohol to rinse reservoir and connector hoses after
> >> rinsing with water.
> >
> > Just make SURE that all of this has COMPLETELY evaporated before you add
> > anything else to the system. It's hard to be sure that the inside of a 
> > tube is dry.
> I left it open in my garage for at least 2 days, so I hope that did it.
> I had thought of tossing some fluid through it, but didn't - do you think 
> that would have helped?

Following the water with alcohol was a very good thing to do, just because they 
mix well and alcohol is very volatile. If you could have followed this by 
blowing them out with air that would have been better, but if you hung them up 
vertically, so they would drain, you're probaby fine.

Most of the black stuff that comes out of there is actually just rubber wear 
particles from the MC seals. It look worse than it really is.

Jim Adney
Madison, WI 53711-3054

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