<VV> Breaker Brake

[Bill Elliott]

Despite your obvious bias (VBG) you have laid out a very decent summary of the various benefits and 
weaknesses.

The only additions I would make are that some DOT 4 fluids (like Castrol GT/LMA) and all DOT5.1's (that 
I'm aware of) have dramatically lower moisture absorption characteristics than DOT 3 and most DOT 
4's... so while they still "distribute" water once it's in, they don't as aggressively attract it, making them 
more like DOT5 in that regard.

And from what I can tell, cars with real rubber components (which reacted with some DOT4 fluid other 
than Castrol) do not have the same reactions with 5.1. I'm using it in quite a few old Brit cars with rubber 
components where I would not dare use non-Castrol DOT4..

Lots and lots of collector vehicles use DOT5 for the exact same reasons that you do... and those are 
very valid reasons.  And as long as you do everything right (keep everything adjusted properly, etc) and 
don't overheat the wheel cylinders, it usually works just fine. 

As I mentioned, I still have DOT5 in some of my cars (actually down to just 1 now) where I'm willing to live 
with those limitations. 

And those that have seen my cars know I'm not going to worry about brake fluid damaging my paint! ;-)

Bill





>Wow, I'm sure glad to learn that the dozen or so vehicles that I've  
>successfully converted to silicone brake fluid couldn't possibly work.  I'm  also 
>delighted to know about the higher boiling point of DOT 5.1 so now I know I  can 
>have this *useful* benefit of DOT 5 silicone and get back the beloved  
>corrosion and paint-damage characteristics of the beloved DOT 3 fluid.
> 
>DOT 3 Benefits: Cheap, distributes moisture
>DOT 3 Weaknesses: low boiling point, permits corrosion, damages paint
> 
>DOT 4 Benefits: Moderate price, distributes moisture, higher boiling  point
>DOT 4 Weaknesses: permits corrosion, damages paint, some rubbers react to  
>chemistry
> 
>DOT 5 Benefits: High boiling point, won't damage paint, dramatically  reduces 
>corrosion
>DOT 5 Weaknesses: High cost, coalesced water in system may boil,  entrained 
>air may cause "spongy" pedal, system rubber should be new upon  conversion, 
> 
>DOT 5.1 (See DOT 4) + high boiling point
> 
>Pick which benefits are important to you and select accordingly.  For  me, 
>the lack of paint damage and corrosion reduction leads me to DOT 5.   What's 
>your choice?
>Craig Nicol
>