[TR] Brake fluid for Triumph

[glemon at neb.rr.com]

I used Castrol LMA for years and seemed like every year or so, sometimes more, sometimes less, some master or slave cylinder would fail.  I didn't really keep track of the timeframe, but seemed like a very regular basis, often a rear wheel cylinder.

Sometime ago I switched to Dot 5, actually bought a car that had it.  After sometime (nearly 20 years of ownership) it dawned on me that I hardly ever had any problems with hydraulics anymore.  I was a firm believer in the benefits of Dot 5.

Chapter 3-Last year my relatively new (7 years from the restoration, which is some time, but I was getting used to having so few problems it still surprised me) brake master cylinder quit, followed by a leaky clutch master.  Inspection of the brake master shows corrossion at the bottom of the bore, as if water had settled there.  

So Dot 5 seems to work well with hydraulics, but even though it does not absorb water, if water gets into the system, which apparently it can, it can do as much or more damage than it can in coventional fluid.

My fault for not flushing the fluid more often, but a little unsure if a flush would get lingering fluid out of the bottom of the bore (vs. a conventional flush which will displace fluid with x %age of water with new fluid with < x %age of water, thereby lowering water in the system and making your fluid good again).

YMMV, everybody seems to have different stories and experience with brake fluid, but that has been mine.

Greg Lemon
TR250

---- ptegler at verizon.net wrote: 
> ..the only negative I've ever encountered with Dot 5 in our old cars is it does not lubricate the rubber as well as older fluids.
> Synth and natural rubber also react differently ...as with everything with LBC's...   ymmv
> 
> ptegler
> 
> 
> -----Original Message-----
> From: TERRY SMITH <terryrs at comcast.net>
> To: Randall <TR3driver at ca.rr.com>; Sujit Roy <triumphstag at gmail.com>
> Cc: Triumphs <triumphs at autox.team.net>
> Sent: Thu, Nov 29, 2018 11:07 am
> Subject: Re: [TR] Brake fluid for Triumph
> 
> When restoring my 3A in 2002, while the body was off the frame I replaced all the brake lines and hydraulic cylinders.  I learned about Dot 5 silicone based fluid from the List then and went with it. After 15 years of driving, the same brake system remains rock solid plus I never blistered paint with the occasional spill.  Doesn't silicone wear easier on rubber seals?
> 
> Terry Smith, '59 TR3A  TS 58667
> New Hampshire, where early snows have sent both bears and Triumphs off to the Land of Nod 
> 
> 
> > On November 28, 2018 at 7:58 PM Randall <TR3driver at ca.rr.com> wrote:
> > 
> > 
> > 
> > > Can I use DOT 5 in the Stag? Do I need to flush out the 
> > > current DOT 3/ 4?
> > 
> > Both of my Stags have DOT 5 in them.  LE1473 was converted just by bleeding
> > through at each corner until clean purple fluid appeared.  The other one
> > (dubbed Frankenstag because it appears to be parts from at least 3 different
> > cars) had a failed MC and stuck rear wheel cylinders when I got it, so those
> > were repaired at the same time.
> > 
> > However, LE1473 already had what seemed to be a minor master cylinder
> > problem before the conversion (pedal would sometimes drop towards floor
> > while sitting at a stop light), and it suddenly got a whole lot worse not
> > long after the conversion (no hydraulic brakes at all).  (I also learned
> > that the back brakes on a Stag are more prone to fade than a TR3.)
> > Post-mortem showed both MC piston seals torn, and approximately the
> > consistency of Gummi Bears.
> > 
> > So I'd have to say that "best practice" is probably to replace the seals at
> > the same time.
> > 
> > Randall
> > 
> > ** triumphs at autox.team.net **
> > 
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