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Triumph TR3 - So much brake little time

Having just purchased my '57 seems like I have lots of being.
What kind of brake fluid to use? I've asked around here and there and I'm getting different oppinions.
DOT 3?....Dot5?...Silicone?
Moss Motors advertizes a brake fluid that is good for all Triumphs...all years.
Any suggestions?
Also, not knowing what is in there now...Can I just bleed the old stuff out and start anew?

Although I have been up to this point, a dyed in the wool DOT 4 guy, I'm starting to turn the corner to DOT 5. Silicone fluid is probably the best way to go.

You do have to replace all the seals and at least flush the lines to remove all the old fluid. The 2 don't mix. But after you do it, you will probably never have to change anything on the brakes again. This is an important consideration, as the rear shoes are hard to come by and not cheap to reline. And the cylinders will freeze up if not used too much.

I've seen so many positive responses from people using DOT 5 (silicone) fluid, that I am convinced I've been stupid for hanging on to the DOT 4 all these years.

The real clincher here is that DOT 5 does not eat paint. When your master cylinders leak, the new paint under them will not blister like a bad sunburn.

DOT 5 was developed for vehicles that don't get frequent use, like National Guard trucks for example. It works, from everything I've read. Regular fluid is hygroscopic (absorbs water), which is a good thing until it can't absorb any more. Silicone fluid has a quirk in that it holds bubbles of air in suspension more easily, so don't shake it up before you put it in.

The old hands on these BB's get tired of hearing about brake fluid, because it causes arguments. I've read a ton of them, and like I said above, think I've been crazy for being so stubborn to stay with the Castrol LMA (low moisture absorption) fluid that's recommended in old manuals for the cars.

If you're wanting to be old school, use DOT 4. If you want to have less trouble, rebuild and clean well. Then use DOT 5. (Not 5.5 by the way, that's not silicone.) And definitely not DOT 3 for any reason!!!

That was pretty thorough Tom. Even for these old ears. 'Nuff said. DOT 5 it will be.
Thankyou so much
PS. Looks like I'll have to drive it home in the family car, and not the TR. Don't want
Thanks for that warning too.

Have fun, Charlie.

The last fluid I bought was Valvoline DOT4. It hasn't given me any problems yet. But if I ever get up the gumption to flush and rebuild totally, it's gonna be DOT5.

I'm 53, had a TR3 since 1970. Don Elliot bought his brand new. There's a TR4 about 25 miles away from me that a guy saved from the crusher. Wish I had a place for it. $200. Maybe I'll get the drivetrain. It would be nice to have a synchro 1st gear.

I use DOT 5 in all my rebuilds anymore for the above reasons. Not to be confused with 5.1, which is compatible with 3 and 4 but still is a paint eater.
This will bite me in the butt somewhen, but I never replace the calipers when converting to DOT 5; just drain the system and go with the new 5.

Rebuilding the calipers is a time consuming process. And a bit expensive. Has anyone used the new anodised aluminum caliper pistons? They are cheaper.

This thread was discussed between 07/07/2006 and 13/07/2006

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