Brake fluid change

[TR5tar]

I've read that manufacturers tend to recommend a brake fluid change every couple of years, although I wonder how many of us actually do that. And I've heard that some people just remove some fluid from the reservoir and refill with fresh, rather than purge the fluid completely.

 

My brake fluid hasn't been changed in at least three years, so I thought I'd test it for moisture. It reads less than 1%, so that's good, but the fluid looks quite orange and that makes me wonder if I should change it anyway.

 

What's the view?

 

Cheers, Darren

[Alec Pringle]

Tested with what ?

 

Conductivity meters are, in my experience, worse than useless - every one I've tried has proven ludicrously optimistic when compared to a pukka professional boiling point tester . . . . . which is probably why brake manufacturers do not seem to recommend conductivity testers.

 

Do be cautious Darren - I only test brake fluid with a proper tester, and I've yet to find it lasting any longer than 3 years.

 

Cheers

 

Alec

[John Bracher]

When I got my 6, the fluid looked 'OK-ish', apparently 4 and a bit years old!

 

I had one of our chemists at work test it for water content etc (I forget what else they looked at).

 

It was like weak lager!

Changed the whole lot the next day!!!!!!!

[ChrisR-4A]

I've never gone more than 3 years on my TR without some sort of problem which has required bleeding and as I never re use the purged fluid it all gets replaced anyway,!

Regards Chris

[Waldi]

I part-replace dot 3 or 4 fluid every year, it is a small preventive effort. I just purge each cylinder (wheel) until the fluid gets light color instead of amber.

Two-man ( or in my case me and my wife) job.

I replace no more than 1/2 litre like this each time, and feel it is well worth the effort.

Waldi

[Nigel Triumph]

Change mineral fluid every 2 years, no ifs, no buts. Unless you use silicone fluid but that's a whole new can of worms...

 

 

Nigel

[Lebro]

These were my my findings:

 

http://www.tr-register.co.uk/forums/index.php?/topic/61563-advice-needed-on-changing-brake-fluid/

 

Bob.

[TR5tar]

Thanks for the feedback.

 

Yes, it was a conductivity type tester that I used (similar to the one you have I reckon, Bob). Reading was less than 1%. I wasn't aware of the boiling point tester, but since reading Alec's post I've done a bit of research on them. I can see that it's a more accurate method, but as they cost north of £250, I don't think I'll be buying one soon, as I might as well use the money on changing the fluid. So, question is, do I just remove some of the old from the reservoir as you did Bob, or do the lot?

 

If I do it the way you did Bob, how much can I safely remove from the reservoir? Would I be correct in saying that I have to keep the fluid above a certain level in the reservoir? If so, what would happen if it went below that level?

 

Cheers, Darren

[Lebro]

I removed as much as I could. then re-filled before touching the brake pedal. All was fine.

 

Bob.

[Guest ntc]

http://www.gunson.co.uk/product/G4062

[Waldi]

When I refresh mine, I top up the reservoir first, then after each wheel/cilinder I top the reservoir up again.

I apply the handbrake during the entire job, so more oil flows (per stroke) to the cilinder you are bleeding.

Waldi

[TR5tar]

Thanks all. Purchase made. Glad you suggested that one Neil, as I was already looking at it.

 

So, I know that type of brake fluid has been covered extensively on the forum, but I wonder if there's a way of telling what I have in there at the moment. Any difference in how it looks? I imagine it'll either be DOT 3 or 4.

 

Darren

[Peter Cobbold]

How long does it take for fresh fluid in the m/c to reach the front calipers? Its down there that the water will boil and kill braking effort. There's no fluid circulating - just the same short column moving to and fro along the pipe on each brake application.

Peter

[Lebro]

Be careful with the Gunsons easybleed, unless you can get a perfect seal on the resovoir, you will end up with brake fluid all over the place.

(Ask me how ---- etc.)

 

I have one but now do not use it

 

Bob.

[Guest ntc]

Find a second hand cap

Edited April 29, 2017 by ntc

[TR5tar]

Find a second hand cap

 

Sounds good Neil, but they don't seem that easy to come by. The firms I've looked at only seem to sell the complete reservoir. Anyone know of a firm that would supply just the cap?

[Guest ntc]

Second hand is better but item 3 if stuck https://www.rimmerbros.co.uk/Item--i-GRID600167

[TR5tar]

Thanks Neil.

[Lebro]

It's not the cap on your car that's the problem, when using the easybleed you attach a special (provided in the kit) cap, with a pipe coming out of it.

That pipe then connects to the easybleed bottle, which you have 1/2 - 3/4 filled with fluid. That bottle is then pressurised - usually from a tyre valve

(tyre deflated to some low pressure - cant remember what). The problem is sealing the cap with the pipe onto your resovoir. One small leak & it rapidy fills up, & overflows.

 

Get a perfect seal everywhere, & you will be OK.

 

Bob.

[Guest ntc]

It is always the cap (find an old one if you can) the hole size must be spot on, if you get stuck with it Darren pm me when you get it.

[TR5tar]

It should arrive early next week, so I'll see how I get on with it then, and PM you Neil if I get stuck. Thanks.

[cbxman]

I had a Gunsons easy-bleed many years ago and used it quite often. Then one day it exploded with fluid going everywhere.. What a mess. The plastic seemed to have become very brittle and I'm not sure why. I had to hose everything down with water as fast as I could! Needless to say I don't use one any more.

 

I now use the vacuum type which pulls the fluid through via the slave cylinder bleed nipple. The main down side is having to own a compressor to create the vacuum. If you have a compressor....use the vacuum type.

 

My 2.5p worth.

 

Jerry

[Lebro]

This may be a silly question, but how do you create a vacuum with a compressor ?

Bob.

[Waldi]

With a venturi.

[Lebro]

Ahh, I see