brakes (1 Viewer)

[dave newell]

Correct. IMHO. modern Dot.4 fluid is good for a lot longer. Just keep your eye on it.

Can you "see" the degradation of brake fluid through moisture takeup with the naked eye? I use a tester to establish the water content and its much more reliable than my "eye". ;-)

D.

 

[PeteH]

I Knew about Brake fluid being Hygroscopic. So I changed it (had it changed) when the disks all round where replaced. (6.4 GM pusher Diesel R-V). Two years later on the old A18 heading towards Brigg. Fairly slight but significant hill with a bit of a bend in the bottom. I says to herself Hmmm? No Brakes!!!. Fishtailed it to the bottom Into a Bus Bay pumping the pedal like a madman and jammed it against the kerb. Phew!!! Quick look in the CCC book and the local Pub is also a CL. Upshot was I spent the weekend on the site with her indoors pumping the brake pedal and put over 5 litre Through the system. This thread has just reminded me to look at the "new" Mo Ho and maybe "do" that, (8yrs). Strangely ALL my past Classic cars and a BMW Bike, have been uprated to silicone fluid when the Brake system(s) where refurbished, as silicone fluid is not hygroscopic. But I am nervous about doing it without replacing the seals etc; in case it is not compatible.

Pete

 

[dave newell]

Upgrading to silicone fluid is generally not recommended without replacement of all seals in the system. Sad really that motor manufacturers don't install it as standard as its:
1/ Non hygroscopic so doesn't attract moisture out of the air, in fact silicone is repellant to moisture.
2/ the boiling point of silicone based brake fluid is even higher than standard DOT 4 spec stuff.
3/ Silicone brake fluid is a lubricant (which cannot be said of ordinary DOT 4 stuff) so all moving parts within the hydraulic circuit are lubricated..........................for life!

D.

^{_{Subscribers  do not see these advertisements}}

 

[Al-Di]

as said above use dot5 does not harm any seals have used it for years with no ill effects and never needed changing, all my fleet run on it, 5cars/vans MH and 2 bikes,

 

[Tootles]

Can you "see" the degradation of brake fluid through moisture takeup with the naked eye?

Yes. Try specsavers......

 

[Techno]

I changed mine when I bought it three years ago (as a four to 5 year old). I'll not do it again unless I notice any drop in braking performance.
My car was bought new in 2009 and original fluid, stopping it super sure.

^{_{Subscribers  do not see these advertisements}}

 

[Tootles]

I changed mine when I bought it three years ago (as a four to 5 year old). I'll not do it again unless I notice any drop in braking performance.
My car was bought new in 2009 and original fluid, stopping it super sure.

When it's getting 'old', you can tell by the change of colour, from opaque to a brown/orange. Rub a little drop between your fingers. Old fluid picks up a tiny amount of water, and so loses its viscosity. Compare to a drop of new stuff out of the can, when it starts to degrade, you can feel the difference. Lastly, take a 'sniff'. Old fluid actually smells 'old', or ripe, compared to the new stuff.

 

[Techno]

Mine is all clear on all our vehicles

Actually April 13 I did the van

 

[Techno]

Watch your fluid level! you should never top it up. If it is approaching the minimum it is telling you to check /change the pads front rear or both. New pads will force the fluid level back up

^{_{Subscribers  do not see these advertisements}}

 

[PeteH]

Upgrading to silicone fluid is generally not recommended without replacement of all seals in the system. Sad really that motor manufacturers don't install it as standard as its:
1/ Non hygroscopic so doesn't attract moisture out of the air, in fact silicone is repellant to moisture.
2/ the boiling point of silicone based brake fluid is even higher than standard DOT 4 spec stuff.
3/ Silicone brake fluid is a lubricant (which cannot be said of ordinary DOT 4 stuff) so all moving parts within the hydraulic circuit are lubricated..........................for life!

D.

Yes, That was my understanding, I do not wish to start rebuilding the Braking system from scratch. But I will get round to replacing the current fluid (07 Ducatto should be DOT4?) when I get the time and a dry day as I have to work outside!.

BTW. I had the one man bleed system, years ago, it vanished when my youngest son moved out!!. And now my "pedal Pumper" (grandson) has gone to College in S Shields, to follow in in Grandpa`s wake. I may have to invest in another!!.


Pete

 

[dave newell]

I changed mine when I bought it three years ago (as a four to 5 year old). I'll not do it again unless I notice any drop in braking performance.
My car was bought new in 2009 and original fluid, stopping it super sure.

I hate to say it Andy as I respect your intelligence but there is a flaw in your logic here. When you notice a drop in braking performance it could be too late. Fluid boiling will only occur on long and steep descents, this is a bad time to discover your fluid has water in it. You can buy a basic fluid tester for under a tenner
http://www.ebay.co.uk/sch/i.html?_f...+tester.TRS0&_nkw=brake+fluid+tester&_sacat=0
Not entirely the most accurate method but far better than just looking at it and it will give an earlier indication of moisture in the fluid than waiting till your brakes are iffy.

D.

 

[PeteH]

I hate to say it Andy as I respect your intelligence but there is a flaw in your logic here. When you notice a drop in braking performance it could be too late. Fluid boiling will only occur on long and steep descents, this is a bad time to discover your fluid has water in it. You can buy a basic fluid tester for under a tenner
http://www.ebay.co.uk/sch/i.html?_f...+tester.TRS0&_nkw=brake+fluid+tester&_sacat=0
Not entirely the most accurate method but far better than just looking at it and it will give an earlier indication of moisture in the fluid than waiting till your brakes are iffy.

D.

Looks like a Damp Meter? In miniature, I wonder?.

Pete

^{_{Subscribers  do not see these advertisements}}

 

[dave newell]

Looks like a Damp Meter? In miniature, I wonder?.

Pete

It's a simple resistance tester, not unlike a pin type damp meter but I suspect a different sensitivity.

D.

 

[Techno]

Tested mine having received the recommended tester.
What do people reckon the reading is after 2.5 yrs? DOT4 BTW

 

[Jaws]

dot5 fit and forget(to some degree)

Really not a good idea to be honest.. On the face of it yes it is..
But..

DOT 5 is one of several North American designations of automotive hydraulic brake fluid, denoting a particular mixture of chemicals imparting specified ranges of boiling point.

DOT 5 is a silicone-based brake fluid (contains at least 70% by weight of a diorgano polysiloxane[1]).

Unlike polyethylene glycol based fluids, Dot 5 is hydrophobic.[2] An advantage over other forms of brake fluid is that silicone has a more stable viscosity index over a wider temperature range. Another property is that it does not damage paint.[citation needed]

Using DOT 5 in a DOT 3 or DOT 4 system without proper flushing will cause damage to the seals and cause brake failure.[citation needed] DOT 5 brake fluid is not compatible with anti-lock brake systems. DOT 5 brake fluid absorbs a small amount of air requiring care when bleeding the system of air.

I have seen people say it is not a problem to mix the dots ( so to speak ) but when questioned it turns out they have either not done any testing them selves or at best have tested at room temperature over a few days rather than at 100C + for extended periods

^{_{Subscribers  do not see these advertisements}}

 

[pappajohn]

As a complete numpty and may I say never having a problem with "brake fluid" perse. I thought brake systems were sealed, so where does the water come from?
Having said that I always change the fluid in my bike every 2 years cos I'm not prepared to take risk being such a numpty.

Brake fluid is hygroscopic and will absorb moisture from wherever it can....including the small vent hole on the master cylinder lid......and if topped up from a previously opened container.

 

[Techno]

What do people reckon the reading is after 2.5 yrs? DOT4 BTW

0%
The 1% light comes on for a fraction of a second before going out.

 

[tonyidle]

A problem with silicone-base fluids is the opposite of what you might expect. It's correct that it does not absorb water. It's so good at not absorbing water that, if any water enters the system, or is already present if normal fluid has been used previously without changing seals & thoroughly flushing, it collects at the lowest point. Normally a rear wheel cylinder where it causes corrosion & the cylinder to fail. It would presumably cause a dramatic loss of braking power when it boiled under heavy braking too. One of my interests is in classic cars & brake fluids cause some controversy amongst owners. I've used it after draining old fluid & without changing seals & have experienced water in rear cylinders. I also had 10 years experience of it in a vehicle after fitting an entirely new braking system. I bled each wheel after 10 years (-ish) & it was as good as the day I poured it in.

^{_{Subscribers  do not see these advertisements}}

 

[PeteH]

A problem with silicone-base fluids is the opposite of what you might expect. It's correct that it does not absorb water. It's so good at not absorbing water that, if any water enters the system, or is already present if normal fluid has been used previously without changing seals & thoroughly flushing, it collects at the lowest point. Normally a rear wheel cylinder where it causes corrosion & the cylinder to fail. It would presumably cause a dramatic loss of braking power when it boiled under heavy braking too. One of my interests is in classic cars & brake fluids cause some controversy amongst owners. I've used it after draining old fluid & without changing seals & have experienced water in rear cylinders. I also had 10 years experience of it in a vehicle after fitting an entirely new braking system. I bled each wheel after 10 years (-ish) & it was as good as the day I poured it in.

I have used Silicone fluid too. BUT ONLY in "new" (rebuilt) Classic car brake systems without ABS. Both have been OK as far as I can ascertain, One Triumph Vittesse, passed on to an old colleague Is still, I believe, running on the original fluid put in in 1993ish.

Pete