automec silicone brake fluid

[dougbgt6]

This is covered in the Buckeye Triumph article and the reason he uses in some of his classics and not others. And of course you mustn't use it wit ABS.

Doug

[SpitFire6]

1 hour ago, dougbgt6 said:

This is covered in the Buckeye Triumph article and the reason he uses in some of his classics and not others. And of course you mustn't use it wit ABS.

Doug

Hi,
I have heard the same.

It is said that the gas air causes the incompatabilty problem with ABS.
Vacuum or don't let the air get into the system seems the answer for ABS & DOT5?

Cheers,

Iain.

Edited December 22, 2022 by SpitFire6
speeling

[johny]

No, dont think its air thats the problem with DOT5 but its actual compressibility. The ABS pulses the pressure in a hydraulic system to prevent brake lock and if the fluid is more 'spongy' this will be less effective...

[alan.gilbert_6384]

55 minutes ago, johny said:

No, dont think its air thats the problem with DOT5 but its actual compressibility. The ABS pulses the pressure in a hydraulic system to prevent brake lock and if the fluid is more 'spongy' this will be less effective...

It’s actually the viscosity of DOT5 that’s the issue with ABS.   

[johny]

Seems like theres multiple ideas on why silicone is not recommended for ABS like: air bubble retention (viscosity?), reduced ABS pump lubrication, pooling of any water contamination and increased compressibility...

[PeteH]

Not an issue for Triumph`s then?.😂 Seriously, Nothing much wrong with DOT-4, the main issue being to replace it aproximately every 2 years or so.

ABS?, Used to be taught as cadence braking.

Pete

[johny]

Dot 4 is great until youve spilt it on your new paint work and then all of a sudden youre wishing it was silicone😭

[68vitesse]

Using a Gunson Eezibleed disconnected the line to the tyre providing the pressure first, sprayed brake fluid, fortunately Dot5, a surprising distance.

Regards

Paul 

[foshi]

done that yesterday with dot 4 , only painted the bulkhead area a short while back poured water over it but too late ruined .

[Unkel Kunkel]

Silicone brake fluid is hardly  a new thing -it has been around since the seventies.

It was an answer to the problem of  fluid deterioration and adverse effects on hydraulics in infrequently used military vehicles which could be  stored for prolonged periods.

A situation in some  ways applicable to my Triumph- that’s  why I use it.

In my ‘daily use “ vehicle, I use Dot 4 and change it every 2 years.

I can’t say I have noticed any differences in bleeding either of them - or in any other way.

 

 

 

 

 

[alan.gilbert_6384]

Hi All,

Now completed the rear brakes with new stainless steel flexes (it already had them, but having the mushy seals before didn't trust them) and brand new cylinders.  I decided new cylinders for the rear as opposed to seals when ordering the spares, as the price difference was small and given that I might find problems was worth it.  Having now dismantled the old cylinders I can easily see corrosion and remnants of the old brake fluid trapped in them (it was changed in 2007 to DOT5, and I replaced old steel lines and re-bleed in 2012).  The corrosion on the them must be a direct result of the old fluid still being trapped in them, as the DOT5 is not hydroscopic.

[Mjit]

On 03/01/2023 at 18:17, alan.gilbert_6384 said:

The corrosion on the them must be a direct result of the old fluid still being trapped in them, as the DOT5 is not hydroscopic.

Or was it a direct result of the DOT5 not being hydroscopic so ending up with any/all the water in the system ending up in the rear cylinders...😈

[Paul H]

General DOT5 ?

Autometic is much more expensive than say Comma DOT5 . Is it worth the premium 

Paul 

[johny]

On 03/01/2023 at 19:17, alan.gilbert_6384 said:

 The corrosion on the them must be a direct result of the old fluid still being trapped in them, as the DOT5 is not hydroscopic.

Or could that be old corrosion from before the system was changed to silicone - seems likely the PO just whacked it in with no seal change....

[trigolf]

3 hours ago, Paul H said:

General DOT5 ?

Autometic is much more expensive than say Comma DOT5 . Is it worth the premium 

Paul 

Paul, do you mean Comma DOT 5.1, rather than DOT 5? 

I think I'm right that they are not the same. DOT 5.1 is synthetic, but not silicone.

[Paul H]

11 minutes ago, trigolf said:

Paul, do you mean Comma DOT 5.1, rather than DOT 5? 

I think I'm right that they are not the same. DOT 5.1 is synthetic, but not silicone.

Thanks and now understand . My clutch slave is leaking and considering moving across to Dot 5 . OKE dot 5 looks best value 

Paul 

[alan.gilbert_6384]

2 minutes ago, Paul H said:

Thanks and now understand . My clutch slave is leaking and considering moving across to Dot 5 . OKE dot 5 looks best value 

Paul 

Hi Paul, don't forget to check the slave bore before ordering seals, or just order new salve ?  Got mine from Lacey classics.

[SpitFire6]

On 05/01/2023 at 16:52, trigolf said:

Paul, do you mean Comma DOT 5.1, rather than DOT 5? 

I think I'm right that they are not the same. DOT 5.1 is synthetic, but not silicone.

DOT 3, DOT 4, DOT 5, and DOT 5.1 are all synthetic.
DOT 5 is the different chemistry.
 

[Peter Truman]

I have a Question re Dot5, my Vitesse has been on Dot5 for 8 years no issue, I use a USA manufactured product called "Maxima Racing Oils" Brake Fluid Dot5, I get it locally here in Melbourne from a Motor Bike Shop, the label says recommended for all USA, UK, Jap, & European motorcycles specifying Silicone brake fluid, with a minimum boiling point of 356F, It meets and exceeds SAE J1705, plus other standards for Dot5 Silicone Brake Fluid.

I've just read the speel on the plastic container and the warnings quote, "brake fluid can damage painted surfaces wash spills immediately with water, & keep container clean and tightly closed to prevent absorption of moisture?"  Surely these two warnings are contrary to the reason we use Silicone Dot5, ie to avoid these outcomes.

Q! are all Dot5 to SAE J1705 the same, & suitable for car use?

 

 

[johny]

I think that must be a generic warning and the spec says suitable for all types of vehicles but yes says use in systems that specify DOT 5 and not those that require DOT 3, 4, 5.1 fluids...

[Clive]

If worried, best to ask the manufacturer. But I agree with johny, probably a generic warning.

[ed.h]

Package designers aren't automotive Engineers.  They probably just brought over that boilerplate text from one of their other brake fluid products.

Ed

[alan.gilbert_6384]

Hi All,

Now finished and bleed the whole system, just need some nice Austrialan weather, to try her out on