Technical Article on Brake Fluid

[svenedin]

I found this in depth article on brake fluid that might be of interest to some people. I searched the forum and this does not appear to have been linked to before.

http://www.mossmotors.com/SiteGraphics/ ... _long.html

[IslipMinor]

Thanks very much for the link. Looking at it quickly, it looks extremely comprehensive and will be very useful as a reference document for the future.

[MarkyB]

dissolved copper levels in brake fluid

Not heard of this before, looks like an interesting read.

[svenedin]

No problem. I am considering a change to silicone brake fluid as part of a complete renewal of my car's braking system. My car is not used for long periods and I'm fed up with seized cylinders. This article discusses the choice of brake fluid with specific reference to British classic cars so I thought it might help others.

[MarkyB]

That's what I've done, for the same reasons.
I don't see anything in that article to make me regret it in the least.

[svenedin]

I agree. It depends what the car is used for but for my car (which is a convertible so used even less) silicone is the way to go when replacing pipes, cylinders and master. The only negatives seem to be more difficulty bleeding, expensive brake fluid and possibly a slightly spongy less precise pedal. Have you noticed anything since swapping over?

[Trickydicky]

Great article
After reading It would seem that the problems with sticking and seized cylinders could be down to the fact that the brake fluid is not being changed as per the service schedule?
As for Silicon fluid would you still get the spongy pedal with a servo fitted I wonder?

[bmcecosse]

Probably even more so.... As far as I know, no car manufacturer uses silicone brake fluid.....

[tysonn]

Possibly because of the price?

[bmcecosse]

I doubt it - compared to the cost of the car. Not even the 'top range' makers use it... must be a good reason.

[svenedin]

Probably even more so.... As far as I know, no car manufacturer uses silicone brake fluid.....

Harley Davidson uses it but that's a motorcycle manufacturer so what you say is correct....Also the US army and some other fleet operators.

[les]

I first installed silicone fluid 14 years ago and have yet to replace any seized components, so it works for me. I cant say I notice any sponginess in the pedal, another point being it doesn't strip paint if spilt. Regarding companies not using it, why would they promote something that might hit the sales of brake repair items! That's a pretty good reason from their point of view!

[tysonn]

Nicely reasoned Les!

[MikeNash]

Thanks for that Sven. MikeN.

[bmcecosse]

By the time modern cars show any significant brake problems - their service and repair has long left the Dealer network.... Interesting to hear HD use it. I have nothing against the stuff - indeed I have a bottle of suitable fluid somewhere (it's used in high vacuum pumps..) I just wonder at the cost/benefit ratio...

[alexmcguffie]

Silicone fluid isn't compatible with ABS due to its higher viscosity. Thats why manufacturers don't/can't use it.

I'm not sure I'd use it on a system with a servo due to the extra pedal compliance but on a well set up standard Minor system I can't see any problem. It might even give a bit more progression to the pedal feel.

[MarkyB]

There is a lot in that article about minimising exposure to air of fluid when you are bleeding brakes and even checking the fluid level that I hadn't considered.
It makes a very good case for fitting a remote reservoir that you can check without having to remove the top every time.
I've ordered a vacuum brake bleeder from Ebay and will report back on how easy it is to use.

[tysonn]

Do you mean the type you hook up to a compressor or that with a trigger to cause the vacuum?I bought the Sealey comressor type a few months ago and it works great.The trigger type would prob be less hassle of course not having to power up the comp.

[bmcecosse]

Just use GRAVITY - it's free!!

[MarkyB]

The trigger type, the other sort would be limted to where an air-like would reach so a garage or workshop that I don't have