synthetic Brake fluid

[michael47]

G,Day All
My roadster has always had synthetic brake and clutch fluid ,I am very happy with the brakes but wonder about synthetic fluid in the clutch .Any opinions about this?
Thanks
Michael

[scott h]

Re: synthetic Brake fluid

It is rare to find brake fluid that is not synthetic, i.e. most brake fluid is not made from mineral oil. So if it says DOT3 or DOT4 it is synthetic. DOT5 is silicone based and should never be mixed with DOT 3 or 4. A few cars such as some Citroën models use LHM brake fluid which is made from mineral oil and again should never be mixed with any other type.

[michael47]

Re: synthetic Brake fluid

It is rare to find brake fluid that is not synthetic, i.e. most brake fluid is not made from mineral oil. So if it says DOT3 or DOT4 it is synthetic. DOT5 is silicone based and should never be mixed with DOT 3 or 4. A few cars such as some Citroën models use LHM brake fluid which is made from mineral oil and again should never be mixed with any other type.

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Sorry I miss typed It is using synthetic in both systems that I was concerned about.Over this side of the pond DOT 5 is marketed as synthetic as compared to DOT 3-4 I am using DOT 5 in both and the clutch has never felt right

[stevejgreen]

Re: synthetic Brake fluid

The Marina clutch is prone to poor bleeding. Have you air in the system?
When bleeding, the bleed nipple must be high, on later cars a longer bleed hose was fitted taking the bleed point to cylinder head level.
Rather than pushing fluid throug I found that a vacuum system does better at sucking air bubbles out.
Cant think that Synthetic will make a difference to the feel.

[greyV8pete]

Re: synthetic Brake fluid

G,Day All
My roadster has always had synthetic brake and clutch fluid ,I am very happy with the brakes but wonder about synthetic fluid in the clutch .Any opinions about this?
Thanks
Michael

Hi Michael. I have been warned by the people that supply the spares for my 60 year old classic not to use the synthetic (i.e. silicone) fluid in my car braking system as the older seal rubbers will not cope with it. Peter.

[Tony Stott]

Re: synthetic Brake fluid

A neighbour, english, has been restoring a Delaney special, based on ford running gear, he resealed the braking system, used dot4 fluid and within a couple of weeks the piston seals had swelled. He again resealed em and used mineral based fluid with no problems!

[copperleaves11]

Re: synthetic Brake fluid

I,ve used silicon brake/clutch fluid in the old jalopy since 2004, no problems so far. It is'nt hygroscopic so does'nt attract moisture, therefore the internals of the system are less likely to rust and lasts forever.

[stevejgreen]

Re: synthetic Brake fluid

I think the point about swapping fluids without a thorough clean, and removal of all traces of one fluid, and then a change of seals, causing problems may be relevant.
If you start with a virgin system, stick with your choice.

[Tony Stott]

Re: synthetic Brake fluid

His system was to all intents and purposes virgin him having renewed all the pipework as it was a mixture of metric and uk/American fittings! He was sorted by someone specialising in Ford specials, He passed my place earlier this afternoon in the beast, do a search on 1954 Delaney Delta!

[h_m_cumming]

Re: synthetic Brake fluid

My Roadster has had sil. fluid in the brake and clutch systems since I built it, 1990, and it's been fine. Never been changed and just the odd top up when i've been working on something.

[michael47]

Re: synthetic Brake fluid

Thanks all .I will check the bleeding on Sunday .That might be the problem

I,ve used silicon brake/clutch fluid in the old jalopy since 2004, no problems so far. It is'nt hygroscopic so does'nt attract moisture, therefore the internals of the system are less likely to rust and lasts forever.

A neighbour, english, has been restoring a Delaney special, based on ford running gear, he resealed the braking system, used dot4 fluid and within a couple of weeks the piston seals had swelled. He again resealed em and used mineral based fluid with no problems!

Hi Michael. I have been warned by the people that supply the spares for my 60 year old classic not to use the synthetic (i.e. silicone) fluid in my car braking system as the older seal rubbers will not cope with it. Peter.

The Marina clutch is prone to poor bleeding. Have you air in the system?
When bleeding, the bleed nipple must be high, on later cars a longer bleed hose was fitted taking the bleed point to cylinder head level.
Rather than pushing fluid throug I found that a vacuum system does better at sucking air bubbles out.
Cant think that Synthetic will make a difference to the feel.

I think the point about swapping fluids without a thorough clean, and removal of all traces of one fluid, and then a change of seals, causing problems may be relevant.
If you start with a virgin system, stick with your choice.

His system was to all intents and purposes virgin him having renewed all the pipework as it was a mixture of metric and uk/American fittings! He was sorted by someone specialising in Ford specials, He passed my place earlier this afternoon in the beast, do a search on 1954 Delaney Delta!

My Roadster has had sil. fluid in the brake and clutch systems since I built it, 1990, and it's been fine. Never been changed and just the odd top up when i've been working on something.