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MG MGF Technical - Silicone brake fluid

I am a great believer of silicone brake fluid. Using that already for 20 years in my old MG's and they never give any corrosion trouble.
Is there anybody using that in his modern F/TF or is there a reason not to do so?


This fluid is positively discrimated agains by Delphi Lockheed and is not recomended for use in any of their system for a number of technical reasons they specify in the preface of their brake catalogues. Judging by the not uncommon problem of brake problems that are reported by MG midget and MGB owners to me the conditions reported in the Lockheed manuals seems to be borne out.

I am glad to hear you have had apparently good service from use of the fluids but I doubt anyone with an F or TF would wish to run a fluid in a system that the manufacturer catagorically states not to use.

The added complication with ABS and EBD of the current braking systems would be a potential nightmare with fluid of the wrong characteristics, especially those where lubricity is a key function of the working of the system, and where silicone fluids has markedly different characteristics.

Roger Parker

In addition to what Rog has said, I've also heard that silicone based fluids are less heat-tolerant, and will give rise to the symptoms of brake fade sooner than more 'traditional' brake fluids.

This is probably more critical on MGFs/ TFs where the smaller brake discs perform more work (dissipate more heat) than larger discs given the performance and weight of the car.

It is also important to not mix the two types of fluids, and if the rubber components have been exposed to one type of brake fluid, I've been told to renew them if the fluid is to be changed.

Given the disadvantages of silicone, plus the associated costs of changing, this is not a fluid that I'd be tempted to try in my F!
Rob Bell

Thanks for all your valuable comments!! I won'try it in my F. But still convinced that for older cars its a super thing to have. No seizure of pistons whatsoever. Specially TD's are prone to corrosion. As normal brake fluid is hygroscopic it draws too much dampness inside corroding the aluminium cylinders. Specially if you do not use your car that often its super.
But not in an F that for sure,


It was said: "In addition to what Rog has said, I've also heard that silicone based fluids are less heat-tolerant, and will give rise to the symptoms of brake fade sooner than more 'traditional' brake fluids."

While this is true when conventional brake fluid is new or changed regulary, more often than not conventional brake fluids boil at a lower temperature due to their hygroscopic nature and the fact that except for racers few people change their brake fluid regularly. I've seen fluid that looked like mud in some people's cars.

I would not use silicone in ABS systems though.

Guys, I hear what you are saying - and from the perspective of a 'classic' car that is used relatively infrequently, then silicone can start to make sense -especially as you are unlikely to drive it THAT hard, and if you spill silicone fluid, it won't take off all the paint in that concours standard resprayed engine bay...

But on a properly maintained hard-used modern car, nothing I know of beats mineral based brake fluid. I have DOT5 in mine... :o)
Rob Bell

This thread was discussed between 22/02/2003 and 27/02/2003

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