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SILICONE BRAKE FLUID??

VS_Pete

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shane_3800

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It was made for motorcycles originally and is only used in compatible systems.
Pretty much if you're not on the race track don't worry about it.
 

the_boozer

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DO NOT MIX this product with DOT 3, DOT 4, SUPER DOT 4 or DOT 5.1 type brake fluids
is clearly written on the data sheet . don't put it in the commodore.
 

Skylarking

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Silicon brake fluids can’t be mixed with glycol based brake fluids. So if you want to use it you’d need to purge all glycol remnants from the system before filling with silicon fluid. This is a big job and required full disassembly (master cylinders and all slave cylinders/callipers). You need to wash all parts with metho to clean them fully (including pipes). Then all parts must be dried and new seals used through before assembly and fitting. Finally you can fill and bleed with silicon fluid.

I used it on an old car’s clutch as I needed to rebuild the slave cylinder due to a leak, so also did the master cylinder at the same time. It was not a daily so spend a lot of time in the garage. It all worked well and I never had an issue but it’s not really worth the effort.

Only benefit to silicon brake fluid is that such doesn’t absorb water. But water absorption issues are easily solved by flushing glycol based fluids every few years... And considering all brake fluids degrade when heated/boiled during hard use, even silicon fluid, you still need to periodically flush old fluid. So there are no real practical benefits now we have DOT5.1 :p
 
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Pollushon

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You use it on race cars because it won't cook and fluids get changed very often. You don't use it on daily road drivers because it won't absorb moisture and keep corrosion at bay
 

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You use it on race cars because it won't cook and fluids get changed very often. You don't use it on daily road drivers because it won't absorb moisture and keep corrosion at bay
DOT5 silicon and DOT5.1 glycol/borate brake fluids have the same dry and wet boiling points (260C/180C) so there is no advantage to using silicon brake fluid for performance and/or racing any longer. DOT brake fluid comparison chart here.

There are better brake fluids than DOT5.1 and that are compatible with glycol glycol/borate brake fluids. As an example Castro’s React SRF has a dry boiling point of 320C which far exceeds DOT5 silicon’s 260C and is compatible with DOT3, 4 & 5.1 fluids.... Its used extensively in motorsport, including F1.

Thus the only real point of difference with silicon is water absorption which isnt really relevant if fluids are changed regularly (which is especially the case in motorsports).

Some swear by silicon use in classic garage queens that hardly driven. Using such fluids means the brake system doesn’t need to be touched for years and years. And it is touched and spilled on paint it doesn’t matter as it won’t eat the pain though it should be cleaned off well. The only proviso with silicon brake fluid is with some early brake seals, the rubber materials weren’t so compatible with silicon and caused the seals to swell but doubt it would be any issue on any commodores :p

Paint shops hate silicon brake fluid cause contamination makes painting difficult and causes fisheyes...

In my mind, using silicon brake fluid and evens waterless coolant seems rather interesting in classic commodores tha5 are primarily garaged and only driven 1k or so a year :p
 
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