First off, I'm leery of silicon fluid on two points. First off, it provides less lubrication than conventional fluids, to the point that it is outright NOT suitable for ABS systems (or hydraulic convertible tops) where a pump requires lubrication. Supposedly this is not an issue for the lubrication of rubber-on-metal type contact that occurs in a conventional brake system, but color me skeptical!

Second, there is the problem that any moisture that finds its way into a silicone-filled system will not be dispersed, but will pooled. I agree that water intrusion is not LIKELY, but it can happen (and especially in trailer brakes). I know that I can perform an annual fluid flush with conventional fluid and get rid of any moisture- I'm not sure that I can do that with silicone fluid.

But if you want to use silicone, I'd probably flush everything with Brakleen (red can 100% tetrachlorethylene, not green-can MEK stew!), and then follow with (dry) compressed air to evaporate all the Brakleen.

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...oh, I'm already decided on the silicone fluid. Tri-chlor it is to flush with, don't know why I didn't figure that out on my own! I was good to get all the pros and cons of silicone fluid as they apply to our cars as well (the other reason I brought this up). Personally, I'll be sticking with good ole glycol based DOT 4 fluid for everything else, but I think the silicone will do much better in my trailer. I may bleed it periodically just to be safe, but I won't have to disassemble and free up nasty corroded wheel cylinders every time I use it.

D/W

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If it ain't broke, fix it!

Glycol-based. DOT 3, DOT 4 and DOT 5.1 are all glycol-based.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

yeah, whatever!

D/W

...ya know a glycol is an alcohol which has 2 hydroxyl groups in each molecule, right?

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If it ain't broke, fix it!

Gravedigging...

Dennis, how is your trailer doing? If Id been hot on this topic, I wouldve suggested taking the wheel cylinders and sending them out to get stainless steel sleeves installed in the bores. John Stuart Power Brake does that service up here, and they guarantee their units for life in any application.

This way you could use the glycol based fluid without any worry of seized wheel cylinders.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

I like the silicone because it doesn't attract moisture. The moisture would still work on the brake lines and cylinder pistons etc... also very expensive. The wheel cylinders that I have installed now are aluminum (al-yoo-minny-um for the Canadians here ). Haven't used the trailer since I upgraded. I will report back to let you know how they're "keeping" next time I use it. That's the whole deal - it gets infrequent use. I also replaced one of the bolts for the brake damper (a shock absorber) with a removeable pin so I can easily go out there and pump them by hand occasionally to keep the residual pressure up so they won't be as likely to seep past the seals.

D/W

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If it ain't broke, fix it!

I view that as silicone fluid's downfall in a passenger car or truck brake system; Moisture still gets into the brake system, and it simply sinks to the lowest points in the system and stays there in concentrated slugs, munchin' on the metal it contacts. A trailer system, maybe not so much since there really aren't too many hills and valleys in the system.
We say "uhLOOMinum"; you're thinking of the Brits!

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I've never used silicone fluid. I was considering it a couple of years ago until I read that it is difficult to get all the suspended air bubbles purged from the system which leads to a spongy pedal. With power brakes on the Dakota the pedal is spongy enough without further assistance from pesky suspended air bubbles.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

No, I know that's the Brits, but I figured since you folks up yonder in Canada like so much to mimic the British by "colouring" your langauge and lives with lots of other cutesy Brit stuff like "centre" and the metric system, you probably would just love to say "al-yoo-minny-um", "bonnet", "lory", "petrol" etc... Oh, wait, you do say "petrol" up there!

D/W

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If it ain't broke, fix it!

Only when we're mocking Brits and Aussies! The rest of the time, we pronounce it "Beer".

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一期一会
Too many people who were born on third base actually believe they've hit a triple.