silicone hydraulic fluid, why not DOT5 silicone? Options

[worn]

We run silicone brake fluid in our LBCs (Little British Cars) and this is widely accepted among that crowd. This week I am putting new front wheel cylinders in the 47 Dodge P.U. truck cause we don't run it enough and they pitted.

So why not use the silicone fluid in a 914? Yes, there is a slight compression you can feel in the pedal, but in my TR6 you can hardly feel it. I now have enough toys so that routine maintenance is a pretty big chore. Keeping up with batteries and tires is bad enough. Yes, I know that you should bleed out the old fluid, but frankly I doubt that would have helped me with the truck. The problem was the lack of movement of the seals over the cylinder. My time flies!

So - what do you think?

Thanks,
Warren

[PlaysWithCars]

Warren, I've had similar thoughts to reduce maintenance on the fleet but ultimately resolved to use DOT 4 and just monitor the moisture in the fluid with a simple tester. They are available through amazon for about $10. This has given me peace of mind that I'm not neglecting the brake system on little used cars without needing to change the fluid every year. .

I saw Ed on Wheeler Dealers use this one time and it got me motivated to investigate. So far so good. The tester confirmed my gut feeel on which cars had marginal fluid and which should still be fresh.

Brake fluid tester

[worn]

Warren, I've had similar thoughts to reduce maintenance on the fleet but ultimately resolved to use DOT 4 and just monitor the moisture in the fluid with a simple tester. They are available through amazon for about $10. This has given me peace of mind that I'm not neglecting the brake system on little used cars without needing to change the fluid every year. .

I saw Ed on Wheeler Dealers use this one time and it got me motivated to investigate. So far so good. The tester confirmed my gut feeel on which cars had marginal fluid and which should still be fresh.

Brake fluid tester

I saw that tester on the JEGS site. I probably will try it, since when I had the opportunity to change to DOT5 with the P-cars I didn't take it.

I can say that during a period of five years with the cap tightly on the master, and the truck staying always indoors, the brake system absorbed enough water to put deep rust pits in a wheel cylinder. Rust lined the bottom of the wheel cylinder like mud in a culvert. I used only freshly opened fluid and new components - master, wheel cylinders, hoses, etc. The system was flushed and clear to start. But the truck was exposed to summer humidity (which I have never learned to like). Had I both bled the system and driven it this would not have happened.

I now have a better understanding of how some of you folks feel about it. Sounds like it is to some degree a personal or cultural thing. Some of us fantasize or participate in days at the track. Others want to ford streams. Which is fitting given one Porsche design



Panzer VIII Maus. The vehicle's weight made it unable to utilize most bridges, instead it was intended to ford to a depth of 2 metres (6 ft 7 in) or submerge up to a depth of 8 metres (26 ft 3 in) and use a snorkel to cross rivers.

I better put the top up.