Silicone brake fluid (DOT5)

[Dieter H. Marschall]

Hello,

When driving pretty hard in the mountains I found that the pedal way on my TR6 was getting longer and longer, as the brakes got hotter.

So I reworked the whole system using new rubber parts and seals plus DOT5 silicone brake fluid, which does not absorb water and thus does not tend to build up water vapour.

After driving three days in the Black Forest I am very happy with the result.

Of course I am now thinking of doing the same with the Stag. Any opinions or experiences on that topic?

Best wishes,
Dieter.

[TR5convalescent]

Hi Dieter

There are many threads on this topic on the TR register forum. You have done the right thing in renewing all the seals as this is effectively a clean install. However, do not assume that this is fit and forget. While the fluid does not absorb water, water will still get into the system (through the breather hole in the master cylinder and the joints). This then condenses and works its way to the lowest point (the calipers). I know of one TR driver whose expensive Wilwood calipers were internally corroded by water and were scrap after a few years.

It's wise to just bleed the brakes every year or so, even with silicone.

[wilf]

^this.

Silicon fluid was developed for racing, where such things are routinely replaced on a very regular basis. Because the fluid doesn't absorb moisture, the water that DOES get in will "clump" and can give rise to boiling and brake fade.

[Motorsport Micky]

Hello,

When driving pretty hard in the mountains I found that the pedal way on my TR6 was getting longer and longer, as the brakes got hotter.

So I reworked the whole system using new rubber parts and seals plus DOT5 silicone brake fluid, which does not absorb water and thus does not tend to build up water vapour.

After driving three days in the Black Forest I am very happy with the result.

Of course I am now thinking of doing the same with the Stag. Any opinions or experiences on that topic?

Best wishes,
Dieter.

Dieter,

Look down, you have two feet (I hope), I found when racing that using your left foot to give the brake pedal a quick pump half way down the straights and before corners removed any long travel whilst still remaining at full throttle. Benefits ? it's cheap, non labour intensive and puzzles any following race car driver as to exactly when you decide to brake

Micky

Micky

[Stagless Steve]

I have DOT 5 fluid in my Stag which was converted by a previous owner and the brakes work fine. I needed to get some to top it up at the weekend. Could I find it from a local garage or store such as Halfords or CAF - no. One garage said they could get me some and had DOT 5.1 delivered by Euro Car Parts. Beware, this is not an evolution of DOT 5 because DOT 5.1 is yet another polyglycol brake fluid. In the end I got some from the classic oils stand at the Uxbridge Autoshow, £33 for a litre! OK it was cheaper than Amazon but still very expensive.

Having never heard of DOT 5.1 I did Google it to find out what it was and there is some info on the web about the pros and cons of silicone based brake fluid and the cons of silicone fluid seem to outway the pros. If I was looking to update my brake system now I would upgrade to the best (and easy to get in an emergency) brake fluid, probably DOT 5.1. It's a lot cheaper as well!
Steve

[Andrew S]

I changed over years ago and nver looked back. I think the best benefit other than stopping is that it cant damage your paintwork, if anything, it makes its shiny

[73stagman]

Absolutely will never go back to paint rotting water carrying horrible brake fluid...
Use silicone fluid in the brake system and the clutch. Used it for years in a number of older cars..(Not the moderns as I cant be bothered to reseal everything!)
However I would never think of mixing the two (even though its listed as ok to). always use new seals and new silicon fluid. Change it regularly. its easy enough to do and if you have a little spill its just a clean up job not a repaint.
Have not had an issue with brake fade in any of the cars I've used it in and never had a reason to suspect there was anything negative about switching to it.