Triumph TR3A brake service Dandy Classics workshop

DOT 5 brake fluid in your classic car? Don’t do it!

Although at Dandy Classics we are always interested in innovative products for classic cars, we have a rather traditional approach in our workshop. Our cars were designed to be serviced in a certain way, and one needs to respect that while also taking into account the many innovations in lubricants, coolants and other fluids. Take DOT 5 brake fluid for example. In theory, this is a perfect product for our classics. It is not agressive to paint and does not attract moisture. This means that in principle the brake fluid will never have to be replaced.


A practical story about DOT 5 brake fluid

So far the theory. As often as this is not always 100% consistent with practice. Especially not when a perfectly restored Triumph TR3 rolled into our workshop. As a matter of fact, it didn't roll very well anymore, as the front brake calves were quite tight. The braking system had been completely renewed and / or refurbished by a well-known company during the car's body-off restoration. The hydraulic system had been filled with DOT5.


Adhesive rubber brake parts

When removing the brake pads we noticed a lot of black contamination. These small particles had been dissolved rubber parts of the soft parts of the hydraulic brake system: the master cylinder, brake calipers and possibly the brake hoses. Pollution leads to blockages and blockages in the end lead to sticky brakes. Conclusion: The brake fluid had affected the rubber.


Triumph TR3A brake service DOT 5 fluid


The remedy

In order to switch over to conventional DOT 4 fluid, there is only one solution: Rinse the entire braking system (clean metal pipes inside) and replace all the soft parts. This comes down to a complete rebuild of the braking system. To be on the safe side, we did the same for the clutch circuit.
All in all, a full day's work and big bill for the customer. It's a shame we had to do this on a restored car which already had the hydraulic system completely renewed. In theory, opting for DOT 5 prevented advisable bi-annual replacement of the brake fluid. In any case, replacing the brake fluid every 2 years is a lot more economical than solving these types of problems.

Brake parts for Triumph TR sports cars

We keep a stock of new brake parts for Triumph TR3, which can be ordered in our parts webshop. If you want to rebuild the brake system of your Triumph, please be aware of the harmful and potentially dangerous effects of DOT 5 in your classic car.

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