Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing What brake fluid to use

If the prior owner used Dot 5 I would continue to use Dot 5. However, if not I would just Dot 4 and change the fluid every 2 years.

Button
Seattle - Cold and Wet

My argument is not if Dot III, IV is better or worse than Dot 5. It is a PITA to change hydraulic fluids back and forth.

Button
Seattle

Dot 4 is commonly used in many cars and more than adequate for a Sunday driver. Brake fluids absorb water with time, part of the reason rear brake cylinders cease up on Morgans. Brake fluid should be flushed through and replaced at least every 2 years, especially on a car that sits around in a garage not doing many miles. That's my view for what it's worth.

Do not change from one type to another without changing all the seals in the braking system. Using a different fluid (can't remember which way round now) can make the seals swell and makes for "interesting" braking issues.
Simon

So it seems the majority favours DOT4. I have heard things about DOT5, but seems to relate to not being able to switch back and forth.

I think I will go with the majority and use DOT4. I will do a bit more research to confirm that DOT4 aligns with my expectation of the use the car will get.

Thanks to all for your input