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

Hello all. I'm restoring a 1962 Plus 4 Supersport. I'm in the reassemble phase and I have mounted the new dual master brake cylinder. I'm installing all new lines, it has new wheels cylinders, new calipers, etc. So no fluid has been run through it.

Which type of fluid is recommended for a car that wont see track time and it wont be pushed hard. It will be a Sunday driver.

Thanks,
Nathan

IMO in your situation best value to performance and availability locally if you ever had a problem and had to add fluid, would be Dot 3. If you wanted something higher performance (withstands higher temperatures) go for Dot 4. Don't use Dot 5 as it's silicone based so doesn't mix and not so available. Cheers

Thank you Broljo.

I would use DOT4

+1 - all I have ever used.

+2 I would stay away from DOT 5. This subject has been discussed on "Mog-Group" ad nauseum. There are Morgan Owners that have used DOT 5 for years and like it. I am sticking with DOT 4.

Button
Seattle

I am a strong supporter of Dot 5 Silicone, especially if you live in a high humidity area, don't drive it often and don't race it. Living in HK for 30 years I did the same as you on a 58 +4. During restoration installed Kunifer lines, stainless racing type hoses(check to be sure they are legal where you live) and Dot 5 silicone. From time to time(3-5 years) I flush the system and check wheel and master cylinders rubber, but rarely have to change. Fluid is always clean and with the racing hoses the brake is hard. Humidity in HK is similar to South Florida.

Tom S

I have used DOT 5 Silicone fluid in several of my vehicles for years with no problems. The first vehicle I put it in was my CJ-3B Jeep that has a marginal drum braking system. I did not notice any change in the brakes, good or bad, but the silicone fluid has been in for 10+ years with no leaking cylinders or other problems.

I am on coastal northern California with fairly high humidity.

A short article on brake fluids: http://www.mossmotors.com/SiteGraphics/Pages/brake_fluid/page1.html

Dave

Why not use 5.1 for fluid it's not silicone based and has a higher boiling point

I've used 5.1 for eight years but I do change it religiously at or before two years. I wouldn't rule out 4.0, but have ruled out Silicon, only because there are just enough stories of 'stickiness' and soft pedals (over many years of classic cars) to put me off.