MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Brake fluid.

I am replacing the seals on the brake master cylinder.
I would expect to use Dot 4 fluid but I have heard of Dot 5 being used.
Any thoughts?
Roger D

I have always used DOT 4 as I know it is ok. Don't want to risk anything with brakes!!
Bob Beaumont

Dot 5 is not mixable with 4. Do you mean 5.1?

If 5, Seems a lot of faff to flush/replace everything so you have a clean system to ensure no mixing.

If 5.1, What problem would you be trying to solve with Dot 5.1?

Others will have their opinions but I have never had a problem with 4, other than my general hatred of working on brake systems and brake fluid. But then again, I do take things apart more than the average person!

Malc.
Malcolm

I wasn't really planning to use DOT 5 it was just a thought as to whether or not there might be an advantage.
DOT 4 it is then.
Roger D

Dot4 is hygroscopic, DOT5 (silicone) isn't. Also, DOT5 doesn't strip paint.
Bill Bretherton

The two reasons why I use it Bill!
Jeremy MkIII

As others have said you can't mix 4 (glycol) and 5 (silicone) as they are totally different and incompatible. But if you are installing a brand new brake system, all cylinders, calipers, lines etc. DOT 5 has the advantage that it doesn't deteriorate over time, unlike DOT 4 which should be changed every 2 or 3 years. My MGB V8 has had DOT 5 in brakes and clutch for over 14 years and has never needed attention. It just passed an MOT with no advisories, so the brakes must be OK.
Mike Howlett

This thread was discussed on 22/11/2023

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.