Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Adding brake fluid to 92 +4

I think I am slightly fluid paranoid at the moment but having topped up my coolant recently I noticed that the fluid in the brake reservoir appears to be well below the minimum level. The cap reads Castrol Girling only and the manual recommends Castrol Girling universal brake fluid.

This sounds a bit old fashioned. Can I still buy this stuff or is a standard generic replacement fluid available?

More important is the DOT number of what is already in there. You cannot mix them as I understand it.

This is worth a read - http://www.gomog.com/allmorgan/brakefluids.html

The GoMog article is a good general primer.

Unless you, or a previous owner changed to silicon brake fluid, chance are what was in there when the car was new was DOT4. Possibly changed to DOT5.1 at a later service.

But if the car hasn't had a brake fluid change for 3 or more years, the whole lot should be renewed, and I'd be using DOT5.1 as it has a higher boiling point (I have boiled brake fluid...). I'm aware the GoMog article says a 2 year life, but in my opinion, with a car that lives in a garage and does not wade, 3 years is ok.

As the GoMog article says DOT 5 is silicon and must not be mixed with anything else.

Thanks for the feedback. I've topped up with DOT4 as the reservoir was practically dry.

Another dumb question, what is the second bottle on the drivers side engine bay for?

Clutch fluid? Expansion tank for the radiator? Washer bottle? Photo?

You are a very small amount away from disaster. The normal usage of brake fluid is very small and barring a leak, the only thing that reduces the level of fluid to a significant degree is wear on the brake pads. Cars I've had with new pads on 'max' were not at 'min' when new pads were needed.

While you have averted problems for now, on the face of it, the car needs attention to the braking system, both for a pad inspection, a look for leaks. and possible replacement of the fluid.

Second bottle is probably the clutch, most are hydraulic these days.

Probably the brake cylinders at the rear are leaking.
Have them checked. My 94 4/4 did just that.

Agreed, its obviously not a good sign though strange as the master cylinder has been changed recently and the brakes were checked by BHM prior to their Goodwood track day. They certainly are working well and if i had not been poking around in the engine bay for other reasons I would not have noticed.

A recent change suggests you have a slow leak under pressure. As you got the work done, I suggest you ring the changer of the master cylinder tomorrow and see what they say. It's not unknown for leaks to occur at joints as the ideal tightness is enough to stop leaks and not much more. You don't do brake nuts up to 'gibbon' tightness!

As for passing inspection, yes I've known a car with a very small leak pass a MOT.