As the title says, I made a stupid last night.

Brake warning light was on so I checked fluid level. Was below max, halfway between max/min, but not low. Put in a few tablespoons of DOT3 to get it to the max line.

If I suction and refill the fluid canister a few times will that prevent damage, or am I gonna be buying a master cylinder soon?

 

DOT3 won't cause any issues. Feel free to drain it if you're hyper concerned, but as long as it's ABS rated, it will perform ok.

For future reference, DOT5 (silicone) brake fluid is the one that isn't compatible with DOT3 or DOT4.

 

DOT4 has a higher boiling point, and a little different viscosity. Designed for tougher duty, brakes on mountain roads, etc. You have not damaged anything, but the absolute performance is changed by some small factor of the mixed fluids. Sucking it out won't help if truck has been driven there has been some circulation. You can flush the whole system with two quarts of DOT4 and be good to go. While you are inpsecting the brakes and bleeding each you should be looking for that leak or a spongy brake line.

 

Unless your ABS works there's no need to do anything.

 

Wow, well thats good to know.

Whats up with this thread and the disintegration of seals?

https://landroverforums.com/forum/di...e-fluid-13366/

 

That could be a result in a full change, a few tablespoons vs two quarts and volume is on your side.

 

Ok cool. Ill suck it out and refill just to be sure.

Since the top-off last night I only drove it from the driveway into the garage using the parking brake to stop. Also, I took my shifter solenoid out so I didnt have to use the brake even to shift out of park. I assume circulation is extremely minimal?

 

Yes, get out the turkey baster. Note - don't re-use baster for food service - adds flavor

 

Def, Def, Definately suck that resevoir out and you'll be fine..

John

 

All brake fluids begin as ethylene glycol or antifreeze. DOT 3 fluids, for regular vehicles, are made from polyalkylene glycol ether and other hydroscopic glycol chemicals. DOT 4 fluids have borate esters added which raise the temperature of the boiling point for better performance under extreme racing conditions.

As brake fluid sits in the line, it collects moisture, which evaporates to steam, interferes with braking capabilities, reduces the boiling temperature and leads to corrosion.

DOT 4 is designed to tolerate water levels better than DOT 3. Regardless of the type of brake fluid, water levels should be less than 3 percent of the total fluid in the line. For this reason, brake fluid should be changed often to reduce the amount of moisture in the line.

Been racing your Disco lately?

Do you have working ABS? Didn't think so.

Blah blah blah......

We're all going bye bye in a week and a half anyways - 12/21/2012 right? So why worry.....

By all means keep using your parking brake to stop, it's much safer than say mixing DOT 3 with DOT 4. OMG much safer.