How to Change Brake Hoses with Minimum Loss of Fluid?

[NC TRACKRAT]

I posed this question over on the Concours Forum and thought I'd pose it here to see if anyone has a trick they care to share: 

With the original style disc brake reservoir, does anyone have a trick to minimize loss of fluid while replacing brake hoses?  As I recall with the later dual circuit MC, you can depress the brake pedal down about 1/3 of the way down and it will inhibit brake fluid loss.  I don't thing that will work on the early version MC....or will it?

[Steve McDonald Formally known as Mcdonas]

Take the big cap off the master cylinder, lay a piece plastic wrap over it ( check to make sure the plastic wrap you use is compatible to brake fluid) snap the cap back on and quickly change the hoses. The cap and the original rubber seal allowed air to enter the top of the master cylinder and the rubber seal acted as a diaphragm. The plastic acts as a seal so air won't enter . Used to use parts bags when opening brake systems to prevent fluid loss. Some will leak out, but not much.
You can also use a similar trick when replacing temp senders by taking the radiator car off and putt a plastic bag over the radiator fill and reinstall the cap. The idea is to not let the venting designed in the system to work, just remember to take the bag off  when done and watch for spills

[NC TRACKRAT]

Thanks, Steve.  Will give that a try!

[kingchief]

Thanks for both the brakes and replacing temp senders.

Cheers,

Steve

[Helmantel]

I addition to that, I usually use a bleeder valve cap to put on the brake line if I take the hose off. A flared brake line end has about the same diameter and the cap will seal it off nicely. Of course, you will spill a little, even if you do it quickly.

[Steve McDonald Formally known as Mcdonas]

+1