Braided Brake Lines

[szicree]

I've decided to go with steel-braid hoses for the brakes in my 4 and have what is probably a stupid question. I believe the hoses will come with steel ends, but I've got aluminum fittings on the plane. Can I screw a steel fitting onto an alum fitting without worry?

Steve Zicree

[RV_7A]

Yes, #3 AN steel braid lbrake lines only come with steel ends. It will work without issue.

-Jeff

[osxuser]

Just be sure if you use torque values to only torque them to the value for Aluminum so you don't strip them.

[thallock]

Jeff,
Are you sure? Won't the aluminum contacting steel cause current to flow along the brake lines due to dissimilar metal contact? I've heard that brake fluid is highly flammable. Won't this cause the aircraft to explode and drop out of the sky? The brake lines are pretty long. Won't this at least setup a magnetic field that will render his radio useless?

Tracy.

[ericwolf]

Originally Posted by thallock

Jeff,
Are you sure? Won't the aluminum contacting steel cause current to flow along the brake lines due to dissimilar metal contact? I've heard that brake fluid is highly flammable. Won't this cause the aircraft to explode and drop out of the sky? The brake lines are pretty long. Won't this at least setup a magnetic field that will render his radio useless?

Tracy.

I think that the current you are talking about is that which causes galvanic corrosion. When dissimilar metals (with different galvanic potentials) are in contact with an electrolyte, current flows and causes corrosion. However, I believe that the brake fluid will not act as an electrolyte and therefore is a non-issue.

In any case, the potential is on the order of a few millivolts at most, meaning the current is extremely low. Not nearly enough to cause any magnetic field much less cause a fire. If this were the case, we would have power plants made out of two big blocks of dissimilar metals.