1986 Honda accord

My Honda starts missing and dies when I use the brakes. Why?

Please give us the maintenance history of what you have done so far. It sounds like an electrical problem but other factors will likely be present as well.

A car that age should have at least new plugs wiring and a number of other items replaced by now.

That year Honda could be had with a carburetor or fuel injection.
With a carbureted version, a vacuum leak or carburetor idle circuit issue, anti-diesel solenoid issue, etc is a possibility.

With a fuel injected version the most obvious things would be a vacuum leak or idle air control valve problem.

There’s a plethora of other things that could be involved with either version such as incorrect ignition timing, engine wear, tight valve lash, etc, etc. and even with details provided any online diagnosis is a guess at best.

Are you loosing brake fluid? Maybe a bad brake booster?

Thanks that gives my a place to start

+1 for @keith. You have the classic symptoms of a bad (leaking) power brake booster.

Concur +2 for Keith, first place to check is a vacuum leak in the brake booster. You press the brakes, unmetered air goes directly into the intake manifold through the brake booster leak, and you end up with a lean mixture, so the engine stalls or runs rough. Good idea to monitor the coolant temp gauge for any signs of overheating too until this is fixed, as lean mixtures can cause engine overheating. Fixing a leaky brake booster is relatively easy and inexpensive. Fixing a warped head from overheating, not so much.