My headlights were working fine. I turned them on the other day and they didnt open. I opened the hood and found a split line. I replaced it and several others I thought looked brittle. When I turned on the switch, still nothing. no hissing, no visible leaks. what could be the problem?? help

did you inadvertently bump the bypass switch? its near the resevoir tank

I checked that. I tried it both ways. I can't find anything. I wondered if it needed to run for awhile to build up the tank pressure? nothing works. If it wasn't for the split line that was hissing, I would have thought it was the headlight switch. They never even slowed down or malfunctioned. Just bam, they stopped.

they should open within a few seconds of having the engine running. Do you have the one way check valve in-line installed? If so, pull that and check the line for vacuum right there. If you have a vac guage, (they are cheap) check for vac at all the hose bibs, including the line that goes thru the firewall to the headlight switch. Its like electricity, the vac flows anywhere the hose goes. Start near the brake booster and check for vac all along the route, to the canister and its bibs and then on out to the acctuators. While seemingly difficult at first, they do operate on pretty simple theory. I use my vac guage more than another other diagostic tool. :)

I found the problem. thank you very much sir. Now the problem will be in parts. It was the little valve up by the master cylinder. Just like you predicted.

:thumbsup: another happy customer , pop a pic of your car in here soon as well. :)