1995 f-150 a/c

alright nobody can figure my problem out but i need to fix it. i have a 1995 ford f150. 302. 4x4. 180k. auto. everytime i am driving and i am going uphill or hammer down on it my a/c goes to defrost and to the floor vents. also when i start the truck, sometimes the rpms fluxuate up and down rapidly till it stalls. knowone can figure it out and i need some help. ive check the vac lines from the canister. bought a new canister. can't find and vac leak anywhere. replace check valve in the canister lines. im clueless and frustrated. this is my only vehicle and i am a single father of 2 lil ones.. help me please!!!!! mike ([email protected])

Pull the vacuum hose to the brake vacuum booster and put a bolt in it does this make the engine run better. If it does get a rebuilt or scrapyard replacement booster. Spray along side the intake manifold with carb. cleaner if it immediately smooths out replace the intake gasket.

My 95 F-150 5.8L was doing the same thing minus the idling problem. Mine was the little vac check vlave. Yours definately sounds like a good size vac leak. Do what RH said and make sure to double check those plastic vac lines. I found one of mine up at the recirc valve (the white one) was dry rotted and rubbed through from the hood.

Yeah, a brake booster can lose a lot of vacuum though. That's a large vac line. Inspect that check valve there at the booster while you're there.

Good Luck