my heater on my 89 formula blows all over (mainly defroster!) and the thing wont switch cycles with control. and theres a loud annoying spewwing sound coming from the control panel do ineed to replace this? will it cause a major vacuum leak ? will it hurt anything?

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1989 firebird formula

Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 heads,350 horse cam,bored.40 over, Edlebrock torker2 intake.

Future mods 400 performer rpm intake (polished) and 600 edlebrock carb, comp roller cam, and way better heads. orpossibly a 383 stroker?

 

My camaro is doing the same thing, luckily mines in storage, but I was thinking the the spewing/hissing sound was just a vacuum leak, i was just going to take the control panal out and locate the leak and replace the hose.

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Flowmaster,Edelbrock open filliment filter with K&N filter in it
160 stat,

 

just wondering what hose?? please help the spewwing is coming from under the vacuum hoses that plug up to the control panel someone told me theres a diaphram inthere i might need to replace true? and if so how???

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1989 firebird formula

Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 heads,350 horse cam,bored.40 over, Edlebrock torker2 intake.

Future mods 400 performer rpm intake (polished) and 600 edlebrock carb, comp roller cam, and way better heads. orpossibly a 383 stroker?

 

I fought the same annoying problem for months. One day while at my local dealership, I mentioned the problem to the parts man who told me to remove the vacuum harness from the rear of the AC/Heater control head and to swab the tubes (which slide into the vac harness) with Vaseline. I'll be damned if it didn't cure the problem at a cost of 30 minutes and a buck or so.

JamesC

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