Hi all,

i recently changed the evaporator and heater core on my eb falcon and i have a few issues at the moment which are really annoying that i really hope some one can help me with:

ISSUE 1:
There is a really annoying high pitched sound coming when the air con clutch kicks in only.

At the start i thought it was either the thermo fan/s or the air con compressor itself, after further analysis i realised the noise is coming from the heater box and not anywhere outside the car. this noise only comes on for a few seconds when the clutch on the compressor kicks in.

I also disconnected the fan in the heater box as the noise was coming out and it wasnt that! So i can confirm its not my thermo fans, air con compressor or heater box fan.. anyone know what it could be??


ISSUE 2:
I have a vacuum problem with the passenger footwell only. the flap stays open so there is constant vacuum to this section for some reason regarless of the fan settings. I did also change the heater tap, what is the purpose of the vacuum into the heater tap? I bought the heater tap brand new off ebay could this be dodgy and causing my problem?

I have got the air con regassed and works awesome now, but these two minor things are really pissing me off. IF anyone could shed some like PLEASE DO!

thanks

I think Question 2 is partially answered by question 1. A high pitched sound like you describe could well be a split hose or fitting allowing vacuum to be lost. When you say you have a vacuum problem in the passenger footwell only, do you mean that air is only felt coming out of the foot vents? If so, I would be looking at the vacuum hose which controls the air flow flappy thing. There is a vacuum tree at the end of the log style EB inlet manifold with two small diametre hoses, one is for the heater tap and the other is for the air flow flappy thing. Check they are both plugged in as you may have dislodged them when you put your new heater tap in. From memory there is also a complex vacuum tree arrangement attached to the heater box/blower motor which may also be leaking vacuum. I guess an easier way to find it would be using a length of 5/16 hose and place one end against each connection while listening for the noise at the other end like a stethoscope. Other people will know where to look more specifically but thats a start.

Thanks for your reply.

You may be correct in regards ot this all being related to a Vacuum issue. Just to confirm the footwell always has air coming out, but if its on the face vent, dash vent or what ever else they function as normal and air comes out from there too.

The soleniod to the footwell is working fine because when i remove tha green vacuum hose to this it closes.

i made sure to connect both the black and green vacuum hoses in the engine bay, although i didnt check the vacuum tree thing (i know what your referring to)

i will check this and see if i can figure it out. it has to be a vacuum as when the noise comes out i accelerate a little and the noise gos away... i really dont want to pull the dash out again

thanks again for your reply.

#1 Hi pitched noise is the TX Valve - not sure why, but with new gasses ive often had a problem with it. Worst at idle.

well i hope not as i dont want to re gass it and change the TX vavle...

i will check that out too though

thanks

ok this is driving me nuts. Short from pulling the dash out (pulled the glove box surround off instead) I checked all vacuum hoses, checked the vacuum tree, and also re tightened the TX valve and the noise and vacuum problem is still there.

the noise is defnitely coming from the heater box area somewhere as you cant hear it at all from the outside.

im at the point of not caring about the passenger footwell vacuum staying open all i want to do is getting rid of this damn noise.

Can some one please tell me what heater tap vacuum does? im thinking more that this could be faulty...

any one have any info??

Thanks.