Author Topic: HVAC vacuum issues  (Read 80 times)

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Offline Ryan

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HVAC vacuum issues
« on: July 01, 2026, 09:55:47 PM »
I’m in the process of resurrecting my 82 beta and I’m trying to sort out the hvac.  I can’t get the vent  flap by the wiper motor to move.  I’ve replaced the vacuum switch behind the heater controls, many hoses, the vacuum “sphere” next to the power steering reservoir and no success.  I did get the temperature slider control to move back to cold when the heater is turned off.

I was thinking of using my smoke tester at the hose between the manifold and the vacuum sphere.  Is this advisable?  Does anyone have a hose diagram?

Thanks

Online SanRemo78

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Re: HVAC vacuum issues
« Reply #1 on: July 01, 2026, 10:15:04 PM »
Hi Ryan, whereabouts are you? Whilst I can't help you with HVAC diagrams I do have some spare parts from an Australian car's HVAC system, some spheres and piping and the dash controls plus a mechanical pump and front radiator plus a few pipes. If you're in the UK and they're of any use you are welcome to them but postage will be expensive due to weight!
Guy
Hawk HF3000 - Square Arch Stratos Replica - owned since 1988.
Skoda Superb Scout 2021. Believed 1of 1 in the UK!
Fiat Panda 100HP and now -
A Lancia Beta Coupe 1981 2 Litre

Offline Ryan

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Re: HVAC vacuum issues
« Reply #2 on: July 02, 2026, 02:29:53 AM »
Thanks for the offer.  I'm located in the states, so postage would probably be even more to ship from Aus.

I've got a parts car that I've been pulling from and a garage full of parts already.  I'm pretty sure that there is a vacuum leak somewhere in the hvac control system. The heater box should come out to really get an idea whats going on, but I'd like to avoid that.

Online SanRemo78

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Re: HVAC vacuum issues
« Reply #3 on: July 02, 2026, 09:37:05 AM »
Does the vent flap by the wiper motor move by hand? It's possible that there is broken plastic on the linkage? There should also be a flap on the heater box that opens when that one closes, if you pull the instrument panel out you may be able to to see it. If that's obstructed by cables/wires it may stop the other flap opening.
Hawk HF3000 - Square Arch Stratos Replica - owned since 1988.
Skoda Superb Scout 2021. Believed 1of 1 in the UK!
Fiat Panda 100HP and now -
A Lancia Beta Coupe 1981 2 Litre

Offline Nigel

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Re: HVAC vacuum issues
« Reply #4 on: July 02, 2026, 10:16:55 PM »
I recall that the vent flap is actuated by a cable, driven by a slide control
on the dash. I don't think it's vacuum connected. The cable supports often break,
allowing the outer part to move, hence giving no movement.

The vac hoses that I removed from my AU spec car were all a bit rotten,
surface cracks all over. This may be your issue. (Guy is talking about my old stuff)
The vac system is complex and extensive. Your car may have an engine-driven vac pump,
adding to the complexity.

Nigel
1984 2.0 Carb HPE [ex Aus] Grigio Finanza.
2007 Mazda 6 2.3 [current daily, highly recommended]
The past:
1980 2.0 HPE White in South Africa [hope it survives!]
1976 1.6 Coupe Lancia Blu [PFG 76R] [probably deceased]
oh,and an Uno Turbo 1997 also in SA [stolen,never recovered]