water valve vacuum line?

[Woodie UK]

Just doing a bit of servicing on my 312 Y-block this morning, prior to replacing the vacuum wiper motor with an electric job, and noticed that the feed for the old vacuum motor comes off a t-piece....the far end of the pipe going to the water valve (see photo).

Can't find any reference to this in the shop manual so was wondering why a vacuum line needs to go to that valve?

[Herman Munster]

That's what controls how the hot water circulates through the heater core. The heat control lever on the heating / ventilation operates the vacuum that goes to the valve on the manifold. I think there is a diagram in the shop manual but it might not be more than a flow chart. I'll have to look at it again.
Yes, the whole write up starts on page 265 in the shop manual.

[big job]

Wiper and heater with a tee? Thats not correct. Wiper direct vac. heater vac control
goes to the dash temp control that has vac direct vac line to engine and control back to
water vac control. This regulates hot water. This is common for the newer. Don't know
what year you have. Older temp usually control-ed by a blend cable operated door in the
heater. If you are in the 50's or so my big bet is somebody put that there only for an
elbow and used straight vacuum for hot water. I don't think that suppose to be there,
most besides a blend door have a hot water cable operated valve in the rubber heater
hose. We are a Ford shop pre smog stuff to Model T's we need the year, truck,car etc.
sam

[Woodie UK]

Thanks Guys,
Yep found the explanation of p265 of the shop manual just as 'Herman' suggested. Makes sense now.
Colin

[Rink52]

looking for the temp cable controlled vacuum valve for 52 Ford 239cid or a suitable mech/vacuum valve. any suggestions ??

[KULTULZ]

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Originally Posted by Rink52

looking for the temp cable controlled vacuum valve for 52 Ford 239cid or a suitable mech/vacuum valve. any suggestions ??

Should be B5A 18495-A. GOOGLE that PN and you will find.

[chiggerfarmer]

I think that vacuum valve is base number 18502. There appears to be one that mounts on the firewall and one that mounts to heater box. Either B5A-18502-A or B5A-18502-B. It just says 52/56 on both but there may be a way to use any of them. It might just require some fabricating to mount. I'm pretty sure they all worked the same way, even the later 57 & 58 models altho they are different part numbers in the book I have.

Tom

[KULTULZ]

Originally Posted by Rink52

looking for the temp cable controlled vacuum valve for 52 Ford 239cid or a suitable mech/vacuum valve. any suggestions ??

Originally Posted by chiggerfarmer

I think that vacuum valve is base number 18502. There appears to be one that mounts on the firewall and one that mounts to heater box. Either B5A-18502-A or B5A-18502-B. It just says 52/56 on both but there may be a way to use any of them. It might just require some fabricating to mount. I'm pretty sure they all worked the same way, even the later 57 & 58 models altho they are different part numbers in the book I have.

Tom

I think you are correct. There are two systems - one that has the WATER VALVE and REGULATOR combined (B5A 18502-A)(firewall mount) and the other that has the 18495 at the firewall and B5A 18502-B reg valve on the heater box. Seems all is still available.

THANX for the wake-up call. What year publication are you using?

[chiggerfarmer]

I am using the 1964 edition of the 49-59 parts. I think it may be the last edition?
I had a 1954 Ford Crestline that used this heater set up. All the other 54's I have had used the cable operated 18495 valve. I had several of the B5A-A vacuum valves fail. The ones that go on the intake manifold. They were so expensive that I got a 70's vintage inline valve and hooked the vacuum line up to it. They have one normally open and one normally closed. It did not work as well as the original because it did not really respond to the variation in vacuum given by the 18502. But it would turn the water on and off which was better than nothing. Just FYI for folks with a daily driver and a tightly sprung checkbook.
Cheers

[KULTULZ]

Originally Posted by chiggerfarmer

I am using the 1964 edition of the 49-59 parts. I think it may be the last edition?

I had a 1954 Ford Crestline that used this heater set up. All the other 54's I have had used the cable operated 18495 valve. I had several of the B5A-A vacuum valves fail. The ones that go on the intake manifold. They were so expensive that I got a 70's vintage inline valve and hooked the vacuum line up to it.

The 18495 repros are not quality and the NOS suspect. There are vendors that rebuild them. I think that is the way I would go.

[Daves55Sedan]

There were two different operating systems offered during the '50's. You have a vacuum operated water valve on the intake manifold connected to a vacuum hose to a bimetallic control unit located in the heater discharge plenum. That control unit has another vacuum hose connected to a nylon "tee" fitting behind the firewall. The bimetallic control unit is enabled via a mechanical cable connected to the Magic-Aire Temperature control knob on the dash.
A very good illustration of the assembly is shown on page 266, Fig 14, of the 1956 Ford car Shop Manual.
Neither of my '55's have that type, although they were very common. Mine have the capillary tube control unit which does not incorporate a water valve on the intake. Instead they just have a 90 degree elbow fitting there for the water to go to the heater core. No vacuum required for the capillary system.

[paul2748]

Incorrect , at least as the TBirds were concerned and probably the sedan too.

Originally Posted by big job

wiper and heater with a tee? Thats not correct. Wiper direct vac. Heater vac control
goes to the dash temp control that has vac direct vac line to engine and control back to
water vac control. This regulates hot water. This is common for the newer. Don't know
what year you have. Older temp usually control-ed by a blend cable operated door in the
heater. If you are in the 50's or so my big bet is somebody put that there only for an
elbow and used straight vacuum for hot water. I don't think that suppose to be there,
most besides a blend door have a hot water cable operated valve in the rubber heater
hose. We are a ford shop pre smog stuff to model t's we need the year, truck,car etc.
Sam