1957 Monarch heater valve issue

R

rjlester

Senior Member
Had the heater core rebuilt locally, they did a great job and the price was not too bad.

I tested the heater valve on the bench with a vacuum pump and it seems to work there, it opens and closes the valve. But, once attached to the core and installed, it blows heat all the time. There is a slight reduction in temp if you remove vacuum, but still too hot. I even tried blowing a gentle amount of air in there to try and seat the valve, no go.

Before I order a new valve, I have a question. Does the routing of the heater hoses make a difference in how the valve operates? Do I have them reversed? I have the lower hose on the core going to the water pump and the upper hose going to the intake.
 
There could be a number of things wrong.
You may have your temperature control knob on the "Majic-Aire" panel maladjusted so that when you slide the temp control to "off", that does not correspond to closing the valve. You may need to re-adjust the mechanical cable at both ends to achieve getting the valve to close completely.
If that's not it, the vacuum control valve has a stopper inside with a rubber o-ring on it. If that rubber stopper is rotten from old age, it is letting hot water through no matter if the temp control is off or what.
Make sure you have good vacuum hoses with no cracks from water control valve on intake manifold to valve. There is a separate set of hoses from valve to "tee" then on to windshield wiper motor. Make sure there's no cracks in the hoses.
Read your Ford Shop Manual for a good description of how the system works to determine if there are other factors that can effect valve operation. What about the vacuum water valve on the engine? have you tested it?
If the valve is finally determined to be at fault, send it to Lares Manufacturing and they will rebuild the valve for you (for a hefty price).
 
I've checked all the vacuum lines, all is good there. It is not a magic-aire heater, here is what my valve looks like, it is not on the engine, it's actually attached to the heater core itself:

https://www.ecklers.com/1957-58-mercury-heater-water-control-valve-vacuum-operated-49-50574-1.html

I know the valve is at fault from the tests I performed while the engine was running. I can open the little door on the heater housing above the passengers feet, and attach my vacuum pump to the control valve directly. I apply vacuum, I get crazy hot air. I remove the vacuum, it cools down a bit, but not completely off. Valve is not working. What you mentioned about a rubber o-ring failing sounds like my problem.

My 54 Meteor has the control valve on the cylinder head, but this 57 Monarch (Mercury cousin) is different.

So I take it the hoses being switched doesn't make a difference with these valves?
 
Does the routing of the heater hoses make a difference in how the valve operates? Do I have them reversed? I have the lower hose on the core going to the water pump and the upper hose going to the intake
Click to expand...

Reverse the hoses and see how she does. The outlet on the intake is the pressure HOT side and attaches to the lower heater core nipple and the inlet on the WP is the return COLD side and attaches to the upper heater core nipple.

The coolant needs to move bottom to top in the core so as to release more heat (hang time) and hopefully eliminate air pockets in the core.

The valve either closes fully or it doesn't. It could be the valve itself or within the controls.

What TRIM LEVEL is the MERC?

ADDENDUM - (Fr. For Additional Info)

You also have a TEMP CONTROL VALVE shown as 18502 in attached ILL. FORD used this same design on their 57 FORD higher trim levels and w/ or w/o A/C.

526904

Do you have a MERC (MONARCH) WSM? It will make it a lot easier diagnosing and adjust/repair.
 
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Thanks for the diagram, my manual has a misprint, it's missing almost all of the accessories chapter, and has the tire chapter in there twice.

On the trim level, the Monarch is a Richelieu. Not sure what that equates to in Mercury, other than it's one down from the turnpike cruiser.

I've also tested 18502, it works great. It's the 18495 I suspect is the issue. I should also mention that when I bought the car a year ago, the valve was working most of the time. But before we parked it for the winter the heat would not always turn off. Now it never turns off.

Your description of switching the hoses makes sense. Although that is how it was plumbed when I got the car last year, and initially it was working fine. At this point, I'm winterizing stuff all over my acreage, so not sure when I will get back to fixing the heater as it's already squirreled away. I see some OEM valves available online so I might just order one, and install it next spring.
 
Yeah, the 18495 is the ON-OFF in this design and the 18502 controls the amount of coolant flow according to how you set your TEMP CONTROL.

Is your MANUAL a FORD or copy? I have a 57 MERC WSM here but my scanner took a dive. Let me know if and when you need the missing info and I will try to get page copies to you.
 
Thanks Kultulz!

My manual is an actual 57 Monarch version, I was super excited when my Dad found it last year, but was disappointed a couple months ago when I realized it had the big misprint in it. Going to keep an eye out for another one, but if you get me a copy of those pages it would be great. No rush on it, I put the car into a shipping container today for safe winter storage.
 
... but if you get me a copy of those pages it would be great. No rush on it ...
Click to expand...

If and when you need them, PM me and I will get them to you. CRS is advancing quickly and won't remember ... :(
 
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