Radiator Question/Problem

[LAKOTA169]

Last November when I parked my car for the winter, I checked the antifreeze and topped it off. Car wasn't started all winter until about a month ago (ran maybe 10 minutes in the driveway). Two weeks ago drove it maybe 2 miles around the neighborhood. Yesterday, I took the radiator cap off and looked in the radiator. Could not see any coolant. There were no signs of coolant on the drive under the cat. Pulled the dipstick and the level was just below full (no bubbles on stick). Took the thermostat housing off (there was coolant in the hose/head under thermostat). The cap I have is not the correct one. The radiator cap opening ie 1 9/16" and the part of the cap that goes in the opening is 1 1/2". Could the coolant have evaporated because of the not so tight seal? The engine is a P23 in a '37 coupe.

[LuckyDevil]

Sounds like a possibility, but I believe these cars are a non-pressurized system anyways. I would put more coolant in there and take it for a drive and make sure you aren't loosing any fluid anywhere else on the engine.

[chopt50wgn]

Like lucky said....look for leaks, let it get hot then check. Also put the right cap on.

[LAKOTA169]

Like lucky said....look for leaks, let it get hot then check. Also put the right cap on.

having trouble finding a cap. There is one on Ebay that says it's for a '37 (cap R-2), but I got one from Paul Curtice that was a R-2 and it wouldn't go on (wouldn't go in the opening). Now I'm trying to find a gasket for the bypass housing. Changing both thermostat housing and bypass gaskets.

[old rat 49]

Would someone please explain the no pressure system. Can it be modified to use a pressure cap and reservoir ?

[greg g]

No. The over flow is seperate from or under the cap. The cap really doesn't make a difference as the vent is below the cap so it can't build pressure. Like a pressure cooker the heat causes expansion the expansion causes pressure, since the vent on these systems is below the cap the pressure goes to atmoshpere without increasing the pressure in the system. The theory of the presurized system is that coolat under pressure increases the boiling point so you can get the same cooling effectiveness from smaller (read cheaper) radiator.

I had a leak I could not find in a car a whole back. It was a small split on the bottom side of a heater hose. Any thing that driped from it droped onto the exhaust pipe and evaporated. Drove me nuts for about 3 months till one cold morning. I checked it with the engine hot and off, and saw the vapor rising from the exhaust pipe. With the engine running the fan would blow the steam away before you could see it, and with the engine running you could't hear the sizzle when the drip hit the hot pipe.

[BobT-47P15]

You can buy a non pressure radiator cap from NAPA for about $3 or $4.

Here's the box they come in.....give em this part number.

"Balkamp" brand part......they should be able to order it from their

warehouse if not in stock. If they can't get it for some reason, let me

know and I can get one here to send you. I think the item model

name is "classic".

Here's the underside.......no spring or anything.........

[LAKOTA169]

OK, let me try it with a pic attached:) Had to go back to work, and in my rush I did not attach the pic:(

Shel, that's the one. I had one here someplace, but can't find it now. Before I needed it, I was always coming across it. I bought some gasket material, so I'll give it a try (but I'll keep you in mind). Thanks for the offer.

Ed

[LAKOTA169]

This is what my old radiator cap looked like (this one on ebay). The bottom view, I added what the opening is on my radiator. On the cap I got from Paul, that part wouldn't fit in the opening.

I was at NAPA yesterday. Will go back with the cap info and see what they have. Thanks

[Frank Elder]

Wow Greg, a real puzzler, I had had one kinda sorta like that, my first and last leaker that required detective work was a dribbling welch plug hidden between the back of the block and the bellhousing....can't remember if it was a 318 or slant 6. I do remember it drove me nuts as the rad level was lower and lower with no discernible leak or water in the oil pan. Finally it blew and my mystery was

solved.

[alan32433]

Lakota,

A non pressurized system will leak water while its sitting almost as fast as when it's running. The Mopar flatheads have a significant number of areas that can leak coolant. Virtually all the bolts into the block, or at least a large number of them, penetrate a water jacket. Head bolts, manifold bolts, and even water pump bolts penetrate water jackets. Most of the bolts have been sealed with some sort of sealer to prevent leaks. After some period of time in addition to heat, the seals can be compromised resulting in leaks.

Having said all that, most leaks are not critical. Especially if it takes a few months to be obvious. If you have checked all the obvious, hoses, gaskets etc and you can't find any problem, then I wouldnt fret too much about it. Of course I would check and refill with distilled water when needed. Adding non distilled water especially if you are doing it often can result in mineral build up and corrosion.

[LAKOTA169]

Shel and BobT, that cap won't work. Just looked, and the neck on my radiator is straight up and down, no lip/flange to hook onto. Shel, I found the gaskets I bought last summer. Thanks for the offer though. Now, a couple more questions. Should I put any RTV/Gasket sealer in the 2 gaskets? Any thread sealer/teflon tape on the bolt threads? Last one (I hope), while I have the thermostat housing off, I've been debating about replacing the 180 with a 160. The 180 is working and I haven't had a overheating problem (even in 90+temps in stop and go traffic). Don't usually drive it in winter. Is there any advantage in the 160 over the 180 (or should I leave well enough alone)? I usually close the heater water valve in the summer (unless the water temp does rise a little). But inside the cab does get a little warm from engine heat when in very slow moving traffic. Would the 160 keep the engine temp down during those times? Sorry for all the questions.

Ed

[Niel Hoback]

My humble opinion; I have used a 160 year-round since 1996. No overheat problems, however, I am sure it would run more efficiently with a 180. I'm just too lazy and cheap to change it.

All thermostat and bypass housing bolts go into the water jacket area so they will all need a thread sealer. I have great success with permatex #2.

This post reflects only the opinions of the poster. Your results may vary.

Take two aspirin and call me in the morning.

[LAKOTA169]

My humble opinion; I have used a 160 year-round since 1996. No overheat problems, however, I am sure it would run more efficiently with a 180. I'm just too lazy and cheap to change it.

All thermostat and bypass housing bolts go into the water jacket area so they will all need a thread sealer. I have great success with permatex #2.

This post reflects only the opinions of the poster. Your results may vary.

Take two aspirin and call me in the morning.

I think I'm running out of aspirin. Thanks, think I'll stay with the 180