Posted By: MidPenMopar
Raditor fill question, - 01/29/09 11:56 PM
I always wondered if on the stock radiator of the roadrunner you want it filled to the top or leave it a little low ( like an inch below the cap). 
Raditor fill question,
Posted By: MoparforLife
Re: Raditor fill question, - 01/29/09 11:59 PM
with no reserve/recovery system they are filled about to the level of the baffle plate that you can see looking into the neck. Must have room for expansion.
Posted By: bigblock340power
Re: Raditor fill question, - 01/30/09 12:00 AM
I fill mine just touching the bottom of the filler neck. A little below is OK and you can see if it's flowing with an open thermostat. As long as it runs cool or at least with in the temp range, I think either is OK.
Mike
Mike
Posted By: MidPenMopar
Re: Raditor fill question, - 01/30/09 12:02 AM
Quote:
with no reserve/recovery system they are filled about to the level of the baffle plate that you can see looking into the neck. Must have room for expansion.
I just changed from a 7 PSI cap that has an overflow to 16 PSI cap. I still have the overflow hooked though, but i was thinking it should be a little low.
Posted By: RapidRobert
Re: Raditor fill question, - 01/30/09 12:13 AM
with a recovery cap/bottle you would want it full to the ledge where the cap seals to purge as much air out of there as possible
Posted By: MidPenMopar
Re: Raditor fill question, - 01/30/09 12:17 AM
Quote:
with a recovery cap/bottle you would want it full to the ledge where the cap seals to purge as much air out of there as possible
Are all caps designed to let overflow happen or it is just specific ones?
Posted By: RapidRobert
Re: Raditor fill question, - 01/30/09 12:42 AM
recovery caps have the thin piece of metal on the bottom side of the rubber seal about the size of a quarter & it dangles loose.
Posted By: MidPenMopar
Re: Raditor fill question, - 01/30/09 12:50 AM
Quote:
recovery caps have the thin piece of metal on the bottom side of the rubber seal about the size of a quarter & it dangles loose.
Thank you for the heads up. I will check it out.
Posted By: 70Duster440
Re: Raditor fill question, - 01/30/09 12:56 AM
Recovery caps have an upper and lower rubber seal - one seals against the outside or upper edge of the neck, the other against the opening at the bottom of the neck.
Non-recovery caps only have one seal against the opening at the bottom of the neck.
Non-recovery caps only have one seal against the opening at the bottom of the neck.
Posted By: MoparforLife
Re: Raditor fill question, - 01/30/09 12:57 AM
Yes all pressure caps are pressure release and will allow coolant to escape. Caps used with recovery systems have the added seal mentioned above that actually works in reverse to the pressure cap release to allow the coolant to return to the radiator from the recovery tank. This smaller valve perse' seals under the pressure to escape allowing the major seal of the cap to allow the fluid to escape to the tank and upon cool down a vacume is formed in the radiator opening this seal and allowing the coolant back in.
Posted By: MidPenMopar
Re: Raditor fill question, - 01/30/09 01:07 AM
Great info, thank you all for taking the time to clue me in! 
Posted By: MidPenMopar
Re: Raditor fill question, - 01/30/09 01:21 AM
Here's the cap i am using now.
Posted By: RapidRobert
Re: Raditor fill question, - 01/30/09 01:39 AM
a recovery cap
Posted By: MidPenMopar
Re: Raditor fill question, - 01/30/09 01:58 AM
Quote:
a recovery cap
This one actually has a guage built into the top of the cap that tells you the temperture too.
Posted By: RapidRobert
Re: Raditor fill question, - 01/30/09 02:00 AM
take a pic
Posted By: aarcuda
Re: Raditor fill question, - 01/30/09 03:02 AM
mine doesnt have a recovery tank and a stockish type (repro) cap. it likes the coolant an inch low. any higher and it spits its out to an inch low then im good
Posted By: 474218
Re: Raditor fill question, - 01/30/09 10:27 PM
Quote:
I always wondered if on the stock radiator of the roadrunner you want it filled to the top or leave it a little low ( like an inch below the cap).
From the Service Manual page 7-5 under Installation: "(3) Fill cooling system to 1 1/4" below the filler neck seat with water and rust resistor or water and anti-freeze, as required. After warm-up, re-check coolent level.
Posted By: 68HemiB
Re: Raditor fill question, - 01/30/09 11:06 PM
Quote:Quote:
I always wondered if on the stock radiator of the roadrunner you want it filled to the top or leave it a little low ( like an inch below the cap).
From the Service Manual page 7-5 under Installation: "(3) Fill cooling system to 1 1/4" below the filler neck seat with water and rust resistor or water and anti-freeze, as required. After warm-up, re-check coolent level.
Which are fine instructions for a cooling system without an overflow/coolant recovery bottle (which was how Stu's vintage RR was originally delivered). The intent was to provide some headroom in the radiator for the expansion as things heated up, without puking some out onto the ground.
As stated before, with the addition of an overflow bottle, radiators should be filled to the top, with the "headroom" essentially being between the cold and hot lines on the overflow bottle.
To make it even simpler, if you start with a properly constructed overflow system and the radiator anywhere in the neighborhood of filled, a few cycles of going from a cold system to a hot system and then back to a cold system will take care of the level inside the radiator, provided you watch the level in the overflow bottle and adjust things there.
Posted By: 474218
Re: Raditor fill question, - 01/31/09 12:53 AM
Quote:Quote:Quote:
I always wondered if on the stock radiator of the roadrunner you want it filled to the top or leave it a little low ( like an inch below the cap).
From the Service Manual page 7-5 under Installation: "(3) Fill cooling system to 1 1/4" below the filler neck seat with water and rust resistor or water and anti-freeze, as required. After warm-up, re-check coolent level.
Which are fine instructions for a cooling system without an overflow/coolant recovery bottle (which was how Stu's vintage RR was originally delivered). The intent was to provide some headroom in the radiator for the expansion as things heated up, without puking some out onto the ground.
As stated before, with the addition of an overflow bottle, radiators should be filled to the top, with the "headroom" essentially being between the cold and hot lines on the overflow bottle.
To make it even simpler, if you start with a properly constructed overflow system and the radiator anywhere in the neighborhood of filled, a few cycles of going from a cold system to a hot system and then back to a cold system will take care of the level inside the radiator, provided you watch the level in the overflow bottle and adjust things there.
So I take it you think the Factory Service Manual is wrong?
Well I went back and read the cooling section throughly it made no mention of filling the radiator of a car with a coolent overflow system any differently. Then I did a little more reading and the first mention of a overflow coolent recovery system offered for B Body cars was in 1970 and I thought Stu's "vintage" RR was a 69? However I have been mistaken in the past.
Posted By: 68HemiB
Re: Raditor fill question, - 01/31/09 01:09 AM
Quote:
So I take it you think the Factory Service Manual is wrong?
Well I went back and read the cooling section throughly it made no mention of filling the radiator of a car with a coolent overflow system any differently. Then I did a little more reading and the first mention of a overflow coolent recovery system offered for B Body cars was in 1970 and I thought Stu's "vintage" RR was a 69? However I have been mistaken in the past.
I have no beef with you.
I believe that Stu's RR may not have had a recovery system on it originally, but seems to have one now.
I make no claims about the Factory Service Manual's accuracy. It is my opinion and pure speculation that the words you posted were written with a NON-coolant recovery system in mind, during a period of time when coolant recovery systems were not yet in wide use by Chrysler Corporation.
Knowing what we now know in 2009 about coolant recovery systems (by now, a mature system in wide use), there is no need to leave an air gap above the coolant in a radiator so equipped. If one leaves such an air gap, has coolant in the recovery bottle, and cycles the car through a few cold-hot-cold cycles, any such air gap will go away.
Posted By: RapidRobert
Re: Raditor fill question, - 01/31/09 01:25 AM
they didn't have coolant recovery systems(cap/bottle w hose to bottom) in 1969 so the shop manual is right for a period correct non reovery system where you want the level below the filler neck to allow for expansion.
Posted By: mopars4ever
Re: Raditor fill question, - 01/31/09 03:09 AM
Quote:This is correct if you have the correct coolant recovery type cap.
If one leaves such an air gap, has coolant in the recovery bottle, and cycles the car through a few cold-hot-cold cycles, any such air gap will go away.
Posted By: RapidRobert
Re: Raditor fill question, - 01/31/09 03:46 AM
I remember when the coolant recovery system came out in the 70's, they found as much as a 10 degree drop in temp(with no other changes) by eliminating the air bubbles(which do not transfer heat) & speculated that there would be less rust over the long run, same reason,less air.
Posted By: DennisH
Re: Raditor fill question, - 01/31/09 05:43 PM
Good God. This is "more than you could ever stand to know" about radiator caps. I got a stock-looking cap from Nick that doesn't say Made in Mexico on it. Then, a dime-store recovery tank at the Auto Zone where everything is made in China. Then fill to TWO INCHES from the top with new green coolant. 180 stat. Never had a problem. Does not piss/purge.
The first Cruise in Spring usualy shows the puddle beneath radiators due to owners that can't resist topping off.
The first Cruise in Spring usualy shows the puddle beneath radiators due to owners that can't resist topping off.
Posted By: 62maxwgn
Re: Raditor fill question, - 01/31/09 05:53 PM
Quote:Quote:Quote:Quote:
I always wondered if on the stock radiator of the roadrunner you want it filled to the top or leave it a little low ( like an inch below the cap).
From the Service Manual page 7-5 under Installation: "(3) Fill cooling system to 1 1/4" below the filler neck seat with water and rust resistor or water and anti-freeze, as required. After warm-up, re-check coolent level.
Which are fine instructions for a cooling system without an overflow/coolant recovery bottle (which was how Stu's vintage RR was originally delivered). The intent was to provide some headroom in the radiator for the expansion as things heated up, without puking some out onto the ground.
As stated before, with the addition of an overflow bottle, radiators should be filled to the top, with the "headroom" essentially being between the cold and hot lines on the overflow bottle.
To make it even simpler, if you start with a properly constructed overflow system and the radiator anywhere in the neighborhood of filled, a few cycles of going from a cold system to a hot system and then back to a cold system will take care of the level inside the radiator, provided you watch the level in the overflow bottle and adjust things there.
So I take it you think the Factory Service Manual is wrong?
Well I went back and read the cooling section throughly it made no mention of filling the radiator of a car with a coolent overflow system any differently. Then I did a little more reading and the first mention of a overflow coolent recovery system offered for B Body cars was in 1970 and I thought Stu's "vintage" RR was a 69? However I have been mistaken in the past.
I have yet to see a 70 b-body recovery tank.Can you show me one and its location?
Posted By: mopars4ever
Re: Raditor fill question, - 01/31/09 05:56 PM
Quote:Take off the cap when cold and I bet ya the radiator is full now. Note: fill radiator to top if using china or mopar recovery system (with the proper cap)and do not fill it to the top if you not using a recovery tank. Its that simple.
Good God. This is "more than you could ever stand to know" about radiator caps. I got a stock-looking cap from Nick that doesn't say Made in Mexico on it. Then, a dime-store recovery tank at the Auto Zone where everything is made in China. Then fill to TWO INCHES from the top with new green coolant. 180 stat. Never had a problem. Does not piss/purge
Posted By: CHRGR69
Re: Raditor fill question, - 01/31/09 07:03 PM
This one actually has a guage built into the top of the cap that tells you the temperture too.
Sorry, but those caps are crap. I had a new one literally come apart while driving 60 miles to a Mopar show. I just bought a real cap at the show.
Sorry, but those caps are crap. I had a new one literally come apart while driving 60 miles to a Mopar show. I just bought a real cap at the show.
Posted By: MidPenMopar
Re: Raditor fill question, - 02/01/09 05:04 PM
Quote:
Sorry, but those caps are crap. I had a new one literally come apart while driving 60 miles to a Mopar show. I just bought a real cap at the show.
I will be sure to keep my old one with me just in case of said incident. I got this one as a gift from a buddy who has one too. I commented on the fact it was neat to have a guage in the cap so he got one for me. We shall see how it holds up.
BTW the guy who gave me the new cap has a pretty cute wife, maybe i will tell him how good looking she is. You just never know???
