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).
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.
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
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.
Quote:
a recovery cap
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).
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.
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.
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.
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.
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.
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
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.