radiator
Racer
Joined: Feb 2007
Posts: 431
Likes: 5
From: Chico CA
Hi. There is no separate radiator cap. The cap on the surge tank is it.
Years ago, back about 1976, I thought about putting the "flush" kit into my Shelby, but was advised by everyone I talked to not to do it. It isn't as effective as a professional flush, and introduces two more potential leakage points to the system. And the Shelby is a 1969, designed to run about 20* cooler than the modern cars, so the failure of that plastic thingy worries me more than ever.
Also, access can be a problem, since the hose routing is a bit tight. And you get that yellow thing sitting out in plain sight if you ever take the car to a show. 32 years ago the only cars I knew of with the inline flush adapter belonged to my uncle the Baptist preacher from the Ozarks and his brother the farmer.
The instructions for a complete flush are to run clear water through it a few times - probably three or four - then refill with proper mix of Dexcool and drinking water. There is a discussion on the forum about the value of using de-ionized or distilled water - that seems a good idea, and my local NAPA store sells the water cheap. Next time, that's the way I'll go.
Put it in perspective. A few years ago, Ford had to flush all traces of coolant out of my wife's Taurus. It was warranty work, so they wanted to keep the costs down. But they didn't use the inline flush thingy. They followed the shop manual instructions, to drain the coolant, refill with water, run to warm up, drain, refill with water, run to warm up, etc. Something like six cycles per the Ford TSB. But they didn't have to cut into the pre-terminated hoses, and the car was sold to a friend's son a few years later. It has about 140k on it now, so that procedure works.
GM doesn't plan on a full replacement, unless contamination is a concern. If you follow the recommended cycle (five years, 150k miles), they expect you to drain all that will drain from the petcock at the lower right of the rad, and refill with an appropriate concentration of Dexcool. 50% is the typical mix.
You drain when cool, refill, start the car, warm up to 210* or so by cycling from idle to 3k RPM until it's warm, then shut down and refill the surge tank. Repeat until you can fill it to the line and have it stay through a warm-up cycle. Let it cool and check it, and you should be good to go.
If you suspect contamination, I'd head to a reputable shop and have it flushed. Fortunately, my regular mechanic also owns a radiator shop, and is extremely honest. He won't flush them unless there's rust, sediment, or other reason to worry that something bad has gotten into the cooling system. He'll flush brake lines, but that's it. Doesn't even flush the transmission. His contention is that it's better to just drain and refill, like the shop manual says.
Of course, Jiffy-Lube will install an inline radiator flush fitting, and will also be glad to use their wonderful machine to flush your transmission.
In any event, good luck. As you may have guessed, I have an opinion on this, but it's just my opinion.
Oh! My Dad had one of those "Wink" mirrors in his '57 Chevy (the ones that run across the top of the windshield and give a panoramic view, but block the top 4" of the glass), but stopped me from putting the Prestone thing on my '62 Thunderbird. He had been an Airframe and Engine mechanic through WWII, Korea, and Vietnam, so I trusted his opinion. As a reward, he gave me a "Wink" mirror...
Years ago, back about 1976, I thought about putting the "flush" kit into my Shelby, but was advised by everyone I talked to not to do it. It isn't as effective as a professional flush, and introduces two more potential leakage points to the system. And the Shelby is a 1969, designed to run about 20* cooler than the modern cars, so the failure of that plastic thingy worries me more than ever.
Also, access can be a problem, since the hose routing is a bit tight. And you get that yellow thing sitting out in plain sight if you ever take the car to a show. 32 years ago the only cars I knew of with the inline flush adapter belonged to my uncle the Baptist preacher from the Ozarks and his brother the farmer.
The instructions for a complete flush are to run clear water through it a few times - probably three or four - then refill with proper mix of Dexcool and drinking water. There is a discussion on the forum about the value of using de-ionized or distilled water - that seems a good idea, and my local NAPA store sells the water cheap. Next time, that's the way I'll go.
Put it in perspective. A few years ago, Ford had to flush all traces of coolant out of my wife's Taurus. It was warranty work, so they wanted to keep the costs down. But they didn't use the inline flush thingy. They followed the shop manual instructions, to drain the coolant, refill with water, run to warm up, drain, refill with water, run to warm up, etc. Something like six cycles per the Ford TSB. But they didn't have to cut into the pre-terminated hoses, and the car was sold to a friend's son a few years later. It has about 140k on it now, so that procedure works.
GM doesn't plan on a full replacement, unless contamination is a concern. If you follow the recommended cycle (five years, 150k miles), they expect you to drain all that will drain from the petcock at the lower right of the rad, and refill with an appropriate concentration of Dexcool. 50% is the typical mix.
You drain when cool, refill, start the car, warm up to 210* or so by cycling from idle to 3k RPM until it's warm, then shut down and refill the surge tank. Repeat until you can fill it to the line and have it stay through a warm-up cycle. Let it cool and check it, and you should be good to go.
If you suspect contamination, I'd head to a reputable shop and have it flushed. Fortunately, my regular mechanic also owns a radiator shop, and is extremely honest. He won't flush them unless there's rust, sediment, or other reason to worry that something bad has gotten into the cooling system. He'll flush brake lines, but that's it. Doesn't even flush the transmission. His contention is that it's better to just drain and refill, like the shop manual says.
Of course, Jiffy-Lube will install an inline radiator flush fitting, and will also be glad to use their wonderful machine to flush your transmission.
In any event, good luck. As you may have guessed, I have an opinion on this, but it's just my opinion.
Oh! My Dad had one of those "Wink" mirrors in his '57 Chevy (the ones that run across the top of the windshield and give a panoramic view, but block the top 4" of the glass), but stopped me from putting the Prestone thing on my '62 Thunderbird. He had been an Airframe and Engine mechanic through WWII, Korea, and Vietnam, so I trusted his opinion. As a reward, he gave me a "Wink" mirror...
