Radiator cap

Post by **HenryJ** » Fri Aug 01, 2003 5:12 am

Do me a personal favor and the next time you go by the auto parts store, stop in and get a good radiator cap.

The stock GM cap is very poor, and yes I'm talking about even new ones.

The problem is that the upper gasket is made from a fiber base, which is nice because it doesnt crack like the rubber based seals, but it does shrink a little and just by its nature does not seal well.

The next problem is that the ID of the upper seal is barely smaller than the rad opening, so there is very little contact. If the gasket (seal) shifts even a little, air can enter the system.

For the Dex users this is VERY bad! (Dex + air = contamination)

The new cap will also improve the system performance by holding a higher pressure, which will be less prone to "boiling over"

This is not a big expense. I paid $5.09 for a new Stant cap with pressure relief lever. It has smooth rubber seals and fits just right.

quickbiker · Post by **quickbiker** » Fri Aug 01, 2003 7:10 am

Thanks for the info!

Conman · Post by **Conman** » Fri Aug 01, 2003 9:32 am

any special part number or it's generic?

Thanks,

Con

a2b · Post by **a2b** » Fri Aug 01, 2003 10:00 am

was this just a random thought you came up with???

hahaha. i like that. just answer questions before people even aske them

ya, we all replaced our radiator caps a long time ago

Post by **HenryJ** » Fri Aug 01, 2003 3:03 pm

a2b wrote:

was this just a random thought you came up with???

Not really

I just happened to be working on one of the fleet vehicles and came across yet another of the lousy GM caps.

I cussed the manufacturer all day and came back here to remind everyone.

I'm not sure if it had been posted here before?

The guys at work think they are doing me a favor when they do their own repairs. Most try to use good parts, but the OEM dealer parts are not always the best choice

a2b · Post by **a2b** » Fri Aug 01, 2003 4:13 pm

yes, OEM parts are not the best choice all the time. and you are right. i dont think its been discussed here

Pat · Post by **Pat** » Fri Aug 01, 2003 6:04 pm

I also read the topic about Dex-Cool do we need a specific cap for this.

Jim · Post by **Jim** » Fri Aug 01, 2003 6:19 pm

Pat wrote:I also read the topic about Dex-Cool do we need a specific cap for this.

And what pressure?

Post by **HenryJ** » Fri Aug 01, 2003 6:22 pm

Pat wrote:I also read the topic about Dex-Cool do we need a specific cap for this.

I would say just look it over carefully, there are many reputable companies making good caps out there.

Ask your trusted parts person which cap they would recommend, then examine it. I'd avoid the 99 cent special.

Look for a smooth rubber seal that has an area with good coverage on the filler neck. (the rubber may crack with age, but usually out lasts other cooling system parts)

The ones with the pressure relief lever can be handy for checking the pressure, or lack there of, before opening.

My stock cap was marked 15 lb. I replaced it with a 16 lb. cap.

I would not go less than 15 lb , and would probably hesitate a bit at 18 lb. (plastic tanks which are usually pressure tested to no more than 18 lbs.)

smokinjoe · Post by **smokinjoe** » Sat Aug 02, 2003 10:28 am

good stuff

quickbiker · Post by **quickbiker** » Sun Aug 03, 2003 4:15 pm

Pat wrote:I also read the topic about Dex-Cool do we need a specific cap for this.

Yea, one that don't let air in or leak.

Retep · Post by **Retep** » Fri Jul 23, 2004 5:38 am

I just bought a Stant 11230 16 lbs. radiator cap.
My concern is the upper gasket is a much smaller diameter than the gasket on the stock cap. It looks like it should seal, but just barely.

I will have to keep an eye on it.

Stant's web site specifies a 10230. The parts store didn't have it and someone on zr2.com recommended using the 11230 so that is what I bought.
Adavance Auto Parts web site also calls for the 11230.

Pete

rmzl · Post by **rmzl** » Wed Jul 28, 2004 10:37 pm

Just changed my cap last week. Got the GM one (# RC92 ??). It was labeled for dexcool and most important, the small valve in the middle of the cap (the one that gets the coolant back from the overflow) has a spring as opposed to the traditional design which is a loose valve.

check this link for recomendations, found it quite intresting.

http://www.imcool.com/articles/antifree ... cs2001.htm

MACS 2001: GM and Texaco “Bare All” about DEX-COOL®
by I.M. Cool
Appeared Jan/Feb 2001 Cool Profit$ Magazine
© 2001 All Rights Reserved
As in the past, the MACS 2001 Convention and Trade Show in Orlando provided some very interesting and helpful air conditioning information. However, the sleeper presentation at this show was not about refrigerant, but—of all things—engine coolant! (Sleeper does not refer to making you sleepy; it was anything but boring.)

Marketing departments of major consumer goods manufacturers are known for their attempt to conceal even a shred of negative publicity about their products. You can’t blame them; you do the same in your business. That’s why it was refreshing to witness a candid GM/Texaco presentation about DEX-COOL coolant and its related field service problems. I give the big guys credit for even bringing up the subject because, well, let’s face it, there are not a lot of kind words being spoken about this coolant at automotive service shops today. (Especially at radiator shops.)

GM Cooling System Contamination Video @ $10 +S&H - Call 800-393-4831Left: 14-Minute GM Training Video is now available to help technicians service known cooling system contamination problems in specific GM vehicles.

GM’s Jay Dankovich and Equilon Enterprises’ (Texaco) Stede Granger directed a 2-year study of thousands of DEX-COOL cooled vehicles. Armed with the results, they really didn’t have anything bad to say about the coolant. In fact, they strongly defended the product’s reputation. What they revealed to the audience is that specific models of GM vehicles have specific cooling system contamination problems. And essentially, that DEX-COOL is not the culprit!
Their presentation started with a 14-minute video that is now being circulated to technicians at GM dealers nationwide. In the video, GM’s trainers succinctly described the problems that have been found and the corresponding corrective actions to be taken by technicians.

Suggestion. This video is a “must see” for all technicians considering themselves antifreeze/coolant experts. Without this information, your cooling system service knowledge of late model GM vehicles is severely limited. Seriously!
Fortunately, you can buy the video for only $10 (plus S&H). Call MSX International of Auburn Hills, Michigan at 800-393-4831. Ask for the DEX-COOL Video: “Understanding Radiator Cap and Cooling System Contamination.” Part number: RADCAPK. Immediately following this article is a report on this training video by John Brunner, recently retired GM field service representative.

What was said at the presentation? Besides the video, Jay and Stede included their personal observations about the study. At the end, they fielded several questions from the audience. Here’s a recap of their entire presentation.

1. Keep the cooling system filled. In fact, fill the reservoir bottle to “Hot” level when the system is cold. Problems arise when a system’s coolant level is not maintained. (Fleet vehicles receiving regular maintenance, and with reservoirs kept slightly above normal, do not show signs of contamination. This even applies to the specific “problem” vehicles.)

2. The coolant problems found in this survey were caused by system contamination, and not due to the breakdown of DEX-COOL.

3. Check and keep the pressure cap clean and functioning. A contaminated and/or malfunctioning cap causes low coolant levels, which in turn causes overheating and a greater loss of coolant: the notorious vicious cycle. No matter what the vehicle, if the cooling system acts suspiciously, test the pressure cap.

4. On the ST vehicle models mentioned in the GM DEX-COOL video, you “must” replace all suspect radiator caps, especially those with a Drop-Center design, with a Stant Model 10230 or 11230 (Spring-Center type). (Just do it.)

5. Make sure that the coolant is at a 50-50 mix. Often, the flush water was not being removed from the engine block. Consequently, when a 50-50 mix is added to the system the resultant mixture could approach 30-70. Like any fluid that has been diluted beyond its recommended levels, the lowered level of inhibitors will not be able to protect the coolant system effectively. Low levels of inhibitors can cause pitting on aluminum surfaces and general corrosion of cooling system metals.

Cutaway of Drop-Center CapLeft: Drop-center, “vented” radiator pressure cap. GM found this cap (like the Stant 10231) to be less helpful than a Spring-center cap (shown below) in controlling the formation of contaminants in the cooling system. If contamination forms, the debris fouls the valve and restricts its ability to seal. In turn, the coolant boils at a lower temperature. Coolant loss is accelerated and so is the accumulation of contaminants.

Cutaway of Spring-Center CapLeft: Spring-center, sealed radiator pressure cap (like the Stant 10230). This is the preferred cap for GM applications that are more prone to accumulating cooling system contaminants.

6. A safe method of achieving a true 50-50 mix is to first determine the actual capacity of the system (use the owner’s manual). Then add 50% of “that” amount of undiluted DEX-COOL (or any coolant), and top it off with water.

7. Mixing a “green” coolant with DEX-COOL reduces the batch’s change interval to 2 years or 30,000 miles, but will otherwise cause no damage to the engine. In order to change back to DEX-COOL however, the cooling system must first be thoroughly drained and flushed.

8. Bacteria cannot live in a hot, Ethylene Glycol environment and is therefore not a threat to DEX-COOL.

9. While there have been intake gasket failures on CK Series, V8 powered vehicles for various reasons, DEX-COOL has never been found as a cause.

10. Use a refractometer to check the condition of DEX-COOL. Its inhibitor package is strong enough that if the batch still provides proper freeze protection, it is probably still providing proper corrosion protection as well.

11. DEX-COOL can handle the minerals in hard water better than silicated conventional chemistry coolants. Drinkable water is suitable for top off.

12. In ST Blazer applications where the radiator cap is mounted at an angle to the ground, the vehicle is more susceptible to radiator cap contamination and its related problems. The Stant 10230 is a wise choice for these vehicles.

regards.

Post by **HenryJ** » Thu Jul 29, 2004 3:43 am

rmzl wrote:Just changed my cap last week. Got the GM one (# RC92 ??). ...

Does it still use the fiber gasket, or rubber?

IMO, the gasket was a contributing factor. It has an inside diameter that is very close to the same as the radiator neck. When the gasket shrinks a little it can shift off center allowing air contamination.

rmzl · Post by **rmzl** » Thu Jul 29, 2004 10:31 pm

Ummm..now that you mention it, I kinda though the gasket was strange looking, but I'll have to check it and get back to you later. (wife's got the truck!!).

rmzl · Post by **rmzl** » Mon Aug 02, 2004 10:28 pm

The cap's # is RC 82 and the bigger/upper gasket is probably fiber but the lower one is rubber.
I'm keeping an eye on it and on the coolant level, looking good for now

CrazyChaz · Post by **CrazyChaz** » Wed Aug 04, 2004 1:40 pm

I also picked up the Stant 11230 16lb cap at Advance Auto Parts. Its seems to fit just fine for me, plus im not to worried the package also says it fits 10230 applications.

Retep · Post by **Retep** » Thu Aug 05, 2004 6:15 am

CrazyChaz wrote:I also picked up the Stant 11230 16lb cap at Advance Auto Parts. Its seems to fit just fine for me, plus im not to worried the package also says it fits 10230 applications.

Yeah, I think it fits ok too. I don't recall the package saying it would fit 10230 applications. I will have to look. I think I still have the package laying around. I am glad you noticed that though. That makes me feel better about the cap.

Pete

Jim · Post by **Jim** » Sat Sep 11, 2004 2:16 pm

I'm hoping this one is the hot lick...

Jim · Post by **Jim** » Sat Sep 11, 2004 7:55 pm

Then I saw this on the S-10 Planet.com forum

Dexcool was developed specifically to protect aluminum engines. As any engine that is primarily made from aluminum the key word here is "primarily". The engine still has lots of small parts touching the coolant that are made from ferrous metal. Stuff like bolts, the water pump impeller, headbolts, gaskets, cylinder bore liners, etc.

The protection level of silicated coolant is dependent on a coating of silicate on all of the parts of the engine blocking electrolytic reactions. This is a hit-miss kind of thing and you can see the effects of electrolysis on the intake manifolds on mid-80's Oldsmobiles and Chevys. They will be eaten away wherever they were in contact with a ferrous metal part. The way Dex-Cool functions is that it actually changes the mollecular structure of the surfaces of the aluminum in contact with the coolant. (Sometimes this will appear as a black or dark gray coloring of the aluminum inside the cooling system.) This is a similar process to bluing of ferrous metals to prevent rust.

The drawback of silicates is that over time they flake off leaving unprotected areas of the engine open to electrolytic action. They also have hard debris floating around in the cooling system. (The Silicate coating is that white flaky stuff you see in a used engine block at the junkyard.) Pieces of it find their way into the water pump seal and wear it out much earlier than if you use Dex-Cool. They also build up in the radiator and block the flow of coolant through the tubes slowing cooling. And as if that were not enough, the silicates act like insulation keeping heat from transferring from hot parts to the cooler liquid and from the hotter liquid to the cooler radiator surface to be carried away.

Dex-Cool has had some issues with solids forming in the coolant. Those issues are caused by two things.
1. Air trapped in the pressure side of the cooling system.
2. Over-concentration of coolant.
You can mix them but you lose the benefit of the Dex-Cool (mixing is not what turns the coolant into "mud") Never go higher than 50/50 and always make sure the system is full and is not losing coolant. Also, when you do this, replace the Radiator cap, preferably with a new one from GM. GM used to use Stant caps until they found out that they were getting air in the cooling systems from them. Look at your cap and if you see a Stant brand "Block S" on the stock GM cap, toss it and get a new one from a GM dealer. As long as it does not have that "Block S" on it when you pick it up, you are good to go. Some of them may have the small letters "TVS" on them, these are the good ones.
The NAPA cap has a block leter "S" stamped on it!

Post by **HenryJ** » Sat Sep 11, 2004 9:46 pm

It is the design that is flawed. read the Mac's article linked above.

Above: Drop-center, “vented” radiator pressure cap. GM found this cap (like the Stant 10231) to be less helpful than a Spring-center cap (shown below) in controlling the formation of contaminants in the cooling system. If contamination forms, the debris fouls the valve and restricts its ability to seal. In turn, the coolant boils at a lower temperature. Coolant loss is accelerated and so is the accumulation of contaminants.

Above: Spring-center, sealed radiator pressure cap (like the Stant 10230). This is the preferred cap for GM applications that are more prone to accumulating cooling system contaminants.

I would say again that I have seen 20 yr old green coolant that never posed a problem even when subjected to air , and creek water.

Yet I have seen numerous cases of sludged , corroded, damaged parts , etc. in systems using Dex with very little neglect.

Glad I went green, and I'll never go back.

The extended life coolant was a good idea, but just didn't pan out in my book.

killian96ss · Post by **killian96ss** » Fri Nov 12, 2004 8:18 am

HenryJ wrote:I would say again that I have seen 20 yr old green coolant that never posed a problem even when subjected to air , and creek water.

Yet I have seen numerous cases of sludged , corroded, damaged parts , etc. in systems using Dex with very little neglect.

Glad I went green, and I'll never go back.

The extended life coolant was a good idea, but just didn't pan out in my book.

I also recently switched to green which IMO is far better that the orange dex cool crap. When I changed my coolant, it already had crap and debris floating around in the system. I only have 40k on my crew. If I waited the 5 years or 100k miles I'm sure I would have other serious cooling system problems. I found that the MACS link has good info for radiator caps, but all that BS about dex cool being perfectly safe is well ridiculous. Think about it, the 2 companies involved in the study are GM and Texaco. These are the makers of the orange crap, so of course they are going to say that all of the problems associated with dex cool are because of something else and not their coolant. I am also shocked that the article say that it's ok to mix the orange and green stuff, and that all that will happen will be reduced longevity of the coolant. BS, if you mix the 2 you end up with gell-o in your system which will clog up just about every small passage in your cooling system which will cause major problems. I have also personally seen too many cars and trucks with cooling system problems directly related to dex cool. It was a good idea, but GM needs to either develope a better coolant or just switch back to the reliable green stuff. I would suggest to anyone using dex cool to switch to green. The only draw back would be that you should flush your system every other year. I also like to add Redlines Watter Wetter which improves heat transfer and also has corrosion inhibitors.

Steve

2bunik · Post by **2bunik** » Fri Nov 12, 2004 2:53 pm

when you switch ... all you do is remove the orange stuff and replace it with the green ?????

killian96ss · Post by **killian96ss** » Sat Nov 13, 2004 7:27 am

2bunik wrote:when you switch ... all you do is remove the orange stuff and replace it with the green ?????

Yes, but make sure you flush the system thoroughly. It helps to use a flush kit like the one from Prestone which most auto parts stores sell. This is what I used recently to flush the orange crap out. I also took the overflow tank off and rinsed it out. I then filled the system with the green stuff and distilled water to achieve a 50/50 mix. I also like to use one bottle of Redline's Watter Wetter, or Hyperlube's super coolant for better heat transfer and corrosion protection.

Steve

Post by **HenryJ** » Sun May 29, 2005 5:30 am

This thread needed a bump to the top since there are still people running the stock GM radiator caps

rmzl · Post by **rmzl** » Tue Aug 09, 2005 6:45 am

Hi everyone,

Haven't added water to the truck since one year now!!!! (normal?)
Change your caps!

coffeedrnkr · Post by **coffeedrnkr** » Tue Aug 09, 2005 9:46 am

my friend wanted me to clean the throttle body on his mom's fullsize astro van with a 4.3 and after I got done cleaning it and got it back together I started it up and after I shut it off you could actually hear the cap sucking in air and when I took the cap off there was dex junk all crusty on the inside of it and the dexcool looked more like pondwater or something. I got them to go pick up a new stant radiator cap and told them to get it flushed but man, I thought that was pretty bad. its got like 120k and I doubt it has ever been changed.

I switched over to green a while ago and put on a stant radiator cap and I will never go back to dex.

F9K9 · Post by **F9K9** » Tue Aug 09, 2005 12:38 pm

So, which cap is the one recommended? Is the NAPA on shown in Jim's reply the correct one. I do not have a stock one on now but, I want to make sure I have a good one. NAPA, AUTOZONE and ADVANCE is what I have here locally.

Post by **HenryJ** » Wed Aug 10, 2005 2:18 pm

I use NAPA Balkamp part number 703-2462

It is the 16 lb. safety lever pressure relief cap.

It was just under $6 , my cost, today.

F9K9 · Post by **F9K9** » Wed Aug 10, 2005 2:59 pm

It "be" on my truck as we speak for $6.41 (they may have accidently forgotten sales tax on your, HJ due to your work account).

I actually think what I had on there was a little better but, O'Riely's (sp) is not a nationwide chain. The gasket that sits highest (when in place on the radiator) was a little wider on the one from NAPA.

If you want side by side shots of underside and top of caps, I will be glad to post them.

killian96ss · Post by **killian96ss** » Wed Oct 05, 2005 10:37 am

f9k9 wrote:If you want side by side shots of underside and top of caps, I will be glad to post them.

Do you still have time for these pictures? I really need to do this mod, but I see people here are using different caps from different mfg's, and I'm a little unsure about which one to choose.

HenryJ is using Napa cap part # 703-2462
Jim is using Napa cap part # 703-1446
CrazyChaz is using Stant cap part # 11230
rmzl is using GM cap part # RC92
Retep is using Stant cap part # 10230
f9k9 is using Napa cap part #703-2462 & was using O'Rileys cap part # ?

I know I need a 16 lb cap with a rubber gasket that covers the radiator opening better than stock, but which one is the best choice?

Steve

barch97 · Post by **barch97** » Wed Oct 05, 2005 12:20 pm

To further confuse your choises...

I'm using the same cap as CrazyChaz in my Sonoma (stant 11230)

and a Stant 10330 in my wife's blazer

Both are far superior fit and seal than the OEM cap.

F9K9 · Post by **F9K9** » Wed Oct 05, 2005 1:37 pm

killian96ss wrote:
f9k9 wrote:If you want side by side shots of underside and top of caps, I will be glad to post them.
Do you still have time for these pictures? I really need to do this mod, but I see people here are using different caps from different mfg's, and I'm a little unsure about which one to choose.

HenryJ is using Napa cap part # 703-2462
Jim is using Napa cap part # 703-1446
CrazyChaz is using Stant cap part # 11230
rmzl is using GM cap part # RC92
Retep is using Stant cap part # 10230
f9k9 is using Napa cap part #703-2462 & was using O'Rileys cap part # ?

I know I need a 16 lb cap with a rubber gasket that covers the radiator opening better than stock, but which one is the best choice?

Steve

I'll check when I get home. There's a box with what I thought was a thermostat but, is probably the cap laying on my desk. Will post if it's the cap.

F9K9 · Post by **F9K9** » Wed Oct 05, 2005 3:53 pm

Bad pictures but, the O'Rielly is a 15# Murray Ultra part# 7718. Both gaskets are rubber and the outer gasket extends out to the outer edge. The Murray has no lever to relieve the pressure while the NAPA does.

Post by **HenryJ** » Wed Oct 05, 2005 4:04 pm

The lever caps are handy for bleeding the air out of the system.
Squeeze the upper radiator hose to purgethe air to the expansion tank. Flipping the lever up makes this easy.

rmzl · Post by **rmzl** » Mon Oct 31, 2005 11:48 pm

Hi everybody,

Updating on my cap from last summer. The fiber upper gasket gave way, it was leaking very slightly and an orangy powder was forming around the edges. I found a rubber gasket in my toolbox which was quite thick and replaced it. I'm not sure how it will hold. I kinda like the stock look

with Dexcool sign an so on, so I'm waiting to see before getting one of those all metal ones.

Cheers.

rmzl · Post by **rmzl** » Tue Nov 08, 2005 6:20 am

Well guess what. My temp reading went up to 2 lines below 210 (where it was supposed to be, I guess). On long uphill stretches (and we have quite a few in my part of the world), it went beyond 210 and back down smoothly. Before changing the gasket, the gauge used to jump up and down beyond 210 before the fan engages. i always thought it was temp sensor related.
Any comments ?

barch97 · Post by **barch97** » Tue Nov 08, 2005 7:13 am

rmzl wrote:Hi everybody,

Updating on my cap from last summer. The fiber upper gasket gave way, it was leaking very slightly and an orangy powder was forming around the edges. I found a rubber gasket in my toolbox which was quite thick and replaced it. I'm not sure how it will hold. I kinda like the stock look with Dexcool sign an so on, so I'm waiting to see before getting one of those all metal ones.

Cheers.

that orangy powder is dehydrated dexcool. And, if fluid can leak out, air can leak in. Air + Dex = BAD

A flush and refill may be in order but at the very least, keep a close eye on that "new" gasket and the fluid level.

rmzl · Post by **rmzl** » Tue Nov 08, 2005 11:25 pm

barch97 wrote: Air + Dex = BAD

Tell me about it! I went through this already because of a bad intake manifold gasket. But I'm sticking to dexcool.
Although there was this leak, it seems I caught it on time because I haven't seen any sludge (yet

).
I topped the bottle and it seems the "new" gasket has made the cooling system perform normal again by keeping the pressure levels up.
I'll be watching the fluid level regularly for the next couple of weeks.

killian96ss · Post by **killian96ss** » Sat Nov 12, 2005 8:52 pm

Well I just replaced my stock cap with a Prestone cap, part # RSP-31. This is a 16 lb cap with the relief lever. I did notice something interesting on the stock GM cap during the swap. My stock cap definitely has rubber seals on the top and bottom.

I thought the whole reason to switch caps was because the stock cap's upper seal was fiber instead of rubber.

Mine isn't.

The upper rubber seal on my stock cap is actually wider and thicker than the Prestone cap I replaced it with.

Both seals on my stock cap were in excellent condition.

Maybe GM made 2 different caps?

Steve

barch97 · Post by **barch97** » Sun Nov 13, 2005 3:13 am

Are you sure that was the "OEM" cap? are you the original owner? maybe someone beet you to it?

killian96ss · Post by **killian96ss** » Sun Nov 13, 2005 9:15 am

barch97 wrote:Are you sure that was the "OEM" cap? are you the original owner? maybe someone beet you to it?

I am not the original owner, but when I bought my CC it only had 6k miles, and I doubt the cap was changed as everything else was completely stock. I will take the cap to my friends house today and get some pics with his digital. The cap is made of black plastic and has orange writing on it.

Steve

04crewvt · Post by **04crewvt** » Sun Nov 13, 2005 9:47 am

saw this thread a week or so ago and since i am stuck with low cost/no cost upgrades right now i grabbed a stant 11330 ie carded 10330 at wally world. Changed out factory cap and noticed that it was a spring vent center and both top and bottom seals are definitely rubber. maybe they finally got it right at the factory for the 2004's Yellow and white markings and dex-cool logo on it with a part # of 15066479. Guess i will keep it as a backup.

killian96ss · Post by **killian96ss** » Sun Nov 13, 2005 10:37 am

The top of my stock cap in orange letters says NEVER OPEN HOT, CHECK LEVEL IN BOTTLE, < TVS >, 15 LB CLOSED SYSTEM, ALIGN ARROW AND VENT TUBE Both upper and lower gaskets are definitely rubber. My CC is an 01, but I bought it in 02. I guess it's possible that the dealership replaced my cap with a newer style GM cap.

Steve

green02crew · Post by **green02crew** » Tue Nov 20, 2007 2:04 pm

Mine is stock and also rubber. Mine is an 02. No idea how I got a rubber one either as I also had Dex-Cool when I got it.

Torskdoc · Post by **Torskdoc** » Tue Nov 20, 2007 7:37 pm

I just replaced mine too with a lever-vent. Original cap had rubber 'gasket/seals on upper/lower surfaces.

Black Plastic Housing cover over metal, Multi-lingual, "NEVER OPEN HOT" Radiator graphic with "Dex-Cool" printed underneath, Part # 15066479
(2002 CC 4.3L)

Had some MINOR sludge on it, so soaked it in DISHWASHER Detergent overnight. Scrubbed with a soft bristle brush, good as new. Keeping for a spare.

Larry

ethanehunt · Post by **ethanehunt** » Mon Nov 14, 2011 1:24 am

I was having overheating problems with my '95 Windstar (3.8L) after having a rebuilt engine put in ~40k Miles ago. Not believing the local mechanic that the head gasket was gone again (no milkyness to oil; no white smoke on start-up), my GF suggested the rad cap. I googled "why change rad cap" and came across this article. So we said why not...I haven't overheated since.

Post by **HenryJ** » Mon Nov 14, 2011 5:51 am

Interesting. So you were not over heating then. Your system was purging and not recovering the coolant from the expansion tank? Or perhaps you were over heating due to air in the system?

S-10CREWCAB.NET

Radiator cap

Radiator cap

Re: Radiator cap

Re: Radiator cap