Changing coolant

[hiljak]

I'm going to change the stock coolant in my 1999 STS with Dexcool. I've read people talk about adding Bars stop leak pellets also. How many should I add?

Is there any technique to flushing the coolant system?

[JasonA]

Install two tubes of the Bars Leak golden seal, or either three of the six pellets in the package of GM Cooling System Tabs, or all six of them. The package says only use three, but using all six is just fine.

To drain the coolant, access the petcock on the radiator, if you can reach it. I can't get to it on my '97. I put down some cling wrap on the ABS module to keep it from getting wet, and remove the two 10mm bolts that bolt the lower hose to the water pump housing. Only the top half of the engine will drain that way, but do that once now and once again in the fall maybe, and you can be sure you'll get most of the old Dexcool out.

[Ed Fenwick]

Aloha,

What I did was: Open the petcock on the bottom drivers side of the radiator. Let all the old coolant come out. If it looked uckey then fill and drain again. If you arn't going to change the thermostat, refill the radiator and warm up the engine to get the coolant out of the block and heater. Drain again, close the petcock add the whole package of pellets (5) crushed up into the radiator, not the overflow bottle. Fill the radiator with 50/50 anti freeze coolant and clean water. Cap the radiator, fill the overflow bottle to the cold mark and let the engine warm up. Check the coolant level until you are comfortable that it is ok. I think that the Northstar engine may have a different recovery bottle.

Good luck Ed

[Ranger]

Ed,

This is a '99 Northstar. There is no radiator cap. The cap is on the surge tank.

You should be able to get most of the coolant out by removing the lower hose. Then you can blow out whats left by reversing the hose on a shop vac (put it on the exhaust port), then stick it in the surge tank and use your hand to seal it.

[bc6t]

I am contemplating doing this on my 1998....from what I have read (search the archives) you should use a 50/50 mic of dexcool and distilled water and place the pellets (crush them first; 3-6 pellets) in the lower hose NOT inside the rad housing itself. It sounds pretty straight forward....

Good luck.

[cdictas]

Gentlemen,

I need to change out my coolant in my 99 STS. I have read almost all of the posting concerning this subject. I was going to have my dealer do this job for me, because its messy but I can't imagine the tech using distilled water. So I'm going to tackle this job myself. With this in mind, I still have a couple of questions.

1. I haven't look yet, but isn't there a petcock on the bottom of the radiator on a 99?

2. Why do I have to remove the lower radiator hose (assuming there's a petcock) to put the bars gold leak sealer in the line. Why can't I just crush the pellets and add it to the premix of dexcool and then fill the system through the surge tank?

Thanks,

Chuck

[Bill K]

1. Yes there is a petcock but I couldnt get to it even after removing the lower panel. Removing the lower hose is just much easier.

2. The tabs will circulate through the system better being added in the lower hose. I'm not sure you can crush them fine enough to get through the fill tank hose. Maby you can. Since I already had the hose off to drain the fluid it seemed goof proof to add them then.

[Scotty]

I never understood why they make it so difficult to get to the petcock, I have even seen people fabricate tools to get at it.. I guess it is much easier and faster to remove the lower hose.. good idea

While we are on the topic of hoses, I noticed a couple of wear marks from a bracker on my upper hose but nothing too serious. I have a 96, when do you suppose it would make sense to replace the upper and lower hoses to prevent the possibility of a problem that would leave you on the side of the road?

[cdictas]

Bill K,

How many pellets did you put in the hose and did you break up the pellets?

Chuck

[cdictas]

Mike,

It's been my past experience if the hoses appear to be swollen and plyable that their best years are behind them.

Chuck

[Ranger]

No need to break up the pellets. Just put 4-6 of them in the easiest hose to get to (usually the top hose). I wouldn't add them to the premix as they may not flow well enough into the system and clog the return line. It may work but why take the chance. The upper hose is not too bad to get at.

I just did the coolant on my daughters '99. The drain plug is accessable through a small hole in the lower shield on the drivers side but you can't get it to turn it. A pair of reeealy long nose pliers might do it, if you had a pair that long. I used a block of wood (it was what was available) and cut a slot in the end of it to engage the wings (somewhat like a wing nut) of the plug and used that to turn it open and closed. I did this at her house so there were not a lot of tool available. I just cut two slots with a hand saw and used a screwdriver to chisel out the remainder. It was crude to say the least but it worked great.

[95SLS]

Hey, I notice post about wear on top Rad Hose from bracket, I also noticed that B4 going on a trip. I put on a new hose and found a sponge that was sticky on one side, I put that sucker at the wear spot and 50K later she's doing fine.

I even took the old hose out of the trunk!

That was bad design eh?

Mike

[bigjayzway]

Use the pellets from your local dealer. The price is almost the same, and they work a lot better.

Definately put them into the hose, and not in the tank....You will run into problems if you do.

Big Jay

[JohnnyG]

Yes, there is a petcock drain on a '99, it was not made that easy to get to because the idea was that it would only need to be done once every 5 years. If you want to open it, cut a 1/4" wide slot in the end of a 12" piece of broomhandle (wood), you can stick the handle into the small hole in the plastic underpinning, up through the rad support, and onto the petcock, or remove the plastic entirely...it's pretty easy.

NEVER put the sealant into the surge tank, it could plug up the tiny hose which comes from the tee in the upper crossover, it is placed there at the highest point in the engine so that any air in the cooling system would be bled off to the surge tank. If it gets plugged, your hosed, in fact it should be checked when you do the coolant change.

NEVER put the sealant in the upper rad hose! The flow is from the upper hose into the radiator, and you don't need the sealant there (where it could possibly plug radiator passageways) you need to get the sealant into the BLOCK. This is best accomplished by putting the stuff into the lower rad hose which is the suction side of the water pump. The flow from the lower hose goes straight into the block.

ALWAYS use distilled water and 50/50 mixed Dexcool. The premixed is a good idea. Do NOTHING to alter the 50/50 final mix, don't "double flush" with water, don't hook a garden hose to the car, NOTHING! Just drain and refill. (that's PERIOD)

[Ranger]

Bigjayzway,

The Barsleaks tabs or powder are the exact same thing you get from the dealer. Bars makes them for GM.

JohnnyG,

I can't beleive it makes any difference what hose you put them in. They are going to break up in water and flow through the entire system anyway. I have done mine and my duaghters in the upper hose and have yet to have a problem. I recall once giving the numbers on coolant flow in gallons per minute. I can't remember what they where but it was high. Point being, I don't think you are going to plug anything up unless your water pump is slipping badly no matter where you put it, unless of coarse you're about to tell me to put it where the sun don't shine. Then all bets are off.

[JohnnyG]

Just telling the story the way Guru told it...lower hose for the reason I quoted.

[Ranger]

Guru has said lower but has said either on many occasions as evidanced below.

http://caddyinfo.ipbhost.com/index.php?sho...77&hl=barsleaks

http://caddyinfo.ipbhost.com/index.php?sho...barsleaks&st=15

[BigCat83]

I'm a novice to Cadillacs and the Northstar.

I just bought a '97 Eldorado and I've owned an '83 Jaguar XJ-S V12 for several years (quite a ride!). I'm no novice when it comes to cars and exotic engines (I am the ONLY person who goes near my XJ-S with any tool whatsoever!).

The only thing that goes in the XJ-S cooling system is fresh coolant and distilled water every 18k to 20k miles. ANY sealant in the Jaguar's cooling system is a disaster that WILL happen.

I humbly ask you fellows who are are far more experienced in these fines autos than I: Why cooling system sealant in the Northstar cooling system?

Thanks,

Roger

[JimD]

....

I humbly ask you fellows who are are far more experienced in these fines autos than I: Why cooling system sealant in the Northstar cooling system?

Thanks,

Roger

Insurance.

Aluminum castings are prone to small (as in microscopic) imperfections that can be a nuisance in water jackets.

And the recommended material is not a "sealant"; it is an organic "supplement" that only adds a level of protection against potential coolant loss.

Best $5.00 you ever spent.

[BigCat83]

Makes sense...

I'll get some of these tablets.

Thanks Jim,