Coolant and Bars Leak use in 99 SLS

[Bill A]

On my 92 and 96 I always used the Bars Leak Powder or GM pellets sealant when dealing with replacing or refreshing the coolant.

Just got this 99 SLS and no pellets are mentioned in owners manual section on coolant and I have no access to a 99 service manual yet.

Am I correct in assuming I should use the sealant when I referesh the Dexcool on the 99 as I did on 96 and 92 models.

PS - Anyone have a set of 99 GM Seville service manuals for sale?

Thanks

Bill A

[JimD]

....Am I correct in assuming I should use the sealant when I referesh the Dexcool on the 99 as I did on 96 and 92 models.

Yes.

My '98 has a decal under the hood that gives the part number.

[Ranger]

GM quit using them at some point around 2000 I think. After changing the coolant on my wifes '96 Bonneville and seeing the muck build up on the cap, I too have quit using them.

I had a set of '99 manuals, but shipped them to Stephan in Germany earlier this year. Have you checked Ebay?

[thu]

It looks like GM started using them again beginning at least in 2003. The 2003 FSM states, "This engine uses DEX-COOL and GM coolant supplement (sealant) P/N 3634621 specifically designed for use in aluminum engines. Failure to use the eengine coolant suppplement (sealant) and the approved coolant antifreeze could result in major engine damage. When refilling the cooling system, add three pellets of the engine coolant supplement sealant GM P/N 3634621 to the lower radiator hose."

Then it goes on to say that this engine does not have coolant engine block drains and that when draining the cooling system, 2.5 quarts of coolant will remain in the engine block.

[Bill A]

It looks like GM started using them again beginning at least in 2003. The 2003 FSM states, "This engine uses DEX-COOL and GM coolant supplement (sealant) P/N 3634621 specifically designed for use in aluminum engines. Failure to use the eengine coolant suppplement (sealant) and the approved coolant antifreeze could result in major engine damage. When refilling the cooling system, add three pellets of the engine coolant supplement sealant GM P/N 3634621 to the lower radiator hose."

Then it goes on to say that this engine does not have coolant engine block drains and that when draining the cooling system, 2.5 quarts of coolant will remain in the engine block.

Thanks to those who replied.

I will continue with the sealant in the 99. Have used it on two Sevilles with no problems over 8 years.

I like to refesh the coolant once a year at least. Drain the all I can out of the petcock and refill with new and add the sealant to the upper hose.

Bill A

[thu]

I don't think you'll want to add the sealant to the upper hose. You'll want to add it to the LOWER hose.

[Bill A]

I don't think you'll want to add the sealant to the upper hose. You'll want to add it to the LOWER hose.

Thu,

Over the years on this forum I have heard to put it in: a) the top hose, b)the bottom hose and c)put it in both.

I did it in the top hose numerous times with no problems but that does not mean it was "correct procedure".

The 96 GM service manual does say lower hose.

Bill A

[Ranger]

I believe "technically" the lower is correct, but either will work. Just don't put then in the surge tank unless you dissolve them in premixed coolant first.