96 Park Avenue Coolant Leak

[ka9mgd]

I have a coolant leak at the bottom o-ring on the belt tensioner that is aluminum with a rubber o- ring on it.It was leaking about 6 months ago and I installed a new o-ring and used a dab of silicone sealer on the o-ring.It has started leaking again.I used a mirror to see that is where it is coming from and not dripping from someplace else and running down from another area such as the heater hoses or intake seals.Is this o-ring a special part? What type of sealer should I use when inserting a new o-ring;silicone or form a gasket sealer?

[HotZ28]

The O-ring should be "Viton" due to the coolant & metal parts rapid temperature changes, chemical exposure and longevity. You should never use any sealant of any type, only silicon spray to ease assembly, unless of course your aluminum is pitted or corroded, then you will need a new tensioner assy!

[ka9mgd]

Thanks for the reply.I am having trouble locating the correct part number for this o-ring.Can anybody help with the correct part number?It is the o-ring that surrounds aluminum not the plastic outlet that comes out the other side.

[HotZ28]

Shown below is a pic of the tensioner with a black arrow pointing to the O-ring I think you are trying to describe. Is this correct?

[ka9mgd]

Yes Sir that is the one that is leaking.

[ka9mgd]

gmparts supplied me with the part number 24502846.Thanks for the picture and reply Hotz-you the man.

[HotZ28]

http://www.gmpartsdirect.com

GM PART # 24502846
CATEGORY: Drive Belt Tensioners
PACK QTY: 5
CORE CHARGE: $0.00
GM LIST: $2.81
OUR PRICE: $1.66

[ka9mgd]

Thanks again Hotz.You the man.I received the o-rings in the mail and installed one yesterday.I am keeping my fingers crossed and will keep an eye on it to make sure the leak is fixed.I cleaned off the old sealant and polished the aluminum parts off with steel wool and yes I used a magnet to retrieve any residue left behind.I used a little oil on the o-ring only before re-installing the tensioner.