Write-Up: Replacing Accessory Belt Tensioner

The 24502846 has to be the heater hose connections O ring.

OK, so looking the thread over, GM 24502375 is the correct O ring for the heater hoses.  It is nearly 22 mm inside diameter.  I ordered 2 from Amazon.

The 24502846 is the O ring for the single nipple on the tensioner that goes into the timing cover.  To summarize, the GM part numbers for the O rings needed are,


24502375 for the two heater hoses (2 needed)

24502846 for the tensioner (1 needed)

15-34066 for each end of the elbow (2 needed)

So I finally got all the O rings I needed for the job. I took my time and it went well with just one snag. I couldn't get one of the heater hose fittings off the old tensioner. I hit it with liquid wrench, tapped it with a hammer, but it wouldn't budge. The other one twisted off, but lower one, no go. I ended up undoing the pinch clamp on the hose, and worked it loose and off. I then removed the tensioner. I put it in a vice and carefully hack sawed a slim section of the tensioner around the fitting. That enabled me to spread it a bit, and I was able to twist it out with a pair of vice grips. The O rings were flat, and I could barely tell they were there. I picked them out with an awl, and cleaned the fittings. Popped the new O rings on, brushed some grease on them, and they slid in and sealed. I used new GM O rings on the Dorman aluminum elbow, and they sealed as well. No leaks. I am a happy camper.