Wednesday, January 23, 2008

General Motors Compressors - Locked Up Out of the Box

You just bought a brand new, or remanufactured, General Motors type compressor (HR6, HT6, R4), and it's locked up staight out of the box! ...Or is it?

GM compressors have Teflon piston rings on the end of each piston. R4 Radial compressors have 4 pistons, and 4 Teflon rings. HR compressors have 3 pistons, with a Teflon ring on both ends, so 6 Teflon rings total.

These piston rings are pressed onto the end of the pistons with a die, then quickly installed in the compressor cylinders during assembly. Quickly, because these rings expand or 'flex', trying to return to their original shape.

Once installed in the compressor cylinders, these Teflon piston rings will expand, and form a kind of positive seal. While very tight, the compressor is not locked up.

Another way to think of it is with a jar or, say grape jelly. While very tight, the lid is not locked onto the jar. You just need some assistance to open it the first time, maybe a rag or your shirt tail. Once opened, the lid is forever easy to remove.

The same goes for your new General Motors A/C compressor. With the use of a tool called a 'spanner wrench', available for sale or rent at most auto parts stores, you'll have the extra leverage to get that compressor rotating in no time.

No comments: