AC compressor pulley grooves

[expo]

I just had a new compressor installed on my v10 engined motor home. I believe the make of the new compressor is SANDEN as was the old one.

The mh is equipped with a 6 groove serpentine belt and the old compressor had a 6 groove pulley. The new compressor has an 8 groove pulley with the belt now riding on the inner 6 grooves.

Is this unusual for replacements to be larger? Will it do any harm like jump grooves?

Also, after 10 miles the new compressor has oil on it. Is this a leak?

I'm going to challenge the mechanic on this and don't want to be BSed to.

Any mechanics have an opinion?

Thanks for any advice.

[Richard S.]

After my compressor was changed I also had oil dripping down. Cleaned the area around and the compressor with a rag. One year later no oil drips.

[auto]

An compressor front seal may seep as it seats in. This should only take 50 miles or so with the ac on.
Too many groves may not cause a problem but I would not accept it if it were Me.

[EngineerMike]

The groove issue shouldn't cause a problem unless there is an alignment issue or if the grooves are of different sizes. IIWM, I'd run a caliper check on the groove width (take a reading across all 6 grooves top to top on the belt and divide by 5 (you are measuring 5 spaces), then measure 8 grooves valley to valley and divide by 7. Results should match. Then do a sighting across the idler pulley to the new 8-rib pulley to assure they fall exactly in line. If either test is off, then the 8-rib pulley will cause trouble before too long.

That's a functional test. As a general guess, I'd say the shop ordered the wrong unit and is trying to pass it off so they don't have to eat the restock charge.

[expo]

Thanks for the responses. I've been running the a/c and, after several wipe offs between tests, there's no more oil film on the compressor case-- so you guys were right on with that.

FYI....On the pulley groove discrepancy, I contacted the manufacturer, Sanden, who's customer service return emailed and was non-committal on whether the shop ordered the wrong pulley but they said:
1) there should be no problem running a 6 groove belt on an 8 groove pulley 2) but not an 8 groove belt on a 6 groove pulley.

Like they were talking to an idiot that couldn't figure out #2.

I'll still call the shop on it just to see what they say.

Since my first post, I found the small return line disconnected from the coolant plastic expansion tank and the tank almost empty. They had to take it off to install the pressure switch in the a/c.

[mrschwarz]

If it were me, I would be looking for the right pulley. If the original compress was a Sanden and the pulley was 6 groove, they obviously manufacture the correct one. In my mind, non-committal is the same as saying you got the wrong one. Just my opinion.

[tderonne]

Over the years Ford has used both 6 and 8 groove FEAD (Front End Accessory Drive) systems on the V10. I suspect Sanden simply supplies the 8 groove as a one size fits all solution.

[Gary - K7GLD]

It's more an application thing - undoubtedly SOME installations using that same A/C compressor have a different belt setup, and possibly more accessory devices running off the larger belt - the pulley on yours will work equally well on either setup, and as long as the actual groves are the same size and line up, no worries!