Anyone find a replacement pulley, or new bearing, or part number I can use to replace this pulley? It puts up quite a racket at higher RPMs and I've tried different tensions to no avail.

 

The idler is still available new from Mazda. The part number is N249-15-940. They aren't cheap but not available anywhere else.

 

Ahh, so I'm guessing it's this one? That's a steep price.

https://www.atkinsrotary.com/store/8...49-15-940.html

After rebuilding the pump, replacing the leaking low pressure lines, and flushing the system with ATF type F I still have some whine which I thought was the pulley but it could be air still in the system. I've been turning the wheel back and forth lock to lock but it's not going away.

 

Could you pick out a bearing with the same dimensions and press it in?

 

Yes, that's the pulley that I found on the Mazda parts fiche. To test it, remove the belt and spin the pulley by hand. The bearing should be quiet with no play. If you can hear considerable bearing noise then that bearing is bad. You could always buy a known good one by post a want to buy ad here on the forum and save a few bucks. I'm sure someone has one laying around that's good.

The whining could be the pump itself. The pump could be worn. Just take that into consideration as well.

 

Well I just rebuilt it, and compared to the internals of a junk pump I have, this one was immaculate on the inside, no scoring or anything. I dunno, maybe I should just loop the lines and remove it.

 

Were you able to test the bearing in the pulley?

 

Car hasn't moved. Been busy working on my truck. I have one other pulley, from salvage motor, I can try too. Might have some time this weekend.

 

If you can press the bearing out (get creative with a vice and some sockets) you may find that the bearing ID# is a common part and your local place can get you a new bearing to press in. I had to do this with a LandCruiser idler pulley and it was no problem at all. It's not like Mazda - in their infinite wisdom - chose to use some obscure bearing diameter and construction that nobody else uses. The bearings are usually only about $5-6 when they're available locally. Good luck,

 

Thanks, I drove the car yesterday. It's quiet below 4,000 RPM, but when I rev it up and shift, as the RPMs drop I hear a high pitched whine. Thought it was the pump or pulley but my wife thought it was maybe just the belt. Maybe I'll take a video. It's not loud, but it's there. I'm going to double check belt tension before I head out for the day today.

 

Loose or worn belts WILL cause a squeal at higher rpm's. I would check the tension and the belt condition before buying a new bearing or pulley. A bearing usually makes a groaning or growling noise when failing, not a squealing.