Jinma 284 water pump.... rebuildable??

qualsite · Feb 10, 2016

Bearings and seal out on my Jinma 284 TY385 Water Pump. Heavy duty water pump, but I can't figure out how to get to the bearings. Seems a shame to dump and spend $180 for a new pump when it's just a normal bearing and seal replacement. The pulley won't budge with a puller, and the impeller has two holes in the back, like they are made for a spanner wrench to unscrew it. It doesn't budge either when I try to unscrew it. Before I put it in the 20ton press, anybody know how to get these pumps apart to rebuild? If so, a bearing and seal number to replace the bad parts with? I'm sure that 20tons will get it apart, but not necessarily the way I want it to.

Winmac · Feb 11, 2016

I can't talk about your pump specifically but in general it is not a standard bearing, typically the shaft and bearing are an assembly (water pump bearing).
Generally the impeller needs to come off first to remove a snap ring, I've never seen a threaded on impeller, press fit and to lessen the chance of destroying it heat the impeller.

Are the bearing and seal available from jimma?

Hillside2008 · Feb 11, 2016

I had the same questions about a year ago. After much research on the net I found that a KML bearing # WB1530116-1 was a near perfect match. Then I contacted a few places and found that this bearing isn't stocked in Canada or the USA. The seals wouldn't be a problem to get. I also found that A&T Parts and Rebuilders in Tupelo, MS will rebuild the pump but, apparently, they machine it to a different bearing. I know this isn't the answer you were looking for but I hope it helps.

Harvey

qualsite · Feb 21, 2016

Got it apart fine, and found that a John Deere A-JD9212 bearing and AR62933 seal were able to work, with some modifications. The bearing works fine, except that it has a standard 5/8" shaft, rather than the 11mm shaft on the Jinma pump. Drilling out the impeller and pulley to 5/8 were easy. The seal seating diameter is larger than the OEM seal [which is not marked anywhere, and I couldn't find a seal anywhere to fit, particularly when going up to the 5/8 shaft size]. It was actually pretty easy to enlarge the seal mounting hole, using incrementally larger hole saws, then a stone in the die grinder. It took only 2 hours to rebuild the pump from the time UPS delivered the bearing and seal [I had already made some new gaskets]. Total cost to rebuild, about $32, which is much better than the $200 for the OEM pump, which still has questionable bearings in it. Hopefully the John Deere parts will be a little beefier and last longer.

halfton · Sep 5, 2019

My 2007 Jinma 254 w/TY385 water pump failed due to bad bearings just like qualsite. Using qualsite's excellent suggestion for bearing+seal this was my experience...
- John Deere bearing cost about $30 and fits in housing fine.
- Impeller and fan flange had to be enlarged to 5/8 using regular drill bit. Problem is that the press fit isn't really tight enough. I drilled and tapped for 1/4 set screws.
- The seat for the seal is way too small so I enlarged it using crude measures (I'd rather not talk about it). The seal is the tricky part. If I had different tools I may or may not have been able to get a nice water proof seal.

Results: It leaked like a sieve out of the weep hole...most likely because the seal leaked...leaking out the weep hole is the usual sign of a bad seal.

Next Experiment: What the heck, I've got nothing to lose here now. So figuring that the new JD bearing is sealed and doesn't need the water for lubrication anyway...let's just plug up the weep holes.
Results: So far (a few hours of summertime running), so Good (no leaks and engine is circulating water great)

Yeah, this is ugly but it works. This tractor is only used for mowing and pushing dirt around...it's not relied upon for production.
I hope that this helps someone. Thanks to qualsite for the initial legwork finding the bearing.