Water pump on Jinma Y385 engine.

[Johnny P]

Hello all,

Hope you are all keeping safe from the virus. My water pump on my tractor developed quite a substantial leak. I have removed it from the tractor and made a couple of new gaskets, inner and outer ones. I tested these and on closer inspection it looks like the leak could be coming from the ceramic graphite water seal behind the belt pulley.

Could anybody tell me how to remove the pulley please?

Thanks
John

 

[piper184]

From the parts diagram it looks like the pulley just slides onto the shaft. Take the nut off the end and it should come off. It may need some persuasion as in tapping or worst case use a pulley puller or shop press. It should not be on that tight unless badly rusted. Use your favorite penetrating oil and let it soak if you think it is rusted.

 

[Johnny P]

Thanks for the reply piper184. There does not appear to be a nut on the end of mine (see photo). The round part on the end of the pulley appears to be part of the casting. I tried some mole grips on it but it would not move hence my previous thought. I also tried using some pulley pullers, again no movement. I didn't want to apply too much pressure in fear of causing damage. Do you think if I soak it with penetrating oil the pully would ease off? I cannot see how it would just be put on the shaft with out any mechanical fixing.

Thanks

John

 

[Bob Rooks]

Thanks for the reply piper184. There does not appear to be a nut on the end of mine (see photo). The round part on the end of the pulley appears to be part of the casting. I tried some mole grips on it but it would not move hence my previous thought. I also tried using some pulley pullers, again no movement. I didn't want to apply too much pressure in fear of causing damage. Do you think if I soak it with penetrating oil the pully would ease off? I cannot see how it would just be put on the shaft with out any mechanical fixing.

Thanks

John

The holes in the pulley are threaded, correct? It's an interference press fit, soaking with penetrant won't do any good. A simple H-bar puller will pull it off (use grade 8 or metric class 8.8 or 10.9 bolts & washers for puller bolts. Make sure the threads of the puller bolts extend into the pulley hub as far as possible, and that the H-bar is perfectly parallel to the face of the pulley hub. Oil the puller threads. A little heat on the pulley hub may also be required. Also, the pump must be disassembled to reinstall the pulley.

 

[piper184]

Hmm, that does not look like the pump in my parts book. I will have to take a look at the one on the tractor to see what matches mine.
I was thinking of a steering wheel puller, which is almost exactly like the one Bob mentioned. You may be able to find one that can bolt onto all 4 holes. Perhaps you could make one with a plate. Drill holes to line up with the pulley, weld a couple of nuts stacked together in the center. The trick will be finding a good quality bolt for the center. I would use a grade 8 fine thread with as large of diameter as practical.
As Bob said, if it is an interference fit, penetrating fluid won't help. That was based on my parts drawing showing a keyed shaft to pulley connection that had a nut on the outside of the pulley.
Let us know what you find and post pictures of the disassembly and repair if possible. All valuable info for the next person with a leaking pump.

 

[Bob Rooks]

I just replaced the coolant pump on my Mitsubishi excavator's K4E engine. Same-O. The pulley and fan hub is pressed onto the shaft. This is a very common practice.

 

[Affordable]

Good luck finding that seal, we have the complete water pumps and gaskets in stock, if you get tired of messing with it. We have shipped to France before ,Confirm its a Y385T engine, as the KM385 looks almost identical but uses a different water pump

Tommy
Affordable Tractor Sales Co
"Your Jinma Parts Superstore"
www.affordabletractorsalesco.com
979-865-4002

 

[aesmith]

I bought a replacement pump from Ali Express. It's a bit ridiculous that shipment cost as much as the product itself but it came to $88 all in, for water pump, hoses and carriage. It would have cost £315 for the pump alone from the UK agent.

 

[Johnny P]

I bought a replacement pump from Ali Express. It's a bit ridiculous that shipment cost as much as the product itself but it came to $88 all in, for water pump, hoses and carriage. It would have cost £315 for the pump alone from the UK agent.

Hello aesmith. Thanks for this info. I was looking at Ali Express but was suspicious of the price. Didn't know if they took your money and you never saw the product, you hear of these kind of situations. Nice to hear from some one who has dealt with them.
John

 

[Johnny P]

Hello all,
I got the pulley off. This gave me the view of the outer seal. I poured some water in to the pump. Holding it so the shaft faced the floor I noticed water leaking out of the "weep hole". I believe this means that the internal seal (ceramic graphite) must have failed. I managed to get the pulley back on by pressing it on in a big vice. The photograph shows the weep hole.

John