Rebuilding 4JHE Raw Water Pump

[kev_rm]

This is not nearly as sexy of a topic as adding used oil to diesel, but:

I have a Yanmar 4JHE circa 1989

I believe the water pump">raw water pump is this one

I've not rebuilt one of these before, but I want to do it as I have seepage in the ports behind the impeller housing (and the full replacement is~USD1000) , and I want to have spares to be able to do it again while abroad / at sea.

Is a press or other special tools needed?

Any words of wisdom if you have done this one before?

[Bycrick]

You didn’t say which 4JHE you had. But you might take note of the fact that Yanmar will sometimes list exactly the same pump for two different engines, under two separate part numbers, and with greatly different prices. Parts for older engines seem to be more expensive even if the identical part is used on a newer engine and sold for a lower price.

[a64pilot]

I know of only two 4JHE’s the 4JHE and the 4JH(B)E. I have the (B) version, only difference is the transmission shaft angle. Mine is an 87.
These pics are of my spare pump. I have not taken one apart though, it differs from the one you linked to in that there is a nut that holds the gear on.
I would assume that gear may need a puller, but that’s just guessing.
Shop around, I don’t remember what I paid, but I don’t think it was $1,000.



Of course I have had my pump out and it does have a nut on the shaft.

[a64pilot]

Overhaul kit isn’t cheap either and I’d assume may even include a shaft, I’d call them Mon and ask
https://shop.toadmarinesupply.com/ma...sectionid=5669
This dealer price is $758
https://www.marinedieselparts.com/st...umps_3jh2e.htm

However I did find the pump you linked to being sold on EBay for $950 and it said it was for a 4JHE and did plainly have the bearing on the end of it where I have a nut.

I’d either pull my pump and look if I were you, or call a Yanmar dealer, perhaps based on serial number there could be two different pumps.

[kev_rm]

I think there is only one "4JHE", at least one without other letters. Its the 40hp version, N/A.

Originally Posted by Bycrick

You didn’t say which 4JHE you had. But you might take note of the fact that Yanmar will sometimes list exactly the same pump for two different engines, under two separate part numbers, and with greatly different prices. Parts for older engines seem to be more expensive even if the identical part is used on a newer engine and sold for a lower price.

[Wotname]

Hmm... if it was me, I pull just pull it apart and assuming the shaft isn't scored or badly worn, then source the bearings and seals from your local bearing shop. A pump shop should have the impeller but in the worst case, get a Yanmar one.

All the smaller Yanmar pumps that I have stripped down use commercially available of the shelf components.

You might need a gear puller but a small hammer, a drift and some blocks of wood will usually suffice.

If you can't get the lip seals with a SS garter spring, just remove the existing carbon steel garter spring and replace it with a suitably sized O'ring.

The bearings and seals might cost $20!

[GordMay]

Yanmar Service Manual - 4JHE, 4JH-TE, 4JH-HTE, & 4JH-DTE
➥ http://sagaforumet.com/yanmar-manual/4JHE/manual.pdf

Cooling Water System ➥ http://sagaforumet.com/yanmar-manual...kapittel_6.pdf

[Windcall]

Have to ask this question. Did you remove the motor mount, or did you file enough clearance to get the bolt out. I lucked out, found a brand new one at a Marine Consiment, and I forgot where it is in the boat!!

[kev_rm]

GordMay, you are the bomb, I have been looking all over for this.....

thanks!

Originally Posted by GordMay

Yanmar Service Manual - 4JHE, 4JH-TE, 4JH-HTE, & 4JH-DTE
➥ http://sagaforumet.com/yanmar-manual/4JHE/manual.pdf

Cooling Water System ➥ http://sagaforumet.com/yanmar-manual...kapittel_6.pdf

[Bill whitmore]

Just remove the entire pump and replace it---in the end it will be both much easier and cheaper because it is no just a matter of replacing the seals...the shaft will be damaged for sure---simple job to remove and replace!

[a64pilot]

Originally Posted by Windcall

Have to ask this question. Did you remove the motor mount, or did you file enough clearance to get the bolt out. I lucked out, found a brand new one at a Marine Consiment, and I forgot where it is in the boat!!

Was this for me? I have no clearance issues, the pump is easily accessible and my mounts are of course stock Yanmar mounts

[kev_rm]

Why do you think the shaft is damaged?

Originally Posted by Bill whitmore

Just remove the entire pump and replace it---in the end it will be both much easier and cheaper because it is no just a matter of replacing the seals...the shaft will be damaged for sure---simple job to remove and replace!

[sailcrazy]

Following....our 4JH-TE needed an impeller replaced, and we ended up pulling the whole pump to get it done. Unfortunately, the paper gasket between the pump and the block proved the hardest part to get!

[Jim Cate]

Originally Posted by Bill whitmore

Just remove the entire pump and replace it---in the end it will be both much easier and cheaper because it is no just a matter of replacing the seals...the shaft will be damaged for sure---simple job to remove and replace!

This has not been my experience with similar pumps. If it is just seeping the shaft is likely quite all right. However, even if it is scored, a Spedi-Seal sleeve will restore the surface and last for hundreds of hours at the least.

I do not see how this could not be less expensive than buying a ~1k$ replacement pump. I won't argue about the "easier" notion.

Jim

[a64pilot]

Still, for $250 for a Yanmar rebuild kit, surely that contains a shaft for that kind of money