Tools for Yanmar 1GM10

[JumbleDuck]

Also, some Yanmar bolt heads are NOT metric standard e.g. 9mm af on 6mm threads.

I think they do this so you can use different spanners on each side of a nut and bolt combo. So, for example, the alternator pivot bolt has a 12mm head but the nut has a 13mm head, so you can undo it without needing two of any size of spanner.

 

[blackbeard]

If your water pump is anything like mine, I confirm that the bolt heads for the impeller cover need a 7 mm spanner, and it's best if your spanner has both an open-ended and a ring spanner ends.
Also if your installation is anything like mine (hard to get at) the spanner for the anode cover plate needs both ring spanner and open-ended spanner ends (8mm, from memory). An extensive vocabulary also helps.

 

[Halo]

Best thing I ever bought for yanmar engines is a Kennedy adjustable "C" Hook Wrench. It makes the fuel filter a breeze

 

[De.windhoos]

These days I just remove the raw water pump to change the impeller. Getting the cover plate of/on with the pump in place is a PITA.

 

[Tranona]

These days I just remove the raw water pump to change the impeller. Getting the cover plate of/on with the pump in place is a PITA.

Suggest you fit a Speedseal which will solve the problem of removing the cover. Much easier than removing the pump with the risk of damaging the screws.

 

[ghostlymoron]

On my 2GM20 i had to unbolt the water pump, twist it on the hoses and could then access the cover. Very poor and lazy design.

 

[Tranona]

On my 2GM20 i had to unbolt the water pump, twist it on the hoses and could then access the cover. Very poor and lazy design.

Very different from the 1GM though, which bolts through the timing cover on the front of the engine. Lovely cocktail of bronze aluminium and steel.

 

[De.windhoos]

Yes. Same problem on my 3GM30.

 

[Topcat47]

Lovely cocktail of bronze aluminium and steel.

Or not, depending on how you view it. It's surprisingly easy to wreck the timing cover.

 

[Tranona]

Or not, depending on how you view it. It's surprisingly easy to wreck the timing cover.

Yes, been there. Saltwater leak left the cover like the surface of the moon and the screw heads like a piece of cheese. All repairable, though with a bit of ingenuity.

 

[nemodreams]

These days I just remove the raw water pump to change the impeller. Getting the cover plate of/on with the pump in place is a PITA.

Yep - easiest way.
But - be careful when first removing - the original bolts are flange head, not the best things for spanner grip !. Swap them for normal hex head stainless same size + spring washers - and liberal copper grease. Your life then is easy !
There is no gasket involved - it has a substantial O ring to seal against timing case. Easy to replace - just check the large slot + lug are in the same direction. ( you can feel the slot easy that the pump engages into ) Crank runs clockwise - water pump anti clockwise ( facing timing case )

It takes a couple of minutes to have the pump sitting on the cabin table !
Which is a civilised way to insert an impellor !

The pump will wear out - it needs to come out someday for service. If those bolts are stuffed when you 'do' need it - you have a problem !

 

[Topcat47]

The bolts are also relatively soft and easy to round off. I had to buy a set of bolt gripper sockets to get mine off this winter. +1 for SS replacements.

 

[dave_gibsea]

Replace water pump bolts with stainelss ones. Most common spanner sizes on 1GM are: 10mm 12mm then 13mm and 8mm, the large sump plug/oil strainer is 19mm. - rings and 3/8" sockets are best (not the 19mm sump one though, that needs 1/2" drive).

 

[Tranona]

Yep - easiest way.
But - be careful when first removing - the original bolts are flange head, not the best things for spanner grip !. Swap them for normal hex head stainless same size + spring washers - and liberal copper grease. Your life then is easy !
There is no gasket involved - it has a substantial O ring to seal against timing case. Easy to replace - just check the large slot + lug are in the same direction. ( you can feel the slot easy that the pump engages into ) Crank runs clockwise - water pump anti clockwise ( facing timing case )

It takes a couple of minutes to have the pump sitting on the cabin table !
Which is a civilised way to insert an impellor !

The pump will wear out - it needs to come out someday for service. If those bolts are stuffed when you 'do' need it - you have a problem !

Even easier if you fit a Speedseal cover plate!