PISTON PUMP

[IRONMAN (AL)]

I have a 640 with a piston pump it appears to be leaking from the gap between the head (prime plug) and the body. Can i replace just that gasket or do I need to replace all the gasgets. The pump works fine it just has a prety good leak. When I take the head off what will happen, do springs balls and pistons go everwhere. Thanks for the help

 

[souNdguy]

do you have a service manual?

 

[IRONMAN (AL)]

I have a shop manual for the x00 and x01 tractors it shows the break down of the pump and the gasgets just reading it and doing it is sometimes different. wasn 't sure if i could replace the leaking gasget only or were the springs comming out when i take the head off

 

[ErnieD]

So when the head comes off 6 balls and 6 springs come loose. Inside there is a philips screw holding a plate with 6 more balls and springs. The plate in my pump was stuck in with gasket cement. Had to bake the head to release.

There is no tremendous spring pressure. You want a clean well lit place to work. A vise helps hold the pump. You will drop a ball or spring. Newspaper or a clean floor and a magnet will help. The plate has a notch that is aligned with the manifold stud for reassembly.

It would not hurt to keep the pistons if removed in the same sequence for reassembly. I did not and two were sticky. I played with order to match with bores.

Baking the head caused to oil to char, pretty much ruining the ball checks.

I made a check seat puller out of a bent spike and used the vise and a small socket to install the new seat.

Disassemble and then order the parts you need from this site.

 

[36 Coupe]

I use a shallow cardboard box when taking things apart on the bench.Keeps things from rolling away.We call them beer flats.My wife use them to hold seedlings in peat pots.Stores will give you all you can carry.