MF 35 Hydraulic Pump rebuild

[jtwthaxj]

Hey guys, I have my pump out and on the bench, I have replaced all of the o-rings everywhere, and the piston rings on the pump. But I cannot get the piston rings compressed enough to get them back into the valve chambers. What is the best way to do this?

Thanks.

J

 

[banjodunn]

G'day remove the rings from the pistons and check them in the bore, I did one recently and had to file all the end gaps to get them in. Good luck



Jon

 

[trout250]

can you use a ring compressor similiar to the one that is used to do piston rings on an engine

 

[gengine]

Baileys has a real nifty tool for small pistons.
Bailey's - Piston Ring Clamp Set
This works great on small engines such as chainsaws. Good luck!

 

[suffolkboy]

Hey guys, I have my pump out and on the bench, I have replaced all of the o-rings everywhere, and the piston rings on the pump. But I cannot get the piston rings compressed enough to get them back into the valve chambers. What is the best way to do this?

Thanks.

J

should go in easily, just pinch with your fingers and apply gentle pressure, i have done thousands and they never cause a problem getting in. Good Luck

 

[shona13]

G'day jtwthaxj .
Funny handle!!
Step ONE, Never as has been suggested use a cylinder hone on the valve chambers if the chambers are scored or worn REPLACE them.
Step two.Fit the both pistons to one chamber WITH THE MACHINED FACE OF THE PISTON FACING OUT,Use pair of internal circlip pliers and GENTLY Squeeze the ring ,using the circlip pliers you can see what you are doing normally as said the rings go in easily
then gently pull one of the pistons out a little bit any one and put a 1/4 bolt between the piston and the valve chamber what this does is extend that piston a little bit and allows you to install one piston at a time then you wont break any rings.
Next fit ALL O rings to the pump end plates this done oil and fit the pump camshaft then the camblock making sure it is the plain one with no grove.
With the pistons and chambers assembled slide the osilator ring in between the two valve chambers with the arm facing down .
Next fit the control valve spring tube as a complete assembly,then the other camblock with the grove making sure the oscilator ring fits in the grove,then the top end plate making sure ALL O RINGS are fitted install the retaining nuts/bolts and tighten.
turn then pump round and reassemble the control valve using plenty of oil.
Happy days.
Hutch.
.