I've been getting signs of this so thought take it apart and have a look. It's pretty easy to do. It would be a good idea to have a magnetic PH2 screwdriver around. I also replaced the cable clip on the exhaust outlet - big pipe on the top - with an 8mm fuel line pipe clip. Nothing fancy just the single wire type.
Unplug - important as it has a clock in it the solenoids are live even when the machine is off. Always worth checking on anything that doesn't have an on off switch.
Cut the clip off and ease the exhaust pipe away from the fitting
Look carefully at the earth lead spade connector. The is a little bit that "sticks out" of the receptacle just past the end of the blade on the solenoid. That needs to be pressed down to take the connector off. It's more like a short bump. The mains connectors are insulate but if gripped with electrical pliers over these bumps they can be eased off. No chance without.
Slacken the nut on top of the solenoid off a little if needed to ease screw driver access to the fixing screws and remove them.
Remove it. I marked the base with a marker pen on the side adjacent to the markings on the solenoid coil - just in case but other things mean it can only go on one way.
Look under the base. There are 2 plastic discs with low diameter tubes in them. Remove them. I used tweezers on the tubes. Might not be a good idea to press them too far in playing about but the can be levered out with a pin etc if not enough to grasp.
Remove the nut on top of the solenoid completely. When this is replaced don't do it up too tight. There is a washer under the coil and the nut has a flange which fits into the coil. Lift off the coil.
I then held the square base in a small vice. Other things could be used. Then undo the nut directly over the base. There is a plastic ring between the valve stem and the base. This needs to be done up firmly when it's refitted.
Lift off the valve stem. A plunger and spring will be left in the base.
Have a good look around for grot etc, I may have found a tiny trace at the ends of the solenoid plunger. So little hard to be sure.
That's about it other than getting it all back together so reassemble the lot.
Take the plastic discs and tubes. Put the tubes in place and press them in to their flanged ends.
Then put these back into the machine - tubes go into the tiny holes.
Then put the valve back in place feeling the discs into the 2 depressions.
Then refit the screws and exhaust pipe. Tighten the screws cylinder head style diagonally a bit on each side until they are firmly down.
I think mine was rather loose as it tilted as soon as I undid 2 of the screws. There was also a bit of discolouration around one of the holes in the casting in the machine. Could be that they shouldn't be clamped firmly down on the base but that would need checking with feeler gauges - dubious, @DavecUK
may tell you this is an odd way of sealing them. Usually there would be O rings in the depression in the base. I suspect that the tubes are for metering and lo the 3 way exhaust action seems to be better now but just based on one shot. This may be down to pressing the tubes in until the flange on them was against the plastic discs.
No buzz now. There is during infusion, probably down to the pump.
The other reason could be the coil. It is probably possible to buy those separately without too much of a problem. All of the bits in solenoids are available for some makes.
John
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Unplug - important as it has a clock in it the solenoids are live even when the machine is off. Always worth checking on anything that doesn't have an on off switch.
Cut the clip off and ease the exhaust pipe away from the fitting
Look carefully at the earth lead spade connector. The is a little bit that "sticks out" of the receptacle just past the end of the blade on the solenoid. That needs to be pressed down to take the connector off. It's more like a short bump. The mains connectors are insulate but if gripped with electrical pliers over these bumps they can be eased off. No chance without.
Slacken the nut on top of the solenoid off a little if needed to ease screw driver access to the fixing screws and remove them.
Remove it. I marked the base with a marker pen on the side adjacent to the markings on the solenoid coil - just in case but other things mean it can only go on one way.
Look under the base. There are 2 plastic discs with low diameter tubes in them. Remove them. I used tweezers on the tubes. Might not be a good idea to press them too far in playing about but the can be levered out with a pin etc if not enough to grasp.
Remove the nut on top of the solenoid completely. When this is replaced don't do it up too tight. There is a washer under the coil and the nut has a flange which fits into the coil. Lift off the coil.
I then held the square base in a small vice. Other things could be used. Then undo the nut directly over the base. There is a plastic ring between the valve stem and the base. This needs to be done up firmly when it's refitted.
Lift off the valve stem. A plunger and spring will be left in the base.
Have a good look around for grot etc, I may have found a tiny trace at the ends of the solenoid plunger. So little hard to be sure.
That's about it other than getting it all back together so reassemble the lot.
Take the plastic discs and tubes. Put the tubes in place and press them in to their flanged ends.
Then put these back into the machine - tubes go into the tiny holes.
Then put the valve back in place feeling the discs into the 2 depressions.
Then refit the screws and exhaust pipe. Tighten the screws cylinder head style diagonally a bit on each side until they are firmly down.
I think mine was rather loose as it tilted as soon as I undid 2 of the screws. There was also a bit of discolouration around one of the holes in the casting in the machine. Could be that they shouldn't be clamped firmly down on the base but that would need checking with feeler gauges - dubious, @DavecUK
may tell you this is an odd way of sealing them. Usually there would be O rings in the depression in the base. I suspect that the tubes are for metering and lo the 3 way exhaust action seems to be better now but just based on one shot. This may be down to pressing the tubes in until the flange on them was against the plastic discs.No buzz now. There is during infusion, probably down to the pump.
The other reason could be the coil. It is probably possible to buy those separately without too much of a problem. All of the bits in solenoids are available for some makes.
John
-
