Can any one go into detail about check valves? What are the signs one is bad or dirty? How do you go about changing one? Where are they located?

Thanks

It all depends on what type of machine as in brand and model .I can help you if you give me this information

98 Putz 36

There are different types of check valves. The most elemental type is like a ‘one way only’ sign. The oil is allowed to flow > but not < thru a line, like a diode. Some are pilot operated. They have to be told when to open by pilot (signal) oil; like a difference in pressure across two ports. This difference of pressure allows the main valve to open and flow. It is sort of like a horn relay in an electric system where the small amp load closes contacts for a larger load. There are check valves that are pressure sensitive to a given value.

A defective check valve will either leak or not close or open with an other than required pressure.

I hope this is the type of information you were looking for. I am sure that if you Google “check valves, or hydraulic system components” or some combo you will get a very detailed answer. ;~)

On a Putz They are located on the ends of the differential cylenders that allow the oil to be removed from the loop line and are for smooth change over . if your cylenders are banging hard they may need to be changed .but make sure you have new ones first ,because you will lose a lot of oil if you don't

Thanks SS, That sounds like what I have going on. Bangs a little on one side. I will order new ones on Monday. Are they are the U shaped things in front of the water box? How common is it to have to change them?

When the check valves go bad, you will also probably notice an increase in hydraulic oil temp. as well. Also, listen for a hissing noise, that is usually the best giveaway that a check valve needs replacing, due to the plunger not opening completely, you will hear the oil bypassing, "hissing", and the check valve itself will be hot as hell also. It isn't a very common thing to replace them on a regular basis, they usually will last quite a long time, but like anything else mechanical, when it breaks, it breaks for good.

Check Valves are funny things they are very durable IF you keep your oil CLEAN these have a tendancey to get stuck with trash once in a while and they do wear out .after you change them I like to take the old ones apart look at the spring look at the spool inside and out look at the seat you can tell a lot about the oil condition and the valve by looking inside them I have seen everything from a grain of sand to paint chips .This is why it is critical to work clean when changing these fittings please pressure wash the area first before changing them out .by the water box area can be very oily and dirty .Hope this helps

If you need help with your Putz give me a call. 303-762-0708 ext.124 Chances are good that the check valves are all fine.