Variable speed transmission

[J_J]

Gravy, Thanks for the effort, even though it didn't work as one would hope. If that pressure jumped to 25 psi, that ls an indication of filter blockage, from dirty oil, which I doubt, or the filter is over loaded. Let me interject a thought here, and not to be negative. Seems to me that if this would work with an input filter, some one long ago would have done it. I would not want you to run blown up filter material into your system.

Let me also add this observation, have you ever looked into one of those quick-disconnect? It is not a 3/8 hole for fluid to come out. Say it is actually 1/4, and you try to run 3000 psi through that orifice, how much pressure do you think would be on the tip. I don't know for sure, but it will be more than you realize. Now if this kind of pressure is going into the input side of the filter. I would expect bad things. Many hydraulic technicians have told me to use one size larger quick disconnect. For instance, if you are using a 3/8 line, use a 1/2 in disconnect. This will allow full pressure and volume.

I was hoping that this procedure would work out, and if it does, it would be good thing for all of us to be able to filter our system using the PTO circuit.

Have you noticed that the size of the hose going to the filter on the tram circuit. or the PTO circuit. they are very large, 1 in or more. a thought here would be to attach a larger hose to the PTO output line, say about 2 ft, then run the other end of the line to the filter. Maybe the pressure will not be so great. For instance, a pressure washer, at 1/4 in from the tip, there is enough force to blow your finger open, and about one foot from the tip. I can rinse my havds.

What micron filter were you using?

 

[Gravy]

JJ'

I definitely think the quick-connect is part of the problem. The cross-sectional area is a lot smaller than that of the hose. I also think the hose size and length (I'd guesstimate that there's about 6 feet between the connection at the lift arms and the return fitting on the tank) also affect the pressure readings.

I wish I'd read your post about discharging into a bucket before I ran the test, but that's hindsight. OTOH, since I tested at idle and with hot oil, I really don't think the filter blew. The loading should have been much less severe than starting a car engine with fresh, cool oil and a new filter.

I've been working with various pumps, hose, and piping in the 6+ years since I got out of the automotive repair business. Experience has shown me that just a few feet of pipe or hose run and a few fittings can have more effect on pressures than seems intuitively obvious to me. I'm thinking and hoping that that is what I'm encountering here.

25, 50 or even 100 psi pressure drop may be considered insignificant in a hydraulic circuit rated for 2500 psi. For PT, it may not have been worthwhile to go to the next size hose and fittings to reduce that pressure drop. The only way I can think of to tell whether the pressure problem is real or apparent is to put a gauge on both sides of the element and see what the pressure drop is across the element.

If I'm lucky, I'll find that the total pressure never exceeds the filter's pressure rating and that the drop across the element is well below 15psi.

If I'm not lucky, I'll go to Plan "B" (whatever that may be)... /forums/images/graemlins/crazy.gif

 

[Gravy]

Quick update: the gauges should ship in the morning from McMaster/Carr. That means they'll almost certainly be here by Friday afternoon. If I'd ordered before 9PM I'd probably have gotten them tomorrow. I love dealing with McMaster! /forums/images/graemlins/laugh.gif

If I get the new tires mounted on the motorcycle and get enough of the 96 Blue Rug Junipers planted, I may manage to take another stab at the filtration this weekend! /forums/images/graemlins/blush.gif

Gravy