Cub 149 Loader - hydraulic issue

[CADplans]

Originally Posted by Merk

I have set of PF Engineering loader plans. PF Engineering is calling out 3/4 (-12) fittings on the suction side. They also recommend a pump with an 4 to 8 GPM.

This might be an area to look at. If my memory is working right a suction filter and high pressure filter are different.

8 GPM is mighty high,,,

A hydraulic strainer kinda looks like "coarse" window screen,,
the filter is typically capable of stopping a 10 micron particle or larger,,

so, the filter is too small to "suck" through,, hence the window screen strainer.

Most strainers are designed to screw into a 1 1/4" or 1 1/2" coupling,, that puts the strainer in the tank.

Keeping the suction line short makes it easier for the pump to suck oil from the tank.

This is referenced at the beginning of the movie "Beverly Hills Cop II" and the discussion of 50 feet of garden hose and a golf ball,,,



In the lower right of this pic, you can see the strainer screwed into the yellow coupling that is welded to the side of the square tank.

[cooperino]

Originally Posted by Palskidoo

Suction line size is 1/2" and the pump suction side is JIC-8. I did find an issue where I had trapped some air in the system so I added a vent to let the reservoir breathe.

JIC-8 is 1/2. What size line do you have on pressure side? I would use 3/4 hose with an adapter to the JIC-8.

[Palskidoo]

Originally Posted by cooperino

JIC-8 is 1/2. What size line do you have on pressure side? I would use 3/4 hose with an adapter to the JIC-8.

i am using 3/8" line on my pressure side.
My pump has sae-8 fittingon the suction side. Would using a 3/4" line adapted to use JIC-8 (1/2") flow any better than using 1/2" line with JIC-8?

thanks

[Merk]

Originally Posted by Palskidoo

i am using 3/8" line on my pressure side.
My pump has sae-8 fittingon the suction side. Would using a 3/4" line adapted to use JIC-8 (1/2") flow any better than using 1/2" line with JIC-8?
thanks

What is the thread size on the suction side of your pump?

by cooperino
IC-8 is 1/2. What size line do you have on pressure side? I would use 3/4 hose with an adapter to the JIC-8.

I would want a 3/4 inch line in the whole suction side. You still have a restriction even though you are using an-8 to -12 adapter.

What make and model hydraulic pump are you using?

Does the suction side have a hose designed to use as a suction hose?

I've been watching this topic wanting to learn a few things. I was taught to ask if you don't know. Since it's closed system I like to start somewhere. The hydraulic sump-suction system looks to be a good place to start.

[Merk]

Originally Posted by Palskidoo

Hello Everyone,

Been lurking in the shadows here for a while as I built my loader assembly onto my 149. I started with PF Engineering plans (thank you to them!) and changed a couple things.

ggrin2:

What changes did you make?

[CADplans]

Originally Posted by Palskidoo

i am using 3/8" line on my pressure side.
My pump has sae-8 fittingon the suction side. Would using a 3/4" line adapted to use JIC-8 (1/2") flow any better than using 1/2" line with JIC-8?

thanks

The length of the hose is VERY important,, also,,,

If the suction line is 4 inches long, 1/2" is probably big enough,, 24 inches, 3/4" is probably OK,,

If your pump is 6 GPM or more, and the suction line is 4 feet long,, you may need a 1" ID suction line,,

How long is your suction hose? That kinda dictates hose inside diameter,,

What type of hydraulic oil did you use? That matters a lot also,,,

a 10W oil will flow easier than a 30W oil,,,

[Palskidoo]

UPDATE

so after trying some different setups:
-filter on return line
-bigger suction line
-changing the location where return line meets the reservoir

I finally made some progress!! I got a lot of help from a local mechanic/ hydraulics guru and we determined my issue came from my design. Like i mentioned before my design started with the PF Engineering plans (thanks again to them!) with some changes. My major change was to connect the each up-right of the loader to the sub frame for additional fluid capacity. However based on my suction and return locations air in the fluid would be stuck in solution without a chance separate out before being sucked into the pump again.

So i plugged 1 upright and only use the sealed subframe and opposite upright for my reservoir. I relocated the return to the upright, instead of the subframe. this now allows the returning oil to "relax" and then drain into the subframe; where it can then be sucked back to the pump.

I am making some more modifications to the setup and finishing up on the bucket but i should be tooling around with the tractor-loader soon!