Loader changed hydraulic filter now buzzing/(cavitation?)

[CrosbyFamilyFarm]

I opened the filter compartment to my 735 Ford loader and found nothing there but a fiberglass stick with a float attached that was about two feet long going vertically in the post and the remnants of a bic pen (yes. a bic pen). There wasn't even the hardware that attaches the filter. So I bought the filter and threaded a 3/8 rod through it and attached a couple of fenestrated washers to the top to hold it. Then I reattached the filter, filled the post with fluid and started it up. Now I'm hearing buzzing whenever I rev above idle. If I activate the bucket, the buzzing stops, but starts as I let off the lever and rev above idle.

Could the previous owner have taken out the filter in order to stop the cavitation (please let me know if this doesn't sound like cavitation)? Can this buzzing be from overfilling the fluid (I may have added a couple of inches of fluid too much)? Should I change out my washers over the top of the filter so that more fluid can bypass the filter?

Any advice?

 

[RickB]

Make sure one of the short hoses connecting the suction tube to the pump and filter head are not delaminated and collapsing.

 

[CrosbyFamilyFarm]

That is exactly what is happening. The rubber tube connecting the pump to the metal pipe is collapsing at higher RPMs. What does this mean and what should I do? Is this common?

 

[RickB]

Only when the hose has degraded and needs to be replaced. What type of oil did you fill it with?

 

[CrosbyFamilyFarm]

I filled it with Super Trac 303 Tractor Hydraulic Fluid. It is a cheap fluid, but my NH dealer said it would be OK.

 

[RickB]

If it meets the old John Deere 303 standard, it should be fine.

 

[CrosbyFamilyFarm]

It says it meets the standards for Ford, JD and a number of others. I'll replace that one section of tubing and post back. I should be able to by tomorrow when NH opens.

 

[boggen]

Make sure one of the short hoses connecting the suction tube to the pump and filter head are not delaminated and collapsing.

That is exactly what is happening. The rubber tube connecting the pump to the metal pipe is collapsing at higher RPMs. What does this mean and what should I do? Is this common?

ditto rickb notation.

check to see if there is a screen between tank (possibly inside tank) and inlet on pump, or some sort of valve or filter, or hyd oil cooler.

a screen could be clogged, if hyd oil cooler between, then possibly an air lock. if filter, then perhaps a bad filter if new, or filter itself is clogged, the filter may have some sort of by pass if filter gets clogged, and bypass is not operating correctly.

heck when you changed fluid, you may have in inadvertently cause something to come loose and is clogging up hose, and is causing the rubber hose to collapse.

what ever the issue it is, it is between pumps inlet, and the tank outlet were ya put hyd fluid in.

 

[CrosbyFamilyFarm]

Thanks for everybody's input. There are no apparent valves or screens in place. I also spoke with the mechanic at NH here in Conn. and he said that this will happen when the bypass mechanism isn't in place around the filter.

So at this link Official New Holland Online Parts Store and Online Parts Catalog for New Holland and Ford Tractors. I am missing parts 14, 15, 16, 17, 18, 19, and 20. Nobody around scraps old implements and NH said they couldn't get three of the parts. As I said I had replaced it with a bolt and a few washers with holes drilled in it as a make-shift bypass. I feel like I need to allow more of a bypass but still be able to prevent any packing that cuts loose from going down stream.

My options, I think, are:
1. bolt a screen to the top of the filter and remove the washers,
2. remove the filter entirely like the previous owner did
3. remove the filter and put a screen at the base, where the filter should be
4. hold the filter in place with a single cross bar, with no screen, allowing a large flow through.

My worries about the screen is that it will fall apart and head through itself. Any suggestions? questions? My wife is starting to roll her eyes at me because I've been working on this for so long.

 

[CrosbyFamilyFarm]

So I just removed the filter and cut larger wedges out of my washers that are in place of the relief valve system. Then I put a piece of screen between them and bolted it back together. Started him up and it seems like the cavitation is gone. I just didn't have large enough holes in the washers. If anyone sees a major flaw in this solution, please let me know!

Thanks everybody!