Flushing Hydraulics

Okay, my used scissors jack assembly came from Crysteel today. It is basically everything I need for a dump bed. Pump,control,reservoir,scissors w/dual action cylinder,prefab hinge, PTO driveline, & hoses. Everything's sitting on a pallet.

The problem is they didn't cover the ends of the hydraulic lines with plastic & rubber bands. So now there's gunk in the ends of all the hoses.

What is normally used to flush hydraulic systems? Because of the quantity of gunk there is NO way I'm going to assemble it first, then flush it like normal. I want to flush it now, disassembled, to make sure everything is clean before I assemble it.

I know nothing about hydraulic systems as far as what's safe & what will destroy the seals. Kerosene, gasoline, specialty products? Anyone familiar with flushing individual components?

Also, the pump is a Williams 888 built into the reservoir. The control valve is built in as well. Does anyone happen to know the specs on this model? I've searched & searched but can't find anything about it. What I mainly want to know is direction of rotation, gallons per minute, and where to find replacement parts such as seals.



The pump & control is on the reservoir up front. This photo is from Crysteel & the reservoir is facing the wrong way to see the pump. I'm just wondering if anyone here recognizes this type of setup & could provide some specs for me. Thx.

Crysteel is bussiness I start there , find the model number give them a call most manufacture are more than happy to help out IMO

Take the hoses off and first blow some compressed air through them. Then run some gas through them to get out what's left. More than likely the grime didn't make it past the hoses and into the cylinder and or pump. Just check the other ends of the hoses once you get them off to make sure it's clean on that end.

About all I can tell you on the pump is to do a google search and see what comes up.

ditto

i would blow them out with air then flush with trans fuild .gas can dry the seals outthe rubber used in fuel line is different than in hydraulic lines fo a reason.also if you dont get all the gas out it can break down the hydraulic fluid when you fill it back up.trans fluid is hydro oil with a detergent in it if some if left over it wont hurt anything and actually will help keep thing clean

tm america said:

i would blow them out with air then flush with trans fuild .gas can dry the seals outthe rubber used in fuel line is different than in hydraulic lines fo a reason.also if you dont get all the gas out it can break down the hydraulic fluid when you fill it back up.trans fluid is hydro oil with a detergent in it if some if left over it wont hurt anything and actually will help keep thing clean

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I agree with using automatic transmission fluid for the flushing of your system.

You can use a lawn sprayer (the same type used for brake pressure bleeding) filled with ATF to power flush the lines.

So an air supply & tranny fluid takes care of the hoses before assembly. What about the pump, reservoir, control valve & ram? Should I wait until it is all assembled then flush it?

i would use trans fluid on everything fill the res shake it up then bump it out fill pump with atf turn it by hand till you are getting fluid out the pressure side then you are good to go there .doing it by hand wont hurt if some grit goes through it since it wont be under pressure it will find the easy way outcontrol valve i would blow it out while working it then fill with atf .i would just fill the ram with atf work it by hand then drain it i wouldnt blow air in it since it will force it to move rapidly and might hurt you since the forces will be great even with just 125psi of air

tm america said:

i would blow them out with air then flush with trans fuild .gas can dry the seals outthe rubber used in fuel line is different than in hydraulic lines fo a reason.also if you dont get all the gas out it can break down the hydraulic fluid when you fill it back up.trans fluid is hydro oil with a detergent in it if some if left over it wont hurt anything and actually will help keep thing clean

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Gas will not hurt hyd lines for just flushing them. There are no seals in hyd lines to worry about either. Trans fluid will be ok also but IMO gas is a much better solvent. Any gas left in the lines will evaporate in short order so you won't have to worry about contamination .

To each his own but I've done this probably 100s of times with no ill effects.

Unforgiven said:

So an air supply & tranny fluid takes care of the hoses before assembly. What about the pump, reservoir, control valve & ram? Should I wait until it is all assembled then flush it?

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About the only way to completely clean a hyd cylinder is to disassemble it. They are very hard to completely clean through the ports. As long as it looks as if none of the crud entered the cylinder I wouldn't worry about it.

better to be safe than sorry and there is no way to completely flush it anyway but having some atf in there will keep cleaning it even when things are running .most hydraulic cylinder have teflon rings in them and gas drys them out and will make them wear quickly or could leave a residue that could cause them to leak right off the bat.i rebuild transmissions for a living they are basicaly big hydraulic systems .even the residue from the soap in the cleaning machine will wear out the seals quickly if not fully removed.gm had service bullitins on this problem on the 4t60 and 4t60e transmissions they advised polishing the bores after cleaning in the machine .but if you can keep it from getting in there in the first place you wouldnt have to worry about it

These are all good points. I think I'm going to synthesize everyone's suggestions. I'll clean the outside of the parts & the inside of the hoses with gas to get most of the nasty, caked on grease. Then I'll run atf fluid through the other parts that weren't directly exposed to gunk. The hand cranking of the pump is a good idea. I never even thought of that.

You'll have to wait a few months for pics of my install though. I have a rear-facing PTO issue to resolve before I can put it on the truck.

Unforgiven said:

These are all good points. I think I'm going to synthesize everyone's suggestions. I'll clean the outside of the parts & the inside of the hoses with gas to get most of the nasty, caked on grease. Then I'll run atf fluid through the other parts that weren't directly exposed to gunk. The hand cranking of the pump is a good idea. I never even thought of that.

You'll have to wait a few months for pics of my install though. I have a rear-facing PTO issue to resolve before I can put it on the truck.

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Sounds like a good plan .

agreed.you'll love having a dump on there i couldnt live without mine it was the first thing i did to my truck when i got it

I would drain everything you can out of the system and then set up a filtering system using a remote filter mount. BEFORE you put new oil in a system you should filter it. New oil is not clean enough out of the bottle. ...... No this isn't a wacko theory by a newby. I am Fluid Power Certified and have been in the industrial hydraulics world for 20 plus years. 12 with the largest manufacturer in the world. There is a lot to explain related to this so I will start with an important concept. generally you want to get to a certain level of cleanliness or particle size. There are ratings based on standard SAE tests to rate filter effectiveness. A filter can absorb so much dirt before it clogs and by-passes. Large industrial plants hire filtering trucks to flush their hydraulic systems down to a specific micron level. It gives a great increase in component life. Other companies start filtering knowing they will need to change their filter several times until the cleanliness level maintains the proper level, There are simple gauges to indicate when a filter is about to be clogged and go to by-pass

hi-revr, I don't doubt your credentials but I've never heard of anybody filtering hyd oil right out of the bucket. Maybe on some sort of high tech hyd system or aircraft but I've been around alot of hyd equipment and everybody just pours it right out of the bucket into the system.

How big of particles does new brand name oil have in it?

While it's a good idea to run a filter, most factory dump systems don't even run a filter.

I was thinking of putting in some kind of inline filter somewhere. Surely they make those for hydraulic systems?

I doubt if I will use the hydraulics more than a few times per year, mostly for hauling garbage to the dump. That's why I bought a used system instead of spending the money for new.

What about some kind of "coffee filter" over the reservoir tank as you add the hydraulic fluid for your out-of-bottle suggestion?

How did you manage to buy anything directly from Crysteel? I want to deal their hoists in my area, they said I have to buy from one of their dealers. we put hoists under deuce cargo boxes around here for landscapers and farmers. If you're looking for rear facing PTO accessory drives, email me jatonka@telenet.net JT out

m16ty said:

hi-revr, I don't doubt your credentials but I've never heard of anybody filtering hyd oil right out of the bucket. Maybe on some sort of high tech hyd system or aircraft but I've been around alot of hyd equipment and everybody just pours it right out of the bucket into the system.

How big of particles does new brand name oil have in it?

While it's a good idea to run a filter, most factory dump systems don't even run a filter.

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First the solution, use a hand crank oil fill pump but add a remote filter adaptor in line. Most of my response is relating to hydraulic systems in general. I'm trying to keep this simple for everyone's sake and admittedly most guys on here would never use anything enough to worry about serious ware that wasn't already there. That being said this will come to be more important as the newer generation of equipment becomes available to us. Hydrostatic drives and many newer valve bodies are very sensitive to particle size. I don't recall the exact amount of contaminate in new oil but it is significant enough to affect component life. Somewhere I have some specifics and will post when I find it.

Think of it this way......If a pump or valve has internal clearances of 20 microns and your filter is a 20 micron filter you will have ware in your component almost immediately. The reason is a 20 micron filter doesn't filter 100% and when the filter reaches a saturation point they build pressure and eventually by-pass internally. That means they ain't filterin' nothin'. Filters undergo SAE tests. Searching on the internet will reveal results. I researched filters two years ago for a tractor I restored. The highest rated filter readily available to the average person is Purolator's Pure One. Fram was one of the worst. The best thing to do is install a filter set up with a gauge that shows when the filter is full. There are hydraulic filters out there that go down to one micron. Normally they are used on new systems where component clearances are incredibly tight. They will have multiple filter set-ups. The first one maybe a 10 or 20 micron otherwise the 1 micron will clog too fast.

jatonka said:

How did you manage to buy anything directly from Crysteel? I want to deal their hoists in my area, they said I have to buy from one of their dealers. we put hoists under deuce cargo boxes around here for landscapers and farmers. If you're looking for rear facing PTO accessory drives, email me jatonka@telenet.net JT out

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They have a used/one-of-a-kind inventory link on their website. I didn't buy it new. I think they are glad to get rid of the "trade-ins." I just called the guy & asked for a shipping quote. He called me back a few hours later. Four days later it was in my garage. Total cost was $1250 to my door. That included shipping 600 lbs of steel across the country. I just didn't feel like piecemealing it together. Sure, I could have saved a few hundred $$ sourcing every part locally & welding up my own scissors frame. But I'm really not up for that much DIY when hoists are readily available. Everything's sitting there on the pallet waiting for me to clean it up and bolt it on.

I worked out the rear PTO problem. I found an accessory from one of the members here. But it might be a short lived upgrade b/c I'm really getting itchy to do a tranny swap.