Testing Hydraulic hoses

[sierradmax]

This winter I'll be tearing into a Bobcat 763 by doing an engine & hydraulics overhaul. With the cost of hoses, is there a kit that can test hydraulic hoses? i.e., plug one end and an adapter to fit on the opposite end and test with an air compressor?

 

[J_J]

An air compressor does not have the potential to test hyd hose.

Manufactured hose are tested at , I believe 4 times the operating pressure on a batch of hose.

If they aren't leaking don't mess with them, unless you just want all new hoses.

Hoses life is different, based on how and where it is used. .

 

[oldnslo]

Look at the hoses, are there cracks in the cover, places where the cover has been chaffed or worn through. How old are the hoses? On mobile equipment the oil temperature and engine compartment frequently are at 200 degrees F or hotter. This deteriorates the hose quicker than running at 100 degrees F.

Most major hose manufacturers recommend replacing hoses every 6 years if used on a daily basis.

I suspect some of the hoses, espcecially the HST drive ones would be much easier to change with the engine and seat pan removed.

Roy

 

[sierradmax]

This is on a bobcat skid steer. Machine is 15 years old and has 3500hrs. I think If I'm diving this far into it, might as well open the wallet for all new hoses and o-rings.

 

[brain55]

This is on a bobcat skid steer. Machine is 15 years old and has 3500hrs. I think If I'm diving this far into it, might as well open the wallet for all new hoses and o-rings.

You must have some deep pockets, your opinion might change when you get the price quote for that. Personally I might limit that thought process to the "man I don't want to try to change this hose when the engine is in" hoses.

Brian

 

[CJONE]

My suggestion would be to replace the hoses that are hard to acess with the engine in and do the easy ones when you can. Remember ANYTIME you have a hydrostatic system open everything including the new hoses have to be spotless CLEAN. The startup on a hydrostat system is crucial also. If whoever repairs the drivemotors and pump does not give you a startup proceedure go somewhere else!! CJ

 

[J_J]

If you are going to replace all the hoses, then measure and write down the length, fittings required, and take that to a hyd shop and get an estimate.

Make several copies and take to several shops if available.


You might also send your list to DiscountHydraulicHose.com

You can also make up your own hoses using

Field-Attachable (Reusable) Hose Fittings > Discount Hydraulic Hose.com

To add to the original question.

Yes, you can test the hyd pressure using a good pump capable of producing at least, 3000 psi.

This pump would work.

If you have a log splitter with pump, that will work.

http://www.surpluscenter.com/item.asp?item=9-7762-D&catname=hydraulic

Pressure:
3190 PSI rated
3770 PSI peak
Speed:
2000 RPM rated
6000 RPM max.
Flow:
0.56 GPM rated
1.69 GPM max.

You can drive this pump with a 2 to 5 HP engine, and use a relief valve and needle valve. Just about every hyd system will see excessive high pressure at times.

Need a hyd tank, small one.

You should be very aware of what hyd fluid can do, so safety is standard practice.

 

[sierradmax]

I have the parts manual to the machine and they do list part numbers for each hose but unfortunately, they don't list their length. I'll probably see what prices they are from bobcat (probably most expensive) as well as climb inside the machine, measure and note each hose, and shop around for the best price.

 

[crazyal]

If you have a lot of hoses to do I would look into buying a basic hose crimper. You might find a used one on ebay with the dies you'll need. Chances are most of the hoses are going to be the same diameter so you could buy a roll of hose, the ends in bulk, and maybe just one die. Once you're done you could sell the crimper on ebay. That way you would have new hoses without dealing with things like taking oily hoses to your local guy to have them copied.

 

[ctlguy]

My not be the case on this vintage of a machine but later model units (Deere is what I am familier with) there are some hoses that need to be rated at 6,000 psi. This of course is not the gen purpose 1/2 etc hoses but primary pump pressure hoses. Again not necc the case on an older unit but keep that is mind as a gen purpose crimper won't accomplish that, nor will your avg hyd shop build one rated that high unless instructed to do so.

 

[RickB]

Nobody that has responded to this point has raised the issue of pressure ratings for the hoses connecting the hydrostatic pumps and motors. Typical SSL hydrostatic drive pressures can run north of 5000 PSI. Be aware of this, and be certain that any non-OEM hoses you buy or have made will withstand these pressures. Typical 3/4" and 1" hoses made up at a farm equipment dealership, auto parts stores or online discount hydraulic component retailers probably won't meet the required spec without specific request. Hoses for bucket, boom and auxiliary functions don't require these high ratings.

 

[ctlguy]

Actually I did, post was right before yours. I ref 6,000 psi for the units I know.

 

[olde man]

i suggest replacements after 15 years if you feel you want to reuse them and don't want to go to the trouble of building a tester and worrying how much oil to hide from if they burst then get a hand pump with a gauge.Most anyone with a garage has one and they're not that expensive. after all it is a static test and you don't need flow. conserve the oil inside the hoses to save yourself some pumping.

 

[J_J]

Here is a hyd pump with 10,000 psi capability from Grainger.

Air/Manual Hyd Hand Pump, 10, 000PSI - Maintenance Set Ram - Hydraulic System Components - 5M461 : Grainger Industrial Supply

 

[sierradmax]

I appreciate everyones help. I looked at the field connected fittings.. Averaging $50/piece.... That route will get pricey real quick. I took a look at the parts manual last night. I counted 26 hoses under the cab ranging from 3/8" to 3/4". Even if each hoses averages $25/piece, It would be hard to justify buying a hose crimper, fittings and hose to mkae my own. In addition, my original post about testing hoses.... For the quantity of hoses I have, buying a tool to test them (similar to the pump above) isn't worth it.

 

[Discount Hydraulic Hose]

I appreciate everyones help. I looked at the field connected fittings.. Averaging $50/piece....

Where were you looking? We sell field-attachable 1/2" JIC hose fittings for about $14 on our web site. Bulk discounts get you under $12 each if you buy ten or more. SAE 100R2AT Reusable Hose Fittings - SAE 37° (JIC) Female Swivel

$50 a piece is just ridiculous. You shouldn't have to pay that much anywhere.

 

[wdchyd]

This winter I'll be tearing into a Bobcat 763 by doing an engine & hydraulics overhaul. With the cost of hoses, is there a kit that can test hydraulic hoses? i.e., plug one end and an adapter to fit on the opposite end and test with an air compressor?

To be able to test hoses statically you'll need a hyd pump capable of 10,000 psi (as mentioned) .......plug the ends and pump up to "proof pressure" (which is twice the working pressure)......Caution needs to be exercised doing this to old hoses as they can self-destruct because of age/wear/tear......

By the time you go though this procedure you'll find more hoses than you think that you won't trust......rehosing with a reputable hose shop can be more costly than DIY but may be better priced than OEM hoses

While you have the engine and hydrostat out you need to clean up (pressure wash) and inspect all the tubing assembles under the engine.......these buggers are notorious for blown tubing that requires engine removal.........Don't overlook the hydraulic tubing

When undergoing start-up make sure you work clean and keep wheels/tracks off the ground for purging and safety

 

[bigdeano]

I've tested hydraulic components using a grease gun to develop the pressure. Fill whatever you're testing completely full of oil. It only takes a small amount of grease to develop the high pressure. The highest I've gone is 5000 psi because that's how high my gauge went. A good grease fitting acts as a check valve to hold the pressure in case you need multiple pumps.

 

[SPYDERLK]

Here is a hyd pump with 10,000 psi capability from Grainger.

Air/Manual Hyd Hand Pump, 10, 000PSI - Maintenance Set Ram - Hydraulic System Components - 5M461 : Grainger Industrial Supply

Hose ratings are normally 1/4 burst rating. Burst has a time/duration spec associated, but I dont know the duration spec:confused3: . I would expect a 6KPSI hose to withstand 10KPSI for hours, and extrapolating from the 4X convention tolerate impulses to 24K.
larry

 

[wdchyd]

I've tested hydraulic components using a grease gun to develop the pressure. Fill whatever you're testing completely full of oil. It only takes a small amount of grease to develop the high pressure. The highest I've gone is 5000 psi because that's how high my gauge went. A good grease fitting acts as a check valve to hold the pressure in case you need multiple pumps.

Hand or air operated "porta-power" type pumps routinely go up to 10,000psi (enerpac, otc, simplex, blackhawk, power team ect).......

No grease necessary