450C loader cycles slow and will not lift loaded bucket

ridgerambler · Post by **ridgerambler** » Mon Jun 27, 2011 1:17 pm

I have 76 450C loader with 4 in 1 bucket-no rippers- and the loader hydraulics function cycles slow and it will not lift with load in bucket. It does not matter if at idle or high rpm...I suspect pump is either worn or splines on shaft are worn, but don't know for sure because it could be loader control valve or relief valve. I don't have gauges to test hydraulic system, but pump is $1600 from JD and don't want to just start swapping parts until I get the right one. Any suggestions on how to narrow it down. Crawler pulls, turns, etc fine. Fluid is at level and filters are ok...

JWB Contracting · Post by **JWB Contracting** » Mon Jun 27, 2011 1:45 pm

1. Make sure that your hydraulic fluid is toped up to proper levels.
2. Check your filters, 450's are mounted in the tank.
3. Relief Valve, can you here it kicking out when you activate the loader hydraulic valve.
4. Check the main feed / supply line to your pump, it might be colapsed. Factory was mostly steel but you do see some replaced with rubber hose.
5. Install a hose on the output side of the pump into a pail and see if it is pumping.
6. Crack / loosen the pressure line to your valve and see if you have fluid coming.

If you have fluid to the valve and your relief is not engaging then the problem would have to be in the valve and the cylinders. Not likely the cylinders as they would not all go at once.

Number 5 and 6 are not the safe way of checking, but do not require a guage or any other special equipment. If you have any hydraulic function it should not be the pump drive, they either work or they are stripped.

ridgerambler · Post by **ridgerambler** » Mon Jun 27, 2011 5:09 pm

Thanks Jason, I will check those tips you posted, I hear nothing from the relief valve when loader control valve is activiated. Should it be clicking or make a audibile noise? Mine does have rubber hose and I thought about collapsed line, but have not had chance to check out yet. I did check and steel line is still available from JD. Just finished steam cleaning today so I can see what's going on and have removed front nose and radiator (it needed work anyway), so all is in clear to check on pump. After had time to check it out more, may come back with more questions/comments. Thanks again for information.
Tom

KenP · Post by **KenP** » Mon Jun 27, 2011 5:18 pm

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ridgerambler · Post by **ridgerambler** » Mon Jun 27, 2011 6:12 pm

I would love to follow that route, but only thing I have found so far is OTC 4235/4221 and they are $2500-$3500 range, and 450C is only crawler we have at present. JD will send a tech to our site for $150/hr plus mileage with a minimum of 4 hours for testing only. This is a farm machine not used off site, so no truck/trailer large enough to haul it to dealer. If I had multiple machines, I would invest in hydraulic system tester up front in a heartbeat. We have several ag tractors and do all our own repair, and if could find good hydraulic test equipment at lower cost would invest in that route. That may be way we end up going because there are some plans to add a dozer in a year (or so), but for right now with economy here still sorta ...well...not that good, my Scottish ancestery is showing...

CatD8RII · Post by **CatD8RII** » Mon Jun 27, 2011 6:12 pm

A good gauge with adapters cant be more than a few hundred dollars. And its not like you cant use it on other machines. When cracking lines loose you have to be extremely careful. Fluid injection injuries are nothing to mess around with.

CatD8RII · Post by **CatD8RII** » Mon Jun 27, 2011 6:40 pm

You dont actually need a "tester". A tester usually means a flowmeter, whch is high dollar and kind of over the top. All you need is a gauge, a hose attached to the gauge, and adapters to connect the hose to the control valve. A decent hydraulic hose shop should carry the stuff you need.

Tigerhaze · Post by **Tigerhaze** » Tue Jun 28, 2011 11:31 am

Hi- can you post a manufacturer/model or link to a gauge you would recommend? I have been thinking about this for my H-L-R but am not experienced with diagnosing hydraulic systems.

Willyr · Post by **Willyr** » Tue Jun 28, 2011 12:11 pm

NH Northern has a guage for $20.

http://www.northerntool.com/shop/tools/ ... _200322889

Go to a hydraulic store (most auto parts can help) adapt the guage to a fitting on the end of your system. Should not be more than $50 in all.

CatD8RII · Post by **CatD8RII** » Tue Jun 28, 2011 12:33 pm

Tiger

There are two ways to go

The first way would be to get a gauge that does a specific range of pressure.
Im not sure what your HLR pressure runs at but whatever it is, you should try to get a gauge that reads that pressure near the middle of its range. Say your pressure is 200PSI, you should get a 500PSI gauge. This is the cheapest way to go, but that gauge can only be used for that specific range of pressure readings. I really like Parker prouducts but their website is overwhelming at times, I also like Wika gauges too, you can see a selection of them here.
http://www1.mscdirect.com/eCommerce/Nav ... ure+Gauges

The other way to go would be to get a digital gauge. These have transducers that convert the pressure to a voltage that the "meter" reads. These are nice because they can be used on any pressure, the only downside is they're allot more expensive.

You can see Parkers stuff here
http://www.parker.com/portal/site/PARKE ... tky=GAUGES

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450C loader cycles slow and will not lift loaded bucket

450C loader cycles slow and will not lift loaded bucket

Here is what i would do and in order.

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