450c 6-way fittings?

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jjgurley
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450c 6-way fittings?

Post by jjgurley » Tue Nov 19, 2019 10:52 am

My JD450 has "slow" hydraulics, and I'd like to figure out if it's the pump or the relief valve inside the 6-way. I figure the best way to isolate the problem is to put a Tee, gauge, and valve (on the downstream side of the tee) on the inlet to the valve and see how the pressure responds to the valve constricting flow. The problem occurred suddenly when I had some service done, and the mechanic claims the 6-way "just fell apart" on him, so I'm thinking that's the problem. I've since decided the mechanic is pretty unskilled. My inlet to the 6-way is 5/8" OD tubing, and the male nut is 1 1/8" and the female side is 1 1/4". Is this a -10 JIC or something else?

Open to better diagnostic ideas!

gaspumpsam
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Re: 450c 6-way fittings?

Post by gaspumpsam » Tue Nov 19, 2019 11:08 am

If you had good hyds before- then someone played with this 6 way, now you have slow hyds, I would remove 6 way, have it repaired/ replaced properly, then try hyds, more than likely you will have good hyds again.

jjgurley
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Re: 450c 6-way fittings?

Post by jjgurley » Tue Nov 19, 2019 11:27 am

It's not quite that simple. The mechanic replaced the steering clutches, the brake bands, one of the drums, and replaced the pins and bushings on the 6-way, so the hydraulics were open for a few weeks. The tipoff that he wasn't literate enough to read a manual is that the float valve "somehow" came apart, and he found a "shattered washer" which he threw away. That was the float mechanism, so of course float quit working, which I've since fixed. He bought a o-ring "kit" for the six-way, and it includes the pressure relief, so I'm pretty sure he opened that up. But a squirrel could have dropped an acorn in a supply line or something, as well.

I agree I should just pull the 6-way or at least open up the relief, if I can get to it, and count the parts. Unfortunately, the manual is pretty vague about the valve. Last time I took the 6-way out, I drooled hydraulic everywhere and made quite the mess.
1981 450C
6405 #355834

Jim B
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Re: 450c 6-way fittings?

Post by Jim B » Tue Nov 19, 2019 12:26 pm

Speed is flow, the better the flow the greater the speed of a function. Restricting the flow and watching the pressure is not the way to check flow in my opinion. The right way to check the pump condition is with a flowmeter. In the Hydraulic System Operational Checks section of your technical manual it should describe how to check cycle times (minimum and maximum) of a function. That will give you an idea of pump condition. If the cycle times are too slow then a flowmeter is called for to continue diagnosis. Make sure the valve control handle is adjusted to move spools full stroke and equally in both directions. If the control handle linkage has too much wear it may not fully open the spools.

While your complaint is speed (flow); have you done a pressure check since the valve was torn apart? The relief valve may be out of adjustment if it was taken apart and has not been checked/adjusted.

It appears you have been chasing this for a couple years now, from looking a your past posts. It may be worth it to get an estimate from your JD dealer, or a shop with the test equipment, to do a true hydraulic diagnostic, including flow check of the pump. Having a proper evaluation done may be more cost effective than the other option, which is to start tearing apart and replacing things in hope of finding the problem. Not trying to give you a hard time or question your skills, but sometimes tools and equipment, we don't have, are needed to do a job right. Just my opinion for what its worth.

jjgurley
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Re: 450c 6-way fittings?

Post by jjgurley » Tue Nov 19, 2019 12:38 pm

I live in the boondocks, and a real JD dealership is 200 miles away. It would cost a couple hundred just to get it there. For my use, the slow hydraulics are more of an inconvenience. To my engineering mind, flow and pressure are pretty tightly connected. If my pressure relief is leaking or maladjusted, it would affect both, at least to the cylinders. If my guess that it's the relief valve is correct, the pump flow test would look fine.

Now that fire season is over, maybe I'll have time to dig into it before it gets too cold and wet.
1981 450C
6405 #355834

jjgurley
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Re: 450c 6-way fittings?

Post by jjgurley » Tue Nov 19, 2019 1:15 pm

I re-read the parts and service manual, and they refer to the pressure relief as "adjustable". Anyone know how it's adjusted?
1981 450C
6405 #355834

Jim B
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Re: 450c 6-way fittings?

Post by Jim B » Tue Nov 19, 2019 1:23 pm

I don't have a 450C manual so can't tell you a page. I'm going to the parts catalog to check but I believe there are shims under the cap to adjust the pressure. Your manual should point out the recommended location to tap in your gauge. Back to you in a bit.

Jim B
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Re: 450c 6-way fittings?

Post by Jim B » Tue Nov 19, 2019 1:48 pm

From looking at the parts catalog and comparing the relief valves of the 450B, 450C, and 450E, it appears the relief valves on the 450C and 450E, with the 6405 blade, is not adjustable. Parts are available to reseal it if it is removed from the valve body, but it has no field adjustment with shims or a screw, as was common in some valves. This is similar to the relief valve info I find for my 450E, with a 6405 blade, in the parts catalog. The technical manual says " If pressure is not to specification on dozers, remove and inspect relief valve for damage and debris. Replace relief valve." The loaders used a different valve and relief as they tell how to turn the adjusting screw for those.

Is your manual John Deere's TM1102?

jjgurley
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Re: 450c 6-way fittings?

Post by jjgurley » Tue Nov 19, 2019 2:00 pm

The valve inlet has a 90deg elbow with a 3/8" drain plug in it, so I just ordered a short hose and gauge from SurplusCenter. My parts manual lists a shim and the quantity is "AR" so probably "as required". Thanks.
1981 450C
6405 #355834

Jim B
350 crawler
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Posts: 2080
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Re: 450c 6-way fittings?

Post by Jim B » Tue Nov 19, 2019 2:02 pm

If your serial number is 355834, that is prior to S/N 380196 and is adjustable by shims 17 and 18 in this drawing. 380196 and after are not field adjustable, my error.

https://partscatalog.deere.com/jdrc/sid ... gId/259914

Yes shims as required.

gaspumpsam
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Re: 450c 6-way fittings?

Post by gaspumpsam » Tue Nov 19, 2019 3:09 pm

jjgurley- your engenering mind is absolutely correct! Flow and pressure go hand in hand.
The way to flow/ pressure test any hyd pump is to put flow meter directly into outlet of pump, so any oil from pump has to go thru flow meter. Then put RPM of pump at a predetermined test amount, ( some is 1000 rpm) then put approx 100 psi restriction, then see what GPM is(warm oil) then increase pressure in (usually 500 psi increments) and record all readings.
Compare to specs, you will very soon see if pump is ok, or at what pressure it shows it cannot produce proper flow.

jjgurley
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Re: 450c 6-way fittings?

Post by jjgurley » Tue Nov 19, 2019 3:14 pm

Flow meters with valves and pressure gauges are a pretty pricey tool. At 69 yrs old, I really should be shrinking my toolbox, not expanding it, although my wife considers it good second husband bait.
1981 450C
6405 #355834

gaspumpsam
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Re: 450c 6-way fittings?

Post by gaspumpsam » Tue Nov 19, 2019 3:42 pm

Yes they are!! (Expensive- not second husband bait!!!)
If you can tap into pump to valve inlet line and put a good pressure gauge in, with a hose so you can read gauge when you activate hyds, then bottom or move to extreme the bucket tilt back( usually safest) read gauge, I think should be around 2200 psi, but check specs to be sure, then add shims(measure how thick of shims you use,) then see what new pressure reading is.
Then you will know that amount of shims raised pressure the difference from first reading to second reading, then if you are still low, you will be able to come pretty close to amount Of shims you will need to get pressure proper.
But- ( there is always a but) if you shim relief valve and it doesn’t raise pressure, be very careful of adding more shims.
problem could be somewhere else!
69 isn’t old- just quite a bit of expierence !!

jjgurley
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Re: 450c 6-way fittings?

Post by jjgurley » Tue Nov 19, 2019 3:54 pm

I'm thinking additional shims would lower the relief pressure, right? Seems like it's pretty much like a fuel injector, compressing a spring.

There's an additional problem of access to the relief valve. If I take off the T-handle linkages, I can probably get to it. There is a access slot on the front of the housing, but it's pretty small. And my hands are pretty big...
1981 450C
6405 #355834

Jim B
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Re: 450c 6-way fittings?

Post by Jim B » Tue Nov 19, 2019 5:10 pm

Adding shims usually increases pressure as each shim added compresses the spring slightly, so it takes more pressure to lift it off its seat.

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