450C hydraulic pump removal

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amos
1010 crawler
1010 crawler
Posts: 360
Joined: Thu Aug 11, 2016 7:29 am
Location: Piney Woods of east Texas

Re: 450C hydraulic pump removal

Post by amos » Tue Dec 19, 2017 9:10 am

Sorry,no easy way but to disconnect each line and blow to clear and check for flow.Assuming you've checked the high pressure relief valve to see if it has failed open or partially open(broken spring will cause this) the first thing I would do is drain hyd tank on right side by operator seat,remove top fill and check return filter that is there. Clean tank while it is open. Then go to front and remove screw on canister filter behind the grill and cut it open and see if there is pieces of rag etc in it.
Could also be something in the 6 way valve manifold so that needs disassembly and inspection as well.
Then also change the drive system hyd filter(not part of main hyd system but might as well check tranny/reverser hyd system as well) that is located on the right side of the machine down low near the top roller and back under the unit(look for a 3 bolt flange).
If you find that something has contaminated the hyd system and that something has disintegrated (blue towel,red rag etc) then all cylinders must be disassembled and cleaned as well.
I think JD calls this a level 3 service and it's a major service cycle usually done after a catastrophic hyd pump failure.
Figure close to 30 manhours on this.
On repair shops: what I don't do myself(I do 90%+ of my own work) I job out to a JD construction equipment dealer shop. The extra $$$ is buying me factory training(hopefully) and most important a warranty on the repair work.I just had to have a 4 cyl JD engine rebuilt on a used piece of equipment I bought sight unseen at auction. During the auction(remote) I asked the seller very specific condition questions. He lied of course and when unit arrived it had 90 wt oil in crankcase(4 quarts high too) and oil in the radiator. I checked all the easy stuff and then, since I was busy putting a dozer back together, sent it to a JD shop for eval. They redid my checks and found nothing and I told them to pull the head. That's where we found a bad previous re-build using junk Chinese parts.Wrong sleeves,scored sleeves,wrong rings,non-seated head gasket,etc. Rebuilt with JD parts by JD techs and I have a zero hour engine and a warranty.
Bill is high (ugh) but 99 times out of a 100 the value is there.
Amos
Pushin hard or diggin deep life is good.
What's ahead is what matters. What's behind is already done.
A fool of a man is he who doesn't ask questions...
God gave us 2 ears and 1 mouth for a reason...

B Town
1010 crawler
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Posts: 314
Joined: Fri Dec 11, 2015 7:04 pm
Location: Western Iowa

Re: 450C hydraulic pump removal

Post by B Town » Tue Dec 19, 2017 7:04 pm

Amos has given great guidance. I think starting with the filter in the tank is a good idea, as suggested before. My 450C loader was acting slow and starved for hydraulic oil. Cleaning the tank and replacing the in-tank filter made all the difference. Take care, Bruce

User avatar
amos
1010 crawler
1010 crawler
Posts: 360
Joined: Thu Aug 11, 2016 7:29 am
Location: Piney Woods of east Texas

Re: 450C hydraulic pump removal

Post by amos » Tue Dec 19, 2017 7:50 pm

Bruce of B Town,
As I mentioned I bring in a lot of equipment to fix,keep or sell and I've found the hydraulic system to be the most neglected system on all of them.Original filters on 25+ year old machines,fluid looking like milk and worse. Hydraulic system is also the most expensive to service(correctly) so the reason is obvious.
Seems simple to me but a $200.00 hydraulic system service that takes an hour sure is easier than the same $200.00 hydraulic system service along with a hyd pump re-build or replacement(8-12 hours and $800.00 to $4200.00).
Thought I saw it all till I saw a used excavator(with dead hydraulics) at auction with diesel in the hyd tank. Someone got confused that day......
Amos
Pushin hard or diggin deep life is good.
What's ahead is what matters. What's behind is already done.
A fool of a man is he who doesn't ask questions...
God gave us 2 ears and 1 mouth for a reason...

jjgurley
40C crawler
40C crawler
Posts: 18
Joined: Wed Nov 15, 2017 12:47 pm

Re: 450C hydraulic pump removal

Post by jjgurley » Mon Dec 25, 2017 7:16 am

I'm unclear on a couple of the details.

1) Is there a filter "in the tank" that isn't described in my manual? I have a spin-on filter on the top of the tank that receives the return oil from the six-way valve. It was my first suspect and has been replaced.

2) Is there an adjustable pressure relief somewhere or are we talking about the one integrated into the six-way valve? Is the latter adjustable or prone to failure?

3) I find the tech manual fairly uninformative, but I think the six-way valve is "open" when "off" and the internal valve is only there to vent when the blade cylinder reaches it's end of travel. Sounds tricky to figure out if it's working with external observations.

I only farmed the work out to a mechanic because I had back surgery and he had an impressive shop. Now that my back is usable, I plan to fix this myself. He's a little evasive when I ask him exactly what he did to what - I think his memory is flaky. His invoice talks about an O-ring kit for the six-way valve, which I don't think exists. He claims the end fell out of the float mechanism and all he did is put it back together (throwing away the four little bits of washer that turn out to be the float jaw device). I'll have to have another word with him.
1981 450C
6405 #355834

B Town
1010 crawler
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Posts: 314
Joined: Fri Dec 11, 2015 7:04 pm
Location: Western Iowa

Re: 450C hydraulic pump removal

Post by B Town » Mon Dec 25, 2017 7:27 am

Wish I could help or see pics on this site. I'm not familiar with the spin on filter you are describing. I 450c I have been around have a rod that pops up out of the tank when restricted. There is a cast top that is bolted to the top of the tank. The filter is under that cast cap, 6-8 bolts. Merry Christmas, Bruce

jjgurley
40C crawler
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Re: 450C hydraulic pump removal

Post by jjgurley » Mon Dec 25, 2017 8:17 am

My manual shows your configuration was on machines up to 354074. Later units had a spin-on filter and a sender for an idiot light. I guess I'll take the six-way relief apart and see if all the parts are there...wish the weather was a little warmer!
1981 450C
6405 #355834

B Town
1010 crawler
1010 crawler
Posts: 314
Joined: Fri Dec 11, 2015 7:04 pm
Location: Western Iowa

Re: 450C hydraulic pump removal

Post by B Town » Tue Dec 26, 2017 9:42 am

Good catch on the serial number break. I don't have any experience with such a "modern" 450C. Hahahaha. Keep us posted, Take care, Bruce

jjgurley
40C crawler
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Posts: 18
Joined: Wed Nov 15, 2017 12:47 pm

Re: 450C hydraulic pump removal

Post by jjgurley » Tue Dec 26, 2017 11:09 am

My factory parts manual has a page dedicated to each serial number generation, so it wasn't much of a catch :)
1981 450C
6405 #355834

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