Farm Equipment - Wd45 hydraulic pump problems again

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Wd45 hydraulic pump problems again

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=201670
Printed Date: 23 Sep 2024 at 2:31am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: Wd45 hydraulic pump problems again

Posted By: 55allis
Subject: Wd45 hydraulic pump problems again
Date Posted: 05 Jun 2024 at 9:32pm

Well well well here I am again and starting to need nerve medicine with this pump.
I was out sickle mowing just so happily and got done for the day and was driving it home( a 2 mile drive) and heard a pop and looked back at my pressure gauge I have on the outlet and it was over 5000psi ( that’s as far as the gauge will go) and oil started spraying ( still not sure where it was coming) and the control lever would only kick it down to 2000psi when it was all the way down.
I didn’t have far to go so I drove it right into the shed and shut it down and it wouldn’t set the mower down until I turned screw “D” in than it did…
So now I’m wondering what did it do internally to the pump?
Do I dare pull it apart again?

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1955 AC WD45 diesel with D262 repower, 1949 AC WD45

Replies:

Posted By: 55allis
Date Posted: 05 Jun 2024 at 9:35pm

I forgot to mention that the pump and oil was really hot, where if I put a drip of water it would fry…
I’d estimate around 250/ 300 degrees.

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1955 AC WD45 diesel with D262 repower, 1949 AC WD45

Posted By: DrAllis
Date Posted: 06 Jun 2024 at 6:39am

When any implement gets raised to the desired height, you are to pull down the hand lever mid-way to the HOLD position so the pump isn't pumping continually. Also, screw "A" must be screwed into the divot to keep the Traction Booster system shut OFF, which if not done, may have caused the pump to slowly hammer away to high pressure. If the Traction Booster signal linkage fell off the tractor while screw "A" was loosened, this too would turn on the Traction Booster. Turn screw"D" all the way in and start the tractor (after verifying screw "A" is locked into the divot) and see if the pump is asleep or not by moving the hand lever up/down. If all is good, turn screw "D" all the way out and see what happens. Did you wash out the hydraulic sump really clean while the pump was off the last time ??

Posted By: 55allis
Date Posted: 06 Jun 2024 at 9:06am

I do put the lever to the “hold” position most all the time…
And I have/had everything set to the HOLD as instruct on the battery box…
Not trying to be hard but I’m just saying.
I cleaned the housing with gasoline the first time because it had a slime, but than I flushed with diesel to make sure it was clean.

Thanks Drallis!!!

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1955 AC WD45 diesel with D262 repower, 1949 AC WD45

Posted By: 55allis
Date Posted: 06 Jun 2024 at 9:59am

I just did what you said Drallis and the pump is asleep with screw D in.
It will now top out right at 5000psi but it settles right down to 1500psi unless I hit the clutch and release than it will go right back to 5000psi.
That kinda confuses me but I’m sure something else is wrong that I’m not seeing…

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1955 AC WD45 diesel with D262 repower, 1949 AC WD45

Posted By: Allis dave
Date Posted: 06 Jun 2024 at 10:03am

What was the maximum relief pressure before this problem started?
I don't remember your previous post. Did you have low pressure and add shims to the relief valve when you had it apart?

Posted By: DrAllis
Date Posted: 06 Jun 2024 at 10:34am

The unloader valve seems to be opening at 5K. The pressure will settle down and at some point will re-pressurize again to 5K and over and over again as long as the Lift/Lower lever is up when it should be in HOLD.

Posted By: 55allis
Date Posted: 06 Jun 2024 at 11:04am

Yes Dave I did, it was too low of pressure to pick anything up. I think it was 1200 to 1500psi max before.
So does that mean to pull some shims?

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1955 AC WD45 diesel with D262 repower, 1949 AC WD45

Posted By: SteveM C/IL
Date Posted: 06 Jun 2024 at 12:45pm

After the first rebuild,what was your max pressure? When pump unloads it will quickly drop max psi down to that 1000-1500 number. My question is,how much shimming and what was the result? Do too many?

Posted By: 55allis
Date Posted: 06 Jun 2024 at 1:52pm

When first started working on it I put new O-rings (innocently) and cleaned the traction booster mechanism housing (it was full of sludge) and than later put new balls and springs when it started not lifting my implements so that didn’t help so I added 3 shims and it helped the problem and I think I added 4 more and it fixed the problem until now…
I hope that makes sense…

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1955 AC WD45 diesel with D262 repower, 1949 AC WD45

Posted By: 55allis
Date Posted: 06 Jun 2024 at 2:27pm

I just pulled the pump and counted 10 shims total.
So I’m going to pull 4 shims and that should put it at 3600psi?

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1955 AC WD45 diesel with D262 repower, 1949 AC WD45

Posted By: DrAllis
Date Posted: 06 Jun 2024 at 2:39pm

Too many shims didn't cause the pump to get hot. The pump linkage to the hold valve must be off in adjustment, (maybe only 1/4" of an inch) causing the pump to be turned on while the HOLD detent was engaged. Either that, or you didn't have the lever in the HOLD position. There is a decal under the hyd lever on the quadrant instructing the operator to keep the lever DOWN when not in use. HOLD position is fine. Anything above ( properly adjusted linkage) HOLD turns on the pump and it cannot tolerate constant pumping against the unloader valve.

Posted By: Allis dave
Date Posted: 06 Jun 2024 at 4:04pm

I can't think what it would be, but I wonder as it got got if some dirt came loose or something freed up the unload valve to original working condition. Meaning the extra shims now added too much pressure.

I'm with Doc, figure out what's misadjusted that cause it too run too much and get hot. Remove some shims too becasue for whatever reason, it's unloading too high.

Posted By: 55allis
Date Posted: 06 Jun 2024 at 4:24pm

I got the pump back on after replacing 2 O-rings that I didn’t like and taking 4 shims out..
Now it goes right to 3600/3700psi but will not lower unless I turn screw D in.
It acts like it’s pumping with the lever in any position.

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1955 AC WD45 diesel with D262 repower, 1949 AC WD45

Posted By: Allis dave
Date Posted: 07 Jun 2024 at 7:10am

The operator manual has detailed instructions how to set all the linkages. I would do that to make sure everything is adjusted correctly. That goes back to what Doc said.
For some reason the pump was pumping all the time while in the hold position. Somehting is out of adjustment.

Posted By: 55allis
Date Posted: 07 Jun 2024 at 11:42pm

Hmmm…
I can unhook the lever and run the lever right off the pump and it doesn’t make a difference.
As so as I move the lever and return it, it goes up until I turn screw D in.

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1955 AC WD45 diesel with D262 repower, 1949 AC WD45

Posted By: DrAllis
Date Posted: 08 Jun 2024 at 6:19am

Something inside the pumps control box is turning the pump "ON". Screw D (when screwed inwards) is shutting the pump "OFF". Screw D is intended to be a speed control for the pump but it can completely shut the pump off when screwed fully in.