CA Hydraulic Pump Not Functioning
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=203284
Printed Date: 22 Nov 2024 at 9:46pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: CA Hydraulic Pump Not Functioning
Posted By: dfwallis
Subject: CA Hydraulic Pump Not Functioning
Date Posted: 19 Sep 2024 at 12:44pm
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Not even a hint of pumping, full fresh oil. Do I need to prime it? Not been operated in at least 30 years, probably 40. Piston noise sounds normalish if not a little louder than I remember. Things to check before I take it apart? I adjusted screws out against stops, disabled drawbar control by loosening adj screw and screwing lock screw into the housing, hold plate locked together. I'm betting suction ball bearing stuck, rusted... ------------- 1952 CA13092 |
Replies:
Posted By: dfwallis
Date Posted: 19 Sep 2024 at 1:58pm
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Ok, oil drained, delicate workbench cleaned, let the surgery begin:( I was hoping against hope, but not unexpected. ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 19 Sep 2024 at 2:50pm
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Stuck piston, gobs o gunk in intake...suspiciously, one of the mounting bolts was loose. ------------- 1952 CA13092 |
Posted By: steve(ill)
Date Posted: 19 Sep 2024 at 3:56pm
  ------------- Like them all, but love the "B"s. |
Posted By: dfwallis
Date Posted: 19 Sep 2024 at 4:18pm
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How do you unstick a fully depressed piston, nothing to grab onto, no back side access. ------------- 1952 CA13092 |
Posted By: steve(ill)
Date Posted: 19 Sep 2024 at 4:30pm
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is there a port 90 degrees to the side to blow air into the top of the piston ? If air is not enough, maybe soak thru the port with penetrating oil, then put a spoon full of oil thru the port and compress to build up psi ? ------------- Like them all, but love the "B"s. |
Posted By: dfwallis
Date Posted: 19 Sep 2024 at 4:44pm
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Check valve port inline, but none of the balls move. I haven't researched which direction they check ------------- 1952 CA13092 |
Posted By: ekjdm14
Date Posted: 19 Sep 2024 at 5:12pm
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Assuming it's stuck because of gunk and not mechanical damage, I'd be inclined to throw it in either a heated parts washer* or ultrasonic tank to try and free things up. If it doesn't loosen the piston it at least ought to free up the check balls and allow you to use air. I mention damage because of the loose bolt, hopeful someone didn't gouge it up trying to remove previously. *A dishwasher, minus the salts, can suffice in a pinch. Just make sure to oil parts after drying to avoid flash corrosion, and DO NOT attempt if there's a chance of being busted in the act by the wife! Ours takes about 50 minutes including drying cycle.
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Posted By: dfwallis
Date Posted: 19 Sep 2024 at 6:26pm
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Dad suggested tack weld to it ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 19 Sep 2024 at 6:35pm
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Omg, I kept tapping on it a little here and there now and then, and it popped up!!!!!! It appears to be just a very tiny amount of rust on the cylinder and piston. Not bad at all, the spring is like new also. Surprising that it was stuck that hard. When it popped, it almost came completely out of the cylinder. ------------- 1952 CA13092 |
Posted By: CA13414
Date Posted: 19 Sep 2024 at 9:13pm
Wow, that is awesome! Agree and makes me think about being more careful with keeping the oil clean!!! ------------- Helping the aged survive and thrive! 1953 CA |
dfwallis wrote:Posted By: dfwallis
Date Posted: 20 Sep 2024 at 9:47am
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Some of what looked like rust is actually varnish/shellac. Comes off with goof off. Check balls removed by adding 80wt to the cylinder and tapping the piston a few times. All but one rusted/pitted on one side. Will replace all. ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 20 Sep 2024 at 6:39pm
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I've finished reconditioning the pump and hold valve. All new check balls installed...the seats look to be in good condition. Tomorrow drawbar control and reassemble...fingers crossed...bad thing about being super rural is that both small town hardware stores don't stock ball bearings (balls)...ended up driving about 35 miles just for some silly 5/16 ball bearings. ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 21 Sep 2024 at 10:27am
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The drawbar linkage plunger appears to have one complete spring and about 3/4 of a second spring intertwined...obviously that was intentional...what effect were they trying to achieve? Looks mostly pristine other than the plunger rod L shaped head pretty rusty...treating with rust reformer and ceramic paint. ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 21 Sep 2024 at 1:18pm
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Whatever it's intention, the intertwined springs cause plunger fit and movement issues and risks scoring the cylinder wall so I'm returning to a single spring...now where'd that rectangular retaining clip fly off to ... ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 21 Sep 2024 at 4:35pm
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Attempted pump prime procedure. It seemed to be working. Kind of hard to pour into the inlet while manipulating the plungers but seem to be pumping. Reassembled and mounted the pump. Linkage, hoses, and refill oil next, then...dun dun dun dun..the moment of truth... ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 21 Sep 2024 at 5:42pm
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Bad news...still not even a hint of attempting to pump. It is much quieter than before...good or bad idk ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 22 Sep 2024 at 11:58am
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It appears that the (over) loading valve bearing ball is completely missing...could that cause the no hint of operation symptom? Its always returning to sump? What is the correct ball size? It looks to be about 1/8. ------------- 1952 CA13092 |
Posted By: SteveM C/IL
Date Posted: 22 Sep 2024 at 12:10pm
| The ball In the unloader has to be there. It is a one way check. Don't know size. |
Posted By: dfwallis
Date Posted: 22 Sep 2024 at 12:33pm
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I found a 7/32 in grandpa's tool chest that's a close fit, but can't see well enough to be sure :( ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 22 Sep 2024 at 1:50pm
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This post seems to say that the ball is indeed 7/32... https://www.allischalmers.com/forum/ac-vs-modern-hydraulics_topic46904.html" rel="nofollow - https://www.allischalmers.com/forum/ac-vs-modern-hydraulics_topic46904.html This seems reasonable as it brings the plunger wear pattern in line with the fully depressed position...could also be the reason grandpa had a stash of 7/32 balls. ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 22 Sep 2024 at 6:39pm
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I damaged the larger drawbar/lift control housing gasket. The original (homemade possibly) gasket was .01" thick. The thinnest material I have is .03" I hope that thickness isn't critical. ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 23 Sep 2024 at 12:52pm
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Fully disassembled and checked reassembled with unloading valve check ball installed...still not even a hint of function...attempted to prime before install, but there's no inlet check ball, so leaks back out during install...just about at wits end :( I must be missing something... ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 23 Sep 2024 at 1:25pm
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I've found one pic online the shows a check ball in the inlet of the pump...this one has no check ball there...should it? ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 24 Sep 2024 at 12:00pm
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After 4 attempts, left it at former agco dealer...he suggested pto gasket causing a dam, but verified not...oil reaches the lower inlet hole and pours out the upper hole before even registers on the dipstick. ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 27 Sep 2024 at 7:29pm
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Former AGCO dealer says his documentation shows there should be a checkvalve in the lower housing input port...of course not available and so far not enough detail to locate or design an alternate...now who removed it and why????? It must be press fit...the hole is a smooth bore. ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 29 Sep 2024 at 7:49pm
I think the dealer is incorrect. AGCO says the checkvalve on the inlet was added from CA17441 and up. Mine is CA13092 and so probably did not have it. However, CA17441 is actually in the same year (1952). There must have been some issue that caused them to add it. But even so, I don't recall there ever being a priming issue before.
------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 30 Sep 2024 at 7:18pm
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I don't believe it should be necessary, but I've explored some options to make a suitable check valve out of commodity fittings. There are also some serrated press fit ball plunger type housings that might be suitable for conversion but they all seem to massively block flow (like that in the pic above would seem to). It seems like it might be better to increase the inlet hole size to 5/8" and design around that increased inlet size to maintain adequate flow through the check valve. It would help if I knew details of the back pressure. I don't think there is very much based upon my plugging the hole with my thumb trying to judge whether it was pumping or not. ------------- 1952 CA13092 |
Posted By: dfwallis
Date Posted: 02 Oct 2024 at 5:48pm
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Hopefully not needed, but I've created a small press fit check valve that I can use for testing purposes if the repair shop does not find an issue with the pump. I do know that the control valve spring needs replacing, he's doing that. Otherwise, the pump looks like new internally as far as I could see. This will probably need additional minor machining. I left it slightly oversized because I don't have the exact hole size. I measured it with a caliper but just in case, I'll finish it up there. Of course I don't know the correct ball size, "cracking pressure", whether the mod increased the inlet size, etc. This will use an 11/32" ball (not the plastic one in the pic) which is about the largest I could conveniently fit in the housing and allow adequate flow. There is a body depression near the top that I might use for a seal if needed. I'll also probably need a cage to capture the spring and ball. 
------------- 1952 CA13092 |