Allis Chalmers B Hydraulic Questions

pumpkin man wrote:  in your last pict. it shows a return hose hook to the filler hole  what type hdly. cly is on that tractor could be your prob. show more pict. of the pump & cly. hook up looks like a to way cly. on a one way stym.

Here are the pics.  Let me know if they show what you need.

It is a 2-way cylinder but is hooked up correct as a 1-way with the other line just vented.Not been around a B but the pumps are similar in principle to a WD45.There has to be a hold valve somewhere and it sounds like it isn't releasing.On a 45 when the shaft rotates it pushes the ball off the seat to release return oil.Does the thumbscrew bottomed out on the spring have anything to do with that?

yochujr wrote: Steve M C/IL wrote: It is a 2-way cylinder but is hooked up correct as a 1-way with the other line just vented.Not been around a B but the pumps are similar in principle to a WD45.There has to be a hold valve somewhere and it sounds like it isn't releasing.On a 45 when the shaft rotates it pushes the ball off the seat to release return oil.Does the thumbscrew bottomed out on the spring have anything to do with that? If we're talking about the same screw, the manual I picked up says that controls the rate of flow.  I take that as how fast it allows the 4-point to drop.

Correction, I meant to say 3-point.  It's been a long day....

Steve M C/IL wrote: I hear ya. Go to  www.agcopartsbooks.com and use the guest user-view books.In the first box type "b" in the second select agco-allis them submit.A bunch of stuff will come up and click on The B/IB/power unit line.When that page comes up you can scroll down to the hydraulics section and look at those.I looked at the fist one and it showed the pump and pieces.You can clik pic and enlarge  till you get it big enough to see.You have to do some "draggin" to keep it on the page.I usually just click the print button instead and enlarge that but you still can't read the no's on that one.Looks to me like the smaller hex plug they are calling the relief and I can't tell what I'm seeing in the picture but on a 45 that shaft has a flat spot that when rotated,pushes the relief open and lets the cyl colapse.Might try loosening/removing that plug to see if something is stuck.I wouldn't have weight hanging on system to try that.Block it up or something.any way,hope this helps.

This looks like it will be a tremendous help.  I was able to view the parts and locate a dealer within an hour so I should be able to call them Monday to see what they have in stock or can get for me.  Thanks!

try removing that return hose from the filler hole could air locked the cly needs to suck air. you dont need return line you need a vent. thy have vent plugs for useing 2 way clys on 1 way sytms or make your own by cross drilling a pipe plug and putting a cotter key in the hole that keeps the dirt out

pumpkin man wrote: for got to ask what kind of oil is in trans syst. book calls for motor oil [ 20 w -15=40 -10 30 - hy-trans] not 80-90 gear lube its to heavy like tar when cold also back thumb screw out llets valve open more.

I have no idea what's in there right now but I'm sure it needs changed before I do too much.  I cleared out the drain holes (I've heard them called mouse doors) last night and a bunch of water drained out.  The drain holes appeared to have been plugged by a bunch of heavy grease and hair/grass which I assume got in there from a rodent.

As for the return line, you're saying to take the line off the cylinder that's closest to the ram?  Right now, it looks like this goes into the trans just behind where my left foot sits.  If I eliminate that line do I plug the hole it goes to in the trans?

One other thing, I got the I&T manual but it doesn't seem to show any sections on draining all the fluids and filling it, only capacities.  Do the entire hydraulics and trans all run off the same fluid?  I'm sure I'm showing my ignorance but I think I'm starting to pick it up a little.  Thanks again for the helpful posts.  It's nice to know this is one of the few good forums where people are actually willing to help!

Steve M C/IL wrote: That would be a good idea to try first.When lift is raised and won't go down,just loosen the connection on the line and see if it bleeds off and lets arms crawl down.Then you would know there is no problem with the line or cylinder.As stated,they make "vents" for 2-way cylinders which would be more desirable than the extra hose.Any place that sells cylinders should have them and then just plug the other end/hole that now goes in by your left foot.

Interesting, so the vent with only allow air out and no fluid?  I will definitely try to loosen that hose.  There shouldn't be any real pressure on it, right?  Also, when I loosen it slightly and if that's the problem they should bleed down but also still raise if I'm understanding correctly?

Steve M C/IL wrote: Yeah,I'm just saying to crack and loosen the hose that feeds the cyl to see if by letting the oil escape there it will let the cylinder colapse.If the oil bleeds out but the cyl won't compress you got something wrong with the hose or cylinder.If that's the case then remove the hose first to see it blows free then try to compress the cyl.Cyl should be able to compress with no hose by just pushing down on lift arm.

I do know that something is bleeding off as it is because as long as the pto is not engaged, the hydraulics will bleed down with or without a load on it.  After I shut the tractor of after the 3-point is raised, I can push on the drawbar and hear a leak somewhere and I suspect it's in the cylinder.  If that's the case, I can live with that for now as long it will will hold up but I have no way of lowering with the pto engaged.

I will bet money if you remove the hose that goes back to the tranny fill hole, you will have a mess of oil all over after raising the 3PT. That 2 way cylinder has a leak-by in the piston or the original owner wouldn't have gone to the trouble to run a return line. That side of the cylinder shouldn't have any oil in it unless the piston is leaking. I would also bet the reason the 3 pt goes down after shutting of the PTO is because the oil is leaking past the cylinder piston and following the hose back to the fill hole.
 With the "return" line disconnected and anchored into a bucket, raise the blade up and shut the PTO off. Watch the oil leak out of the hose, into the bucket.
 That still doesn't fix your original problem of letting the 3 Pt go back down. I would leave the return hose in place if the cylinder is leaking by and concentrate on the valve operation until you have more time to mess with it.

were the return hose is hooked to the trans s the fill hole takes a 1 inch pipe plug  you do not need a return line if that cly. has oil in that side [where the return line hooks on]then the cly. is leeking [its junk]cost more to fixthan its worth. ther are 3 dra in plugs on the bottom of tras-rear end-& P T O houseings should have a 3/8 square hole in them take them out one at a time drain each unit refill with fuel oil [with the scraper off the tractor] & P T O off drive it around the yard for a wile then take the pump hose off the cly. put it in a pail  put P T O in gear and work the pump this should flush the pump drain the fuel oil out of the houseings  this will flush the crap out  then refill with oil[motor-oil] [not 80-90 gear lube]  put a ad in the forum want ads for B or C hdl cly.

yochujr,  That cylinder is at least 50% bigger then the original one and It sounds like oil is leaking past the cylinder, as has been suggested.  The older AC's ran higher hydraulic pressure then other tractors of the time, that is why they could get by with such small cylinders.  I suspect something is stuck in the pump/valve and all the constant pressure on the inside of the cylinder caused it to blow out the o ring/seal in it.  There are a lot of AC's that used the same system so a cylinder should not be hard to find at a reasonable price.  Good luck.

Here are some pics ov how the cylinder and the 3-point are set up.  Is it still possible to directly replace this cylinder with an original one or will it require some kind of fabrication?  There seems to be so many out there, I have not been able to find any pics or info on exactly what my setup is supposed to look like.

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"If I'm not going to mess everything up, I would eventually like to find an original cylinder put back on there but it's got me questioning now whether that 3-point was even original to the tractor."
The B Allis Chalmers never had a 3point hitch. All were add ons.
"were the return hose is hooked to the trans s the fill hole takes a 1 inch pipe plug  you do not need a return line if that cly. has oil in that side [where the return line hooks on]then the cly. is leeking [its junk]cost more to fixthan its worth."
 In 15 years of machine repair work I don't believe I ever scrapped out a hydraulic cylinder. I have made new rods, replaced packing, manufactured and replaced packing glands and even made new jugs for cylinders. If there was a direct replacement available for the application a new cylinder might have been used once or twice. Charlie

your not listing to what we have told you to do. spend $6 dollors for some fuel oil - drain  the sys. flush it .put new oil in check the cly for leeking then you wiil have some idea  of whats wrong. if it was mine I would get rid of that cly. & find an orgl. you can get one for less than $50 put a want add in the Forums want adds. the pump is working if its lifting up but not going down [right] the return valve is pluged or dirty. thats what the flushing mite take care of if it dosent then tair in to the pump.

I knew I got the oil reccomendation from somewhere.  I read back where you was 20w-15 motor oil