Howdy,
New to the forum and somewhat new to old tractors, I grew up around some of this stuff, and I work on everything from old motorcycles to old cars, but this is my first antique tractor of my very own.
I picked up a somewhat neglected 641 a few weeks ago. It had sat in a garage for the better part of the last 10 years, ethanol had rotted the carb, but i got the carb rebuilt, ignition system tuned up and it runs pretty good. Someone went through it maybe 30-40 years ago and cobbled together the loader, power steering, and did a bunch of creative but hacky 'upgrades' then since then i think it has been used when it would run and neglected when it wouldn't. Trans, hydraulics were both full of milkshake.
only problem is- when i bought it, there was very little (normal) oil under it from sitting. When i got it started up it blew a gallon or more of oil out of the hydraulic manifold where it bolts to the bottom of the transmission housing.
This was the problem:
I was able to get a pretty good weld on it and it is bolted back on and no leaks. Obviously it was out of tractor juice so i filled it back up with some 'universal hy tran' from Fleet Farm. I shook the 3 buckets and this was the thickest, feels like about 30-40 wt (oil or 80w gear lube). Listed as being for 'ford' but no EP additive so i put 80-90 in the trans and diff.
Anyhow filled it up, no leaks, everything looks good, figured 'here we go' and.... nothing. Not even a hint of raising. So i pulled the plug and bled the system, lots of air coming out, lots of oil flow, but still nothing. There is lots of flow, there is intermittent air coming out, making a sputtery mess. It doesn't look like another youtube video where the guy pulls the plug, waits a few seconts and it runs clear, this thing is just shooting out foamy spluttery oil, but lots of it.
I have to think that even given the miniscule pressure coming out, just by flow alone, i could get some motion on the 3 point cylinder. Even when i lift the arms up the piston wont take up the slack. The first 10 years of my engineering career was spent on hydraulics and this just doesn't look like an air-in-the-system type problem unless there is some kind of piloted valve that wont build pressure to open, and i just don't understand what is happening in the valve/lift mechanism that well yet.
I'm not *scared* per se to pull the 3 point valve/ram cover, its just a good couple hours of work, and i'm not sure if its necessary. I saw the video on youtube with Rachel showing how to bleed with compressed air in the transmission.... that is pretty low impact, once i get my air compressor up and running (just moved 3 weeks ago to the new place) i will certainly try that.
so a few things to ponder:
1) Are these things really that bad to bleed, do i need to get radical and do something like fit a hose from the pump to drain the bleed port into the reservoir and just let it run for a half hour? Its a relatively simple task just takes some doin'.
2) what would have caused it to break the manifold? since it didn't have oil underneath it, it obviously broke on the pressure side and possibly either from freezing water (there was lots of water in the system) or from over pressure (relief valve stuck?) if it broke from water it just so happens to have sat for years not leaking a drop, then when i fired it up, came apart and started gushing? i dunno crazier things have happened but it seems like a long shot
i dunno, where would you folks start looking? do a more thorough system bleed ? Pull the valve body? I read through a bunch of threads on this and i didn't see anyone having this exact issue, is there something dumb that im' overlooking? I'm not opposed to getting greasy but i like to trouble shoot these kind of things in an orderly fashion and would rather not tear up a bunch of stuff for no reason.
New to the forum and somewhat new to old tractors, I grew up around some of this stuff, and I work on everything from old motorcycles to old cars, but this is my first antique tractor of my very own.
I picked up a somewhat neglected 641 a few weeks ago. It had sat in a garage for the better part of the last 10 years, ethanol had rotted the carb, but i got the carb rebuilt, ignition system tuned up and it runs pretty good. Someone went through it maybe 30-40 years ago and cobbled together the loader, power steering, and did a bunch of creative but hacky 'upgrades' then since then i think it has been used when it would run and neglected when it wouldn't. Trans, hydraulics were both full of milkshake.
only problem is- when i bought it, there was very little (normal) oil under it from sitting. When i got it started up it blew a gallon or more of oil out of the hydraulic manifold where it bolts to the bottom of the transmission housing.
This was the problem:
I was able to get a pretty good weld on it and it is bolted back on and no leaks. Obviously it was out of tractor juice so i filled it back up with some 'universal hy tran' from Fleet Farm. I shook the 3 buckets and this was the thickest, feels like about 30-40 wt (oil or 80w gear lube). Listed as being for 'ford' but no EP additive so i put 80-90 in the trans and diff.
Anyhow filled it up, no leaks, everything looks good, figured 'here we go' and.... nothing. Not even a hint of raising. So i pulled the plug and bled the system, lots of air coming out, lots of oil flow, but still nothing. There is lots of flow, there is intermittent air coming out, making a sputtery mess. It doesn't look like another youtube video where the guy pulls the plug, waits a few seconts and it runs clear, this thing is just shooting out foamy spluttery oil, but lots of it.
I have to think that even given the miniscule pressure coming out, just by flow alone, i could get some motion on the 3 point cylinder. Even when i lift the arms up the piston wont take up the slack. The first 10 years of my engineering career was spent on hydraulics and this just doesn't look like an air-in-the-system type problem unless there is some kind of piloted valve that wont build pressure to open, and i just don't understand what is happening in the valve/lift mechanism that well yet.
I'm not *scared* per se to pull the 3 point valve/ram cover, its just a good couple hours of work, and i'm not sure if its necessary. I saw the video on youtube with Rachel showing how to bleed with compressed air in the transmission.... that is pretty low impact, once i get my air compressor up and running (just moved 3 weeks ago to the new place) i will certainly try that.
so a few things to ponder:
1) Are these things really that bad to bleed, do i need to get radical and do something like fit a hose from the pump to drain the bleed port into the reservoir and just let it run for a half hour? Its a relatively simple task just takes some doin'.
2) what would have caused it to break the manifold? since it didn't have oil underneath it, it obviously broke on the pressure side and possibly either from freezing water (there was lots of water in the system) or from over pressure (relief valve stuck?) if it broke from water it just so happens to have sat for years not leaking a drop, then when i fired it up, came apart and started gushing? i dunno crazier things have happened but it seems like a long shot
i dunno, where would you folks start looking? do a more thorough system bleed ? Pull the valve body? I read through a bunch of threads on this and i didn't see anyone having this exact issue, is there something dumb that im' overlooking? I'm not opposed to getting greasy but i like to trouble shoot these kind of things in an orderly fashion and would rather not tear up a bunch of stuff for no reason.