[How-To] Hydraulic plumbing: how do I stop this from leaking?

So, small victories this morning...

I found (on this site no less!) a US Army manual that is more similar to my machine. In it, I found 3 important pieces of information:

1- Where to hook up a pressure gauge. I don't have the part they plug into, but it shows to do it right next to the pump, where i DO have a plug I could install it. This is where I was going to put it anyway actually!

2- Where the pressure adjustment valve is. It is actually pretty clearly a part that the 'refurbisher' I bought from cleaned/replaced/took apart. I'm guessing at least 1/2 my problem is this adjustment.

3- Most importantly, when and how to bleed the system! Turns out, my symptom is EXACTLY the situation where the system needs bleeding. I think when I pulled the speed control valve apart that I drained enough fluid/introduced air into the system. I got side-tracked by some thermal event in the motor/motor control that lead me down the wrong path.

SO, turns out I wasted my time trying to track down a couple of minor leaks. I think i caused the cross threading above when trying to re-assemble, so I'm going to have that line (plus 1 other that makes reassembly easier) remade in rubber today at NAPA. I have a set of NPT taps coming in tomorrow that should let me clean up the threads on a bunch of parts, so I can reseal and re-assemble everything early in the week!

This time, I'm going to let the sealant cure (I picked up the loctite 567, also coming tomorrow, as suggested above!) before starting the system, then bleeding the system for a while. The procedure is to just let it run un-molested for a few minutes until it purges the air out!

After that, I'll install my pressure gauge, block the travel of the head, and get my pressure built up to spec!

TLDR; I found a manual that showed me I'm an idiot for chasing the small leaks, broke stuff in the process, and caused the problem by letting air into my system.

EDIT: ALSO showed me which thing is the filter! I can pull it easily enough and see what it takes to replace THAT!
 
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SO, further update for those who care.

On Saturday I went to try to get hoses made. 1 of the two works fine, but the other ends up being too short to accomplish what I wanted. SO, I decided to change my design and get a 90-degree 1/2NPT 'swivel' Male to Female (where the MALE is the swivel side). Unfortunately, NAPA and everyone else didn't have this part. I had to order it online and hopefully it'll show up later this week.

I spent Sunday (it was great out!) starting to clean up and re-assemble what I could. I pulled apart a number of joints, cleaned them, and resealed them. I also cleaned up a bunch of 50 year old goop off of surfaces as I could.

There were 2 things that basically made me cry though...

1- While I was cleaning a spring for a ball-detent for one of the knobs, it spronged. In my shop, in my gravel driveway.... who knows? To McMaster I go.

2- I was cleaning inside the machine now that everything is out of the way, and discovered something interesting. RIGHT above the 90 degree pipe (hidden from view until you disassemble this far...) is a drain from the ways. Basically, this machine pumps oil onto the ways... and there is a controlled drip RIGHT over where I thought the leak was. I'm about 95% convinced now that not only was it not necessary to fix a leak this size ANYWAY, that it never was leaking.... I was misinterpreting a drip pooling around this connector as this connector leaking.
 
Sorry, see it so often......especially with very old equipment.
Manuals are your friends........
"Complete Disassembly and cleaning can lead to understanding"
 
FWIW, the manuals on these are INCREDIBLY undetailed. There are about a dozen different adjustment screws along the way that I've found with no mention as to what they do in the manuals whatsoever. Also, neither manual matches my machine right anyway. So the 'complete disassembly' seems to be my only real way to understand :)
 
ErichKeane said:
FWIW, the manuals on these are INCREDIBLY undetailed. There are about a dozen different adjustment screws along the way that I've found with no mention as to what they do in the manuals whatsoever. Also, neither manual matches my machine right anyway. So the 'complete disassembly' seems to be my only real way to understand :)
Click to expand...
Yes. A complete tear down and wash everything, stone it debur it and study it, this is the best way to understand your machine and be able to troubleshoot and repair it.
 
Welp, got it back together and no obvious huge leaks! I ran the system for a while, and it still seems to have air in it, but hopefully it'll get better as I run it more.

There was 1 huge leak when I first got it together, a 9/16" allen drive plug on the inside top behind the speed sensor. I had decided to leave it alone in my re-seal, figuring i shouldn't bother with it: what a mistake that was! I had just enough room reaching in to turn it 1/6th of a turn between two positions, so it took forever to loosen and tighten (with some loctited 567), but after reassembly seems fine.

I ALSO discovered that what I thought was head-oiler is likely the tool lifter. I found this out since it pumps oil only when on the return stroke, and is enough to disconnect the hose :D. I gotta find a better setup on it. Fortunately there is an on/off knob, so it can stay off for now.

I started with a random tool from my toolbox in a tool holder. Not a great grind for a shaper, but the best looking one I had in 5/8". First pass was about 40 thou stepover, 2nd was 8 (which I didn't finish!).

You can see the difference in the finish in this picture, it ended up being very smooth!

PXL_20210309_225511799.jpg

Here's some videos as I did some cuts:
photos.app.goo.gl

5 new items by Erich Keane

photos.app.goo.gl photos.app.goo.gl
 
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