Adding a spool valve

[DavidBarkey]

@thebuildist Bob , take it apart . They are simple , Cap at each end with o rings, springs , washers and a spool . Besides the chance of getting a piece of metal damaging the hydraulics it is a good chance to make sure the ends are clean . I have read stories of people having problems with the spool sticking because of sediment collecting in the end caps .

Dave

[thebuildist]

Just what I needed to hear! Thanks for your input.

If it were you, how would you clean it out to be sure that it's grit free? I'm thinking I should wash the whole thing in solvent before I begin machining, to try to minimize the stickiness of the interior surfaces to begin with. And then blast it with compressed air after machining. And then swish it in the same solvent I used before machining. And then swish it in clean solvent to finish up.

Obviously a parts washer would be great. But I don't have one of those.

[Gordy]

Bob,
Here is a link from a how it work manual. It has a cut away with the TCV/holding valve, it is not a parts manual but may give you enough detail to see what is in there. Scroll down to the page 28 on the pdf counter.

https://manuals.ccigt.com/ServiceManual ... marked.pdf


Gordy

[DavidBarkey]

Just what I needed to hear! Thanks for your input.

If it were you, how would you clean it out to be sure that it's grit free? I'm thinking I should wash the whole thing in solvent before I begin machining, to try to minimize the stickiness of the interior surfaces to begin with. And then blast it with compressed air after machining. And then swish it in the same solvent I used before machining. And then swish it in clean solvent to finish up.

Obviously a parts washer would be great. But I don't have one of those.

Yes , simple varsol will do just fine .
Dave

[Jancoe]

@thebuildist, if you need anymore measurements of the pb hole, let me know. And jot me down for some pb machine work on my spare tcv too.

Sent from my SM-G975U using Tapatalk

[Eugen]

Lots to learn here for me, keeping an eye on this interesting thread. Before I got the 644 I was entertaining the thought of doing this too, and build a loader on a 400 series.

[thebuildist]

Well, there's no turning back now! I now have the PB port machined into the valve body. I used the dimensions from Jancoe, with a small exception: The Parker O-ring handbook says that for a #16 O-ring, which is what's called for here, the bore should be .738 ID and the gland should be .736 OD.

So that's what I did the inner bore to. It ended up being more like .741, which is frustrating. I marched evenly and consistently up to .728, then added .010, which left me with .741. Sheesh. I think it's because on the final pass I was feeding extra slow, to get a smooth finish. (My machine doesn't have power Z feed) But no big deal. I'll just make the gland .739 OD, and the O-ring will stretch a couple thousandths without a problem.

Next it's time to make the PB sleeve itself. I'll be machining a gland and boring out the SAE endi of this SAE10 X JIC 10 swivel, and then I'll silver solder the gland into that bore, which will effectively make it a single piece.

I'd thought about having the PB sleeve be free-floating between the swivel and the inner bore on the valve body, and just have an o-ring seal at both ends. But with the sleeve ID needing to be .445, having an o-ring seal at the SAE end either leaves the wall of the swivel too thin or leaves the wall of the sleeve too thin.

I also considered press-fitting the two parts together, but I don't think that's a good idea under 2100 psi.

The only hesitation I still have is that I may struggle to keep that gland sleeve perfectly concentric when I solder it in. If it cocks even a few thousandths off center in any direction, then the gland end is going to hit the inner bore when I go to screw it in. I'm thinking I may solder the sleeve gland in place before I machine it. The only challenge then is accurately chucking up the swivel fitting in the lathe such that it's SAE10 threads are on center and true to the lathe's rotational axis. I think that's my best chance of success.

Bob

Photos are of the shop made reamer to create the SAE10 o-ring bevel, the shop-made 7/8-14 tap, and the finished hole in the valve body.

[Gordy]

Building tooling and experience. Might be a nice little side business, let us know when you are ready to go into production


Gordy

[Eugen]

Like watching Star Trek techno babble, I didn't understand much but it sounded fascinating! I like it1

[thebuildist]

I'm at the stage of re-assembling the TCV, and I'm doing it from memory and a few little hints that I scribbled with a sharpie as I was disassembling it.

I think I have everything back in place, and the two pressure relief screws set very close to where they started. But I wanted to print out a parts diagram and confirm that I have put the check balls and springs and washers all back in in the same way and order that they came out.

Is there such a diagram anywhere? I see the cutaway diagram in the "how the hydraulic system works" manual. and I see a couple parts diagram for the older accessory lift (single spool) valves. But I'm not finding an exploded view parts breakdown for a TCV itself.

Am I just missing it, or do we not have one?

Bob