Hydraulic help - pump cavitation with loader

[cobra2411]

Brazing IMO is a superior repair to soldering but soldering probably would work fine.

I was an HVAC installer for many years and brazed more joints than I care to remember. I do know the type of brazing rod is important as is whether you need flux, types of metals you can join, working temps, etc. Copper to copper with a copper / phosphorous rod you don't need flux. But it work work with steel at all... I haven't brazed steel in over 30 years... HVAC systems used to be soldered but moved to brazing because of higher system temperatures and pressures and the superior strength of the brazed joint.

The two processes are related with soldering occurring below 840f and brazing being above 840f but below the melt point of the parent metal. I disagree that they used silver solder on the original joint because when I got it to temperature to braze the original joint was still solid. I'm thinking maybe nickel - silver? After a little research I went with a silver - copper - zinc rod as it has great mechanical strength and the ability to bond with a number of different metals. I used the matching flux and pulled the lines partially free, but not completely off the tractor and that's my only concern. It was a little difficult to get good access to work the whole joint. I'm used to that with HVAC systems so I'm optimistic, but if there's a defect in a blind spot the only way I'll know is when I use it. If that's the case I'll probably completely remove them for better access.

As far as overheating the metal, etc, I disagree there too. The big "don't" here is quenching the work. You have to let it cool on it's own, which is what I'm doing now. I guess you could overheat the tubes but you would end up having to get them severely over temperature for brazing. The melting point of steel is about 2,500f and the working temperature of the brazing rod I chose is 1,300f. A nickel-silver rod is about 1,700 which is why I suspect it along with the color. But there are and where other types of rods so...

When you braze you want to heat it up till the rod melts when touching the base metal, then you work the torch on and off the work area to keep the braze material in a soft plastic form. Too hot and the braze material will run. So my working temps are around the 1,300 +/- 100f I'd guess. Maybe less. This lets you build up a repair area if you need to. Too hot and it will all fall off and you'll only have a thin coating. Solder responds the same way just at a lower temperature. I actually have problems soldering anymore because I tend to overheat the joint...

Once done, if you quench the tube you'll induce stress and hardness and you can crack it immediately or weaken it enough to cause problems down the road. Heating and air cooling anneal or soften the metal - you don't end up with stress. Properly done the joint should be stronger than the parent metal and last a very long time.

As for cleaning, I sanded, wire brushed and hosed everything down with brake clean, non-chlorinated to be safe. This is one of those "clean it till it's as clean as you can get it then clean it some more..." kind of things. Also, NEVER use chlorinated brake clean around open flames, particularly indoors. An open flame heater in a closed garage in the winter using chlorinated brake clean is a recipe for death... Outside and letting it completely evaporate before adding fire is probably fine but I didn't risk it.

Anyway, I just have to wait for it to cool, clean the flux, reassemble it, fill and test.

Finger's crossed...

[ricky racer]

It sure sounds like you know what you're doing. Good luck!

[cobra2411]

And it's leak free!

Quiet too.

[ricky racer]

Another job well done!!!

[cobra2411]

Now I have to clean up the plumbing at the front and deal with the leaking seals on the curl cylinders... I also have to deal with some of the wallowed out holes on the loader.... Various coolant and oil leaks... Get new tires... Tune up, oil change, etc... All the normal "I just bought a tractor that needs some TCL" kind of stuff...

Obviously I replaced the lift cylinders with some double acting cylinders so I have power down. I also went slightly shorted for price reasons and because this is a lo-boy loader butchered, er, modified to fit a standard tractor so the bucket doesn't go as low. Seems to have worked out great. I got the cylinders at Surplus Center for $80 each in that size only. In other sizes they were more than twice that.

Speaking of the bucket, I picked this 48" bucket up a few years ago on Marketplace for $50. Even then I couldn't have bought the steel to build one for that price. An investor bought a junk house and had no idea what it was to or how long it had been there... It fits almost perfectly. At full curl the cylinders hit the loader frame, so I have to be careful how far I curl. I like the bucket so I'm going to make it work...

Not perfect but at least it's much improved. Oh, I also cleaned up the plumbing at the valve. It was a mess before and you actually couldn't reach the choke or starter button, so I used to have to start the tractor standing on the left side. Now I can start the tractor, work the choke, etc seated or standing on either side. Obviously it's a little bit of a reach for the right side. Oh, and I'm going to make a bracket to hold the new lift cylinder lines. I'm going to mount it to where the braces meet up in the center-front of the aux tank. Just a piece of angle iron probably with a couple U bolts to clamp the lines.

**Pictures and descriptions added**

Because of the single acting cylinders and double acting valve the PO was dumping the one side into the line connecting the aux tank and TC block fill port. I removed 8 quick connects, various unions, nipples and elbows as well as 3 complete lines... Of course I needed two extra lines for the double acting cylinders but I'm net -1 line from the PO's version.

The line with the T is the dump into the aux tank and TC block. The other line is the return from the valve to the bypass block. Both are in the way and make it impossible to reach the choke and difficult to reach the starter button.

Lines before

I changed fittings at the valve and moved the lines to the left side. The aux tank is now directly connected to the TC block with a single 1/2 line and my custom adapter so I get 1/2 through the whole line. Previously it was necked down to 1/4 inch and since it's gravity I didn't want the restriction. I removed all but two of the quick connects (10 originally) and used the female out of the pressure tap and a male on the end of the hose going back to the block. This way if I ever have to remove the loader I can just loop that line and have proper flow.

On the return from the valve I added a couple 90's so instead of making a big sweeping loop past the operator's station it goes left and down that side of the loader. The female side of the quick connect is on the valve after the two 90's and the male end is on the end of a 48" hose that is threaded into the block. I also added a 45 street elbow off the block because with the hose directly into the bottom of the block it was hard up against the engine/transmission casting. Currently it's the only 1/4 line on the tractor. All other pressure lines are 3/8 and with the 45 degree fitting I could add a reducer to go to 3/8 if I want, but honestly 1/4 lines are probably all the tractor needs.

The feed from the pump to the valve is the line that loops around over the fender. I had a 36" line but probably could use a 30" line. It's fine for now but I may switch that out down the road too.

Oh, and I permanently mounted the pressure gauge rather than use quick connects like the PO did.

Lines after

[ricky racer]