A Tandem Cub - Page 16

sawdustdad · #**151** 01-09-2018, 06:56 PM

I realized the cover of the transmission is too thin to tap, so today I found some hydraulic bulkhead fittings. I'm working to find the necessary flare nut (NAPA had the bulkhead fittings but not the flare nut, go figure) so I can attach a dip tube to one. Local hydraulic shop about 10 miles away, headed there tomorrow.

I'm now planning on mounting the pump under the crankshaft with a bracket attached to the frame. Engine is not tapped and has a starter pulley/PTO basket on it anyway so I will belt drive it. Could use a PTO but then I'd have to worry about interference with the PTO actuator lever and rockshaft in locating the pump.

I ordered a double acting single spool valve with spring loaded center detent, 3000 psi internal relief.

I found some used golf cart seating that I'm going to try to use. Not real sure yet how they will work out, and they are not new by any means, so I'm not sure I'll keep them.

Didn't get much done in the shop due to running all over town, welded the corners on the front hydro trunnion (not bad to begin with) and painted some of the subframe and foot pads black.

J-Mech · #**152** 01-09-2018, 09:00 PM

Quote:

Originally Posted by sawdustdad

I realized the cover of the transmission is too thin to tap, so today I found some hydraulic bulkhead fittings. I'm working to find the necessary flare nut (NAPA had the bulkhead fittings but not the flare nut, go figure) so I can attach a dip tube to one. Local hydraulic shop about 10 miles away, headed there tomorrow.

I didn't mean to state the obvious. I assumed you knew the cover was too thin to tap..... but never a bad thing to be thorough.

FWIW, you don't have to use a flare nut to make a dip tube. I know what you are thinking.... I'd just drill a hole and run a pipe into it and down into the oil. Weld the pipe to the cover. Doesn't have to be schedule 40 pipe for the suction. You can use thinner stuff. On the return, a pipe bung will be fine. It just has to get the oil into the case.

Quote:

Originally Posted by sawdustdad

I'm now planning on mounting the pump under the crankshaft with a bracket attached to the frame. Engine is not tapped and has a starter pulley/PTO basket on it anyway so I will belt drive it. Could use a PTO but then I'd have to worry about interference with the PTO actuator lever and rockshaft in locating the pump.

Good plan!

Quote:

Originally Posted by sawdustdad

I ordered a double acting single spool valve with spring loaded center detent, 3000 psi internal relief.

3000 PSI relief is too high. Most are adjustable. I would trim it down to around 1000. If you need more, you can always bump it up. Too high and you could tear up the bed if the load is heavy. Don't want the hydraulics stronger than the structure.

sawdustdad · #**153** 01-09-2018, 11:03 PM

Quote:

Originally Posted by J-Mech

I didn't mean to state the obvious. I assumed you knew the cover was too thin to tap..... but never a bad thing to be thorough.

FWIW, you don't have to use a flare nut to make a dip tube. I know what you are thinking.... I'd just drill a hole and run a pipe into it and down into the oil. Weld the pipe to the cover. Doesn't have to be schedule 40 pipe for the suction. You can use thinner stuff. On the return, a pipe bung will be fine. It just has to get the oil into the case.

3000 PSI relief is too high. Most are adjustable. I would trim it down to around 1000. If you need more, you can always bump it up. Too high and you could tear up the bed if the load is heavy. Don't want the hydraulics stronger than the structure.

In order to make up the hydraulic suction and return lines to the transmission, I decided just to stick with hydraulic connections to simplify the overall plumbing. I don't want dirt to contaminate the fluid, so the bulkhead connections seal with an o-ring. Agree they are under no pressure, but just want it to be secure.

I'm wondering if I need to add a separate vent to the gear case? What do you think about that?

The valve does have adjustable relief settings. You are right, no sense setting it higher than needed. That's good advice. Thanks.

I am planning to use a 3/8" line for pump suction and 1/4" lines for everything else. The fittings here are 1/4 inch, but I'm going to increase the size of the one with the dip tube to 3/8. 1/4 inch seemed too small and I don't want to starve the pump suction.

Pics: Transmission case cover has been removed, cleaned and prepped for the fittings. It's back on loosely to keep dirt out of the case.

bulkhead fittings so you can see how the suction tube will be rigged, though the 1/4 in fitting will be upgraded to 3/8 when I can find the necessary flare nut.

the used seats I found today. I'm not happy with them, so I may try to find something else, but if I can't find anything better, I'll use these and perhaps recover them.

J-Mech · #**154** 01-09-2018, 11:13 PM

I think going to a 3/8" line is a good idea. You sure that's large enough though? What size is the pump inlet? Just asking....

Another question: What are you going to do for a filter? Don't forget that.... If it was me, I'd run it on the return from the valve. You can mount it under the bed somewhere that way, and you don't have to worry about it impeding suction. I'd get a base that will accept the 1410 filter that the hydro uses. That way you don't have to stock another filter.

On the vent: No, I don't see the need. Fluid is still moving, but going back into the case, so air movement should be minimal. If you want to, you can change it, but it should vent fine. Just make sure the current vent is clean and clear and you should be fine.

Sorry the seats didn't work out. I hate that when I get an idea.... then it doesn't work like I had hoped. I like fabrication though.

sawdustdad · #**155** 01-09-2018, 11:22 PM

1.5 gpm is pump max capacity at 4000rpm. Pump itself has 9/16" fittings.

I figure that's not much flow and the pump will be below the reservoir, so once the line is full, it should stay primed. Trying to keep the line size small to make them manageable to route and to keep the cost down.

Why do I need another filter? The hydro fluid is filtered already. I can see a strainer on the suction line, but it's just a gear pump. Wasn't planning for another filter. If I put a filter on it, wouldn't be best to have it on the pump suction anyway? To keep debris out of the entire lift system. No?

J-Mech · #**156** 01-09-2018, 11:54 PM

Quote:

Originally Posted by sawdustdad

1.5 gpm is pump max capacity at 4000rpm. Pump itself has 9/16" fittings.

I figure that's not much flow and the pump will be below the reservoir, so once the line is full, it should stay primed. Trying to keep the line size small to make them manageable to route and to keep the cost down.

Why do I need another filter? The hydro fluid is filtered already. I can see a strainer on the suction line, but it's just a gear pump. Wasn't planning for another filter. If I put a filter on it, wouldn't be best to have it on the pump suction anyway? To keep debris out of the entire lift system. No?

If you have cavitation issues, you could always check the suction side for vacuum. I dunno.... 9/16" on the pump.... should probably be 1/2" suction, and 3/8" pressure. I'd have to check a chart, or see what the pump manufacturer recommends.

Why do you need another filter..... because it's a separate system. Yes, the rear end fluid is filtered.... before the pump. So any wear, or contamination ends up in the reservoir, and gets filtered before it starts the cycle again. By all rights, you should run the filter before the pump since the other system is that way. Not uncommon for filters to be on the return side though. That way, reservoir fluid is always clean. I have mixed feelings..... you could run it with no filter and likely never have an issue. Especially if you don't pull from the bottom of the reservoir. Keep the suction tube off the bottom, and you will probably be fine. Since the other system is a suction side filter, If you add a filter, you should probably set it up same with this additional system. Again.... I know it's a pain, but you really should have a filter. I won't complain either way. If it was mine, I'd filter it.

sawdustdad · #**157** 01-10-2018, 12:13 AM

Was on McMaster ordering the pulleys, and saw an inline filter, with a replaceable element, rated 12gpm. 9/16" fittings. So I'll put that on the suction side of the pump.

DieselDoctor · #**158** 01-10-2018, 10:28 AM

Looks good so far Frank! Not to bend your wallet any further, but because your pump and filter are going to be below fluid level, you may want to install a simple shut off valve in the line. Changing a filter with oil flowing can be a real mess, and also should something be damaged you can stop the flow of oil. Just a thought. Isn't it fun how costs in a simple project add up?

DoubleO7 · #**159** 01-10-2018, 06:41 PM

Is there not a built in, vacant pulley on the output for driveshaft?

To drive the optional IH Hydro Pump.

The pump you bought appears to be small enough it could be mounted straight above or below that pulley.

Or maybe the diameter is too small?

Nevermind, your post (#44) appears to show no vacant pulley on your K301 but you could swap one onto it from another engine.

sawdustdad · #**160** 01-10-2018, 06:48 PM

Quote:

Originally Posted by DoubleO7

Is there not a built in, vacant pulley on the output for driveshaft?

To drive the optional IH Hydro Pump.

The pump you bought appears to be small enough it could be mounted straight above or below that pulley.

Or maybe the diameter is too small?

Do not have a pulley on the flywheel side.