I finally bought a Gentec HT1440 thumb. I will be putting it on my CAT E70, rebadged Mitsubishi MS070. I had it welded on Friday. Hyd. system pressure is 2490. I'll be putting this relief valve in adjusted to 1800 psi.... Can I plumb the thumb relief line back to the tank relief valve with a T fitting? hugs, Brandi
I believe that would have you dumping unfiltered oil into your tank, wouldn't you want to tidy it up by utilizing an unused return port on your return manifold? Had a customer wad up a thumb cylinder piston , didn't know it til the arm shot out and stayed that way. $2800 cyl + 28000 MCV + full tank of hydro and hand washing the tank. Plus flushing twice . Very expensive shortcut.
Funwithfuel, Thanks. Actually, I have never plumbed a relief valve and never had a pressurized tank before. I'm not sure where the return manifold is. But I will find it or just plumb the relief line down to the belly and overboard where another one is located. Does unfiltered fluid go through the oil cooler? I see some hoses with worm clamps there that I could tee into. hugs, Brandi
Pressurised tank is nothing, its to prevent the pump from starving. That aside, yes , i believe the cooler is unfiltered oil. I don't think that's where you wanna be. From the cooler and the MCV there should be a large diameter manifold hugging the inboard side of the tank. On that manifold, there "should" be some unused bungs with caps. If you follow it back inside the tank it should lead to the filter well. Do you have the plumbing directions. I think your relief cartridge may only protect in the close function. Are you going to be readily changing out this attachment? For example would you use grapple and then follow with another implement which would be a higher flow and pressure, or would it be dedicated? The reason I ask is, you could effectively do everything you want with the port reliefs of the function at the MCV. This would protect both A& B circuits.
The only plugged ports I find is one on each Main Control Valve Bank. No where else could I find a port plugged. hugs, Brandi
So you have rigid piping running back to tank. That's rotten! Is there any place you can T into on that circuit? The bottom line is, you just don't want unfiltered returning to tank. This diverted valve you're trying to plumb in, is it a pressure reducer or a flow control. There's a difference. If you're just trying to reduce cylinder speed, you could just introduce a restriction. Control your pressure with the port reliefs . That could simplify things a lot. Maybe see what your implement supplier thinks of that solution.
Hey, it is Japanese. Yes, it is rotten. It is all hard piped BSPP -12 fittings and tubes. I'm installing a solenoid diverter valve. I'll route the bucket lines to it and run the bucket and thumb with the valve via a switch in the right control knob. I did the exact same installation on my tractor for my grapple. Except I didn't have BSPP fittings to deal with and the grapple doesn't need a relief vavle as the grapple and fixed tines don't hit. I have a plan for the relief. DC-9 airliners had a sump bottle in the wheel well. Overflow from the gear doors dripped into it. Every day we had to check and empty the bottle on our service checks. I will install something like that and vent down low. If the thumb is precise as my grapple, I should not have any problems where the relief valve vents. Thanks. hugs, Brandi
Just buy a small 10 micron spin on filter and head, put it inline between your new relief valve and the tee you install at the tank, change the filter when you change engine oil and when you pull it off drain it into a clean pan. If it has metal, tear down the thumb cylinder. You WILL have lots of oil coming through that relief if you're clamping stuff with the thumb and especially when you roll the bucket back against the thumb. Cheers, Lanway
So put a T under this relief valve, then put a filter between the T and the thumb relief valve? I like it. Thanks, hugs, Brandi
This filter assembly http://www.surpluscenter.com/Hydrau...GA-RETURN-LINE-FILTER-25-PSI-BYPASS-9-059.axd has a 25psi bypass. What happens when 1800psi relief pressure hits it? Or is this the wrong type of filter assembly? hugs, Brandi
Brandi, The relief has three ports, two of which are straight through so you put it inline with the hose going to the butt end of the cylinder. The third port has no flow and no pressure until the relief opens and then assuming you have properly sized hoses and adapters (fittings) the filter will only see tank pressure since that line is open to the tank where you tee it in. The 25 psi bypass is a small relief valve in the filter head that allows oil to bypass the filter element if it becomes plugged rather than allowing backpressure to build to the point where you get an external leak or an internal collapse of the filter media which would spread contaminant throughout the system. That filter should be fine for your thumb relief return.
Thanks! That is what I was thinking, just needed to go to bed. Sometimes, night shift just plain sucks. Thanks again, hugs, Brandi
You know, Iantraxco hit the nail on the head. A much simpler and cleaner solution. Wish I had seen it first.
Naw, it's just us poor folk have poor ways... necessity being the mother of invention, yeah? Cheers, Lanway
Yeah. I said to myself....Why didn't I think of that. Simple AND functional. hugs, Brandi
This is why I love this forum. Folks making simple suggestions that work. Thanks again, Lantraxco! hugs, Brandi
It is going slow here on all the plumbing. Lots of head scratching. I did get the fittings in and reused a Ford fuel pump bracket for a filter mount. I mounted the relief valve directly to the filter assembly and the relief will have 1 inch rubber under the relief. I'm raising the air filter for the relief line to the tank so the line will go under the air filter outlet duct. I also need to replace the air duct, so I took it off and found this rusted filter outlet. I'm sure these are not cheap, if I can find one, so I will see if my local welding shop and replace the outlet. hugs, Brandi
Looks good. Not that air cleaner though, gotta wonder how much rust has made it's way through the engine, there's nowhere else it could go?
That is exactly what I was thinking when I saw it. Right now I have a plastic cup and duck tape over the inlet. Then I disconnected the battery, so I won't have a mental lapse and try to fire her up. I'll get the air vac down in there next weekend to try to get anything still lurking down in there. hugs, Brandi
Do I need this filter condition indicator on the end that is rusted? I'm thinking of just cutting the damage off and the indicator off and getting a pipe extension to clamp on. It would be enlarged to 3 inch (muffler shop), as that is what the inlet to the engine is. The air filter assy. outlet is 2.25 inch. I guess it all depends on what flex duct I can find to replace the old duct hugs, Brandi
I cleaned up the air filter outlet and trimmed off all the bad metal. Next I got an adapter pipe from a muffler shop and notched out a slot for the indiacator and slotted the pipe so it could be clamped on tight. Then I added a heavy truck clamp and all is good. Now waiting on Caterpillar to get my new duct in. What can I seal the tiny slits that can let in dirt with? I'm thinking Silicone adhesive. Any other ideas? hugs, Brandi
The air filter is back together and raised 2 inches. Now the filter to tank line will go under the air duct to the engine. hugs, Brandi
Looking good!
Thanks. Just waiting, and waiting on CAT to get the new air duct in. hugs, Brandi
Does look good. You'll be having a working thumb in no time. As a messy alternative to silicon adhesive, the bridging filler body shops use that has the glass fibre strands in the epoxy gunge, good for gloming up holes in air filter housings. But yours now looks too tidy to want to do that.
Thanks John. On a different note, CAT has frozen my air duct order. It's on the shelf and CAT won't sell. See my post here............. HeavyEquipmentForums hugs, Brandi
Does anyone know where I can get 3/4 inch ID tubing? I need two pieces 11 feet long for hard lines going over the boom. I will form it and bend one end at 45 degrees. They have my local welding shop weld these JIC fittings on the ends...... https://www.discounthydraulichose.com/product_p/6400-08-08.htm hugs, Brandi
Maybe: https://www.tmhyd.com/ Make sure the tube or pipe you get is seamless and rated for hydraulic use and 3,000 psi minimum safe pressure?
Thanks. This outfit is a few miles from where I work.Yes to seamless and rated for at least 3,000 psi. hugs, Brandi
This outfit is only 18 miles from the hangar. I called this morning and they do have 3/4 OD tubing in stock. Only thing is it is over $9 a foot. Yes.... 9. I'll be there when they open in the morning. Thanks again. hugs, Brandi
Ouch... well if they have what you need you gotta figure what your time's worth wandering around looking elsewhere for it... Git 'er done!
The air intake hose came in today. Here it is with the air filter assembly raised 2 inches. hugs, Brandi
I was in Alvin, Texas today at Tubing & Metric Hydraulics. I bought two 12 foot lengths of 1/2 inch .065 wall tubing and 4 tube end adapter fittings FL-2000-08-08. The tubing was $4.67 a foot and the "compression" adapter fittings were $11.84 each. hugs, Brandi
That sounds better!
Thanks again for the link to them. How did you find out about them? hugs, Brandi
I am a Ninjitsu master of Google-fu, lol
What key words did you use? Or did you sleep since then and forget? hugs, Brandi
hydraulic tubing willis texas I was a parts man for several years, I've trained my brain to forget as soon as I hang up the phone believe it or not, lol
Lantraxco, Your a hoot and a half! hugs, Brandi
LOL, I think I'm pretty boring in person, but then the only reason the baby's mother sticks around is I make her laugh so mebbe not?
Oh I am sure you are laughable. If I am thinking and saying that right. hugs, Brandi
I have been busy today making clamp brackets. Here is what I got so far. The boom side mount bracket and the QD bracket will have tapped holes in 1/2 inch plate that will be welded on. hugs, Brandi
..............and here is the QD Mounting Bracket. Small X about a foot in front of the T is where the QD bracket will go. hugs, Brandi
Looks good to me!
Thanks. hugs, Brandi
The 1/2 inch line clamps came in yesterday. Since I was off tonight, I got to weld them to the brackets and installed, along with the QD mounting bracket and plates. hugs, Brandi
I finished the hard line installation. I removed the QDs and went with hard connections. Keep it simple, right? Saturday evening I finished all the wiring and fired it up. No leaks, but my control inputs to close the thumb did not match the input to close the bucket. So I swapped those lines and all is find. Now I need to order a T to plumb the relief valve to the correct line. The thumb movement speed is good, not too fast and more important to me, not too slow. I was afraid the 1/2 hard lines would make it too slow and I would have to change everything to 3/4 inch line and hoses. I still need to paint the hard lines and add a handful of hose clamps also. hugs, Brandi
Now that I swapped lines and got the thumb closing with the same control lever deflection as the bucket, the thumb, when retracted, leaks down as soon as I release the switch button. Today I took the relief valve hoses and looped them and ran the hoses to the thumb without relief. Now when I take my finger off the button, the thumb stays retracted. When I sat the pressure on the relief valve, I counted the turns from full open and closed and divided by the psi range and thought I had it right at 1800 psi. What can I do to get the relief valve back into the circuit, yet keep the thumb retracted? Do I need a check valve in that circuit also? Right now I'm painting the hard lines and I can't play around with it to figure it out. All help will be deeply appreciated. hugs, Brandi
Can I use the relief valve with one port plugged. Something like this.......... hugs, Brandi
No offense, but that's a mess and would not be helpful. What were you thinking with the check valve exactly? Do you have a check valve somewhere in the system now, and for what purpose? The relief valve should be in the line to the butt end of the cylinder, one through port connected to the diverter, the other through port connected to the line leading to the back end of the thumb cylinder. If that's the way you had it connected, you have another issue because the rod end is what holds the thumb retracted.
When I first plumbed it, the line from the diverter went through the relief valve and then to the butt end of the cylinder. Plumbed that way, the thumb held it's retracted position. But the control movement to close the thumb towards the bucket was opposite to closing the bucket towards the thumb. So I swapped thumb hoses and the controls matched, ie.....move the control lever to the left and the bucket closed. Then hit the button while holding the control lever to the left and the thumb closed. But when I retracted the thumb and released the button, the thumb would start bleeding down. So I looped the relief valve line to see if it still bled down and it didn't. So that told me pressure holding the thumb retracted was leaving via the relief valve. So it seems the relief valve is adjusted wrong or not closing all the way. Guess I need to install a gauge on a T fitting to check it out right. The diagram above was just a theory to run past Y'all. I realize now the check valve would not work at all. hugs, Brandi
I took the relief valve to my local hydraulic shop, this morning, and had it adjusted (professionally) to 1800psi. He didn't charge me. I asked if I could plug one port on the relief valve and add a T. He said yeah. Just got it all back together and all is working the way I want it to and relief is just on the line to the cylinder's. One less hose to worry about also. The thumb was still fully retracted when I came in for lunch. Will see shortly if it bled down any. hugs, Brandi
The thumb was still up after an hour lunch break. It only dropped down 3/4 inch. I can live with that. Here are photos of the hose T mods. hugs, Brandi
I haven't read the thread, but I have an E70B with an aftermarket thumb and if anyone wants I could take some pics and trace some lines.
Oh wow. I am done with my install now, but would love to see the photos of all components. Especially were machine pressure enters the thumb circuit. Also, photos of your CAT would be welcome also. You can post them here, or start a new thread. If you start a new thread, please leave a link here. hugs, Brandi
I'm looking to do the same thing but on a 200 class excavator. Does anyone know of a source for a large valve?
Google what type of valve you need with your system psi and gpm. Also include pilot or electric. Something should pop up to get you started. I got lucky in that my system pressure is 2450, so I could use diverter valves mostly used on tractors. Did I say I love my CAT?
I guess I should have done this before you started. See the tee on top of the rotary manifold/swivel? The horizontal line on the tee connects to the top left side of the diverter valve (I guess that's what it is). My thumb is not near as fast as a factory thumb but get's the job done. I even get to show off the views from my place.
Thumb mount details:
I gather your machine is truly an E70B. Mine is a rebadged Mitsubishi MS070. My machine has the valve banks right behind the house and huge structure for the boom mount enclosing the area around and above the rotary valve. I am interested in your (what looks like a) quick coupler. Did you make it or did the thumb installer make that also? Can you take more photos of the coupler? I want to make one for my machine. hugs, Brandi
Bindian, As far as I know it's truly an E70B grey market Cat. Under the yellow paint it's blue. and has Japanese writing all over it. I believe it's a 1992 model. The quick coupler I can describe in 3 words "I hate it". It's the sloppiest thing on the machine and I wish it wasn't on there. It holds the bucket firm as a dishrag. Unfortunately removing it requires considerable modification because the thumb linkage has been made to accommodate it. I can take pics of it tomorrow. If you install a quick coupler on yours now, the existing thumb will have a serious underbite. Couplers change all the geometry and add a lot of weight, which may be one of the reasons my swing brake is on it's last leg. My thumb is also extremely heavy, maybe it came off a larger excavator.
I thought about underbite. I would add longer teeth to match the thumb. I'll see how it digs now with 250 pounds extra out there. I don't change the bucket too often, but when I do it's a fight getting the orings to stay rolled over the flanges until I get the pins in................without breaking them! I have got pretty good at rolling the orings. Then bunches of changes were made since mine was built. I think mind is a mid to late 80s. Do you have a data plate, or did CAT remove it? Mine is gone. I had to weld a made up number on the frame from insurance. Far as I have seen, mine is just yellow with black trim. hugs, Brandi
[ Here's the pics of the quick coupler. I can't make out the logo, someone here may recognize it though.
One more...
Also, for got to mention, "overbite" or "underbite" depends on where your bucket is curled so they can be used interchangeably. If you install a coupler I think you'll have to lengthen the thumb.
Thanks for the photos. As mentioned above...........I would add longer teeth to match the thumb. hugs, Brandi
The teeth on the bucket will protrude farther than the thumb. Adding a quick coupler will increase the radius of the bucket. Look how long my thumb is made to accommodate the added length of the coupler.