Rebuilding The Hydraulic System on A TerraTrac Crawler

[Iplayfarmer]

I've decided that it may be easier to consolidate my progress and questions by making one thread about rebuilding the hydraulic system on my TerraTrac GT30 crawler. Thank you to all for your input on my other two threads here in the Hydraulics forum. In keeping with the status quo on TractorByNet you've helped me to spend more money than I had originally planned. I ordered two double acting 34" stroke cylinders that should arrive sometime next week.

The attached picture is of the culmination of an entire days work. I took yesterday to measure, mark, and calculate what the bracket would need to look like in order to mount the new hydraulic pump so that it AND the alternator can both be driven off the fan belt. It doesn't look like much, but I consider it a masterpiece. I'm sure I'll have to modify something on it by the time this project is over, but for now it's great.

I had some questions about the size of my valve, but I think I've resolved them. The pump I bought says that it's rated for up to 10 GPM, and the hose size guide says that I need larger hoses for that kind of flow. But, the pump's suction and pressure openings are the same size as the fittings on the valve I have to use, so I'm going to go with it.

What has filled my idle thoughts today has been where and how to mount a filter. I'm sure I want it after the tank before the pump suction port. The most likely place is out on the front of the crawler. Is that a bad idea? Do these filter have to be mounted right side up, or can I mount it sideways?

The other challenge I'm going to face is routing hoses for the lift arm cylinders. The older cylinders were single acting, and the new cylinders are double acting. I'm going to need a place for another two hoses. The current configuration includes a hard line plumbed across the front of the operator station. I may try to add a second hard line since I think that would look the best. Can good old galvanized pipe be used on a hydraulic system?

 

[oldnslo]

Do not use galvanized pipe or fittings for hydraulic lines. The galvanize coating will come off destroy your hydraulic components.

What speed - RPM are you spinning the pump? Take RPM times displacement in cubic inches and divide that sum by 231 to arrive at GPM pump flow.

For pump inlet line size do not exceed flow velocity of 4 feet per second preferably less to prevent pump cavitation.

Filters can be mounted horizontal but be sure to protect it from branches, etc.

 

[Iplayfarmer]

I知 not exactly sure what speed it will spin at yet. First I need to find the speed of my engine. Then I can calculate based on the ratio of pulley sizes. I知 assuming I値l be in that 2,000 rpm range.

 

[WranglerX]

I would avoid any galvanized fitting and/or any "pipe" fittings..... Only buy high pressure approved fittings from hydraulic equipment supplier....

Dale

 

[Iplayfarmer]

Some updates on my progress. I got the bracket painted and installed. I was right in predicting that I'd probably have to do some modification. The pump mounts fine and clears everything, but the pullet interferes with the radiator hose. I raised the bracket up so that it mounts on just the two upper bolts, but now I need to fabricate some a new mount for the alternator because it too must go up. I may end up back at the drawing board completely. If I can't get the alternator to play nice I may end up swapping and putting the hydraulic pump on the top and the alternator on the bottom.

I did measure my crankshaft pulley last night, though. It's 6" diameter. My pump pulley is 4" diameter, so that puts my pump speed at half again the speed of the engine. At 1600 rpm engine speed I'll be spinning the pump at 2400 rpm. In the end It may work better to get a larger diameter pulley to slow down the flow.

The attached picture is of the pump mounted in the engine bay BEFORE I saw the interference and raised it up.

 

[Tinhack]

When I built the "Kenbota", I put the filter line on the output port of an open center valve. Plumbed to a convenient location, of course. The outlet side of the filter went to the tank. You could also put a cooler in this line as it's low pressure at that point. The tank is expected to always have clean oil. You also don't want anything (except maybe a strainer) restricting the suction of the pump. A soft suction line will collapse. That's what was happening to my JD dozer with an old 1 1/2" suction line. The old rubber just got soft. Pretty pricey replacement too.

This shows the location of my Kenbota hydraulic filter.

 

[Iplayfarmer]

The tank for this machine is actually the inside of the loader frame pipes, and it hasn稚 been used for a while. (The crawler came to me with a dump trailer style electric over hydraulic system.). I may mount the filter between the tank and pump temporarily until I?m confident that any dirt and debris have been cleaned out. Then that system with the filter between the valve and the tank makes a lot of sense.

 

[Iplayfarmer]

On another note, I decided to add an idler pulley to my configuration. When I got the alternator and the pump set in place the belt was only engaging with about an eighth of the pulley. Adding an idler will get more belt to pulley contact AND give me an easier way to tension the belt.

 

[Iplayfarmer]

I have a few updates to this TerraTrac project. I took a few weeks off of work for Christmas, and carved out some time to work on it.

First of all is the final bracket assembly for the pump and alternator. In the end I feel like a GM engineer... I over-complicated things and managed to have bolts that are almost inaccessible. But, everything fits, and the belt has pretty good engagement with the pulleys. I still haven't run anything yet to make sure the belt stays where it's supposed to be, but things look lined up and secure when I poke my head in there. I have included a few pictures of the final bracket assembly. Between the two pictures hopefully you can see the details of how it all goes together. You can also see from these pictures that I am not working in any kind of heated shop like some of you have. I do have a roof over me, but there's no shortage of snow and ice that ends up on the machine in between working on it.

The other tidbit relevant to the engine bay installation is that I received the bearing for my outboard pump bearing. This is the bearing that I had to order from the UK. To my relief it fit pretty well. I did add a little locktite to the outside race of the bearing just to give a little extra security. It seems like it's going to work how I need it to. I plan to be careful about tightening the belt too much. This is as much for the lower crank bearings on the engine as it is for the pump. I guess if I have issues with slipping I'll troubleshoot when it happens.

 

[Iplayfarmer]

I'm breaking the progress report into a few posts to make it easier to see what pictures go with what part of the description.

While I had the engine bay all torn apart I decided that there would never be a better time than now to rewire the whole machine. With the exception of the main battery cable, I replaced every wire on the machine and ran it all through plastic looms. It really improved the look of things, but primarily it should prevent problems that were inevitable with the old, frayed, brittle wiring that was in there. Part of this process was to add headlights to the front as well. These are vintage fixtures that I've had on my shelf for years. My hoarding tendencies have, once again, been validated.

I added new switches, new gauges (including oil pressure and coolant temperature lines), and I added a fuse block. As a side note, I also replaced the carburetor with a new Kipa carb from Amazon. I had to do a lot of measuring and researching because there's no cross reference table for these old TerraTrac crawlers, but I ended up getting one that fit "mostly". I had to keep my old throttle and choke linkages to maintain compatiblity with the controls on the dozer, but the rest of the carb matched up just fine. I still have not tested anything because I don't have any hoses run to the pump, and I don't want to run it while it's dry.

The new headlights on the crawler make it look like a snail in my opinion. Another guy said it looks like the shrimp off of "Finding Nemo". The second picture is of the new gauges, and you can kind of see the wire looms underneath the dash plate.

 

[Iplayfarmer]

The final installment of this progress report is the installation of the valve and the lift cylinders. Once again, many of the components for this hydraulic re-build are coming from an old Jacobsen reel mower. The valve is no exception. It took a little imagination and a lot of clamps, etc., but I got the valve welded to a plate in such a way that It mounts cleanly on the loader frame. It bolts on, so I can remove it if needed. I'm only using two of the three cylinders for now, but if I succeed in acquiring or fabricating a 6-way blade for this crawler, I'll need the third spool.

I bought the double acting lift cylinders from a company I discovered on ebay. The front of the cylinder mounted up nicely, but the back was wider than the existing mounts. I passed the point of no return on this project when I cut the old mounting brackets and welded new pieces on to make the new cylinder fit. There's no going back now.

At present I am debating through the "what tank do I use" dilemma. I can get the 6 gallons that I need (pump is rated for 6gpm) by combining a little 3 gallon tank that I have with the internal capacity of the loader frame that was part of the original system. Or, I can use the 13 gallon tank from the Jacobsen mower. The Jacobsen tank would have to mount behind the seat and hang a little out the back. I know that the large tank is more likely to perform well, but I'm not sure I want the look of a tank hanging off the back of the mower. I'd love to hear opinions.

Once I sort out the tank dilemma I get to go through all of my hoses and see if I have the lengths that I need.

 

[Iplayfarmer]

Question: How do I tell what direction the flow should be on a hydraulic fluid filter housing? I have an old housing from the Jacobsen mower, but I don't see any arrow to indicate flow direction.

 

[Tinhack]

Question: How do I tell what direction the flow should be on a hydraulic fluid filter housing? I have an old housing from the Jacobsen mower, but I don't see any arrow to indicate flow direction.

I believe the center is typically the output (from filter). The filter takes the dirty oil in on the sides since the pleating surface area is larger. If you have a loose filter housing, put your finger in through a hole. If your can see your finger, that's the input side.

The output side is usually the filter threaded post. You could also blow air in that to find which side port is output.

 

[Iplayfarmer]

I believe the center is typically the output (from filter). The filter takes the dirty oil in on the sides since the pleating surface area is larger. If you have a loose filter housing, put your finger in through a hole. If your can see your finger, that's the input side.

The output side is usually the filter threaded post. You could also blow air in that to find which side port is output.

Thanks. I can see from the inside which goes to the center and which goes to the outer surfaces of the filter. This helps.

 

[Iplayfarmer]

Now that I have the filter thing figured out, does anyone have some good advice for cleaning out the lines, valve, etc.? The old donor machine sat for a lot of years, and I want to flush the lines somehow before I connect them to the new pump. Is this something that diesel fuel would be good for? Is there some kind of cheap little pump that would do good?

 

[Peter 315]

You can use diesel fuel and a drill pump......http://https://www.homedepot.com/p/Everbilt-Drill-Pump-Kit-PUP63-HD/204667248

 

[Iplayfarmer]

Here's a bit of an update on this project. I went a little less intense with cleaning the lines, and I just use compressed air and a rag to get the bulk of the debris. I am hoping that anything I missed gets caught by the filter and the screen in the tank.

I have used about $100 worth of adapters so far, and I think have all that I need. All of my fittings are ORB and all of my hoses are O-ring face seal. There are three fittings that I can't get locally, and I have ordered them from fittingsandadapters.com. I have never used them before, but they looked legitimate. I was satisfied with their system of organizing things in a way that was easy for me to find what I needed.

Call it luck or call it providence, but I used up every 1/2" hose that I could pull off the old mower, and I had exactly what I needed. It was a bit like playing "Go Fish" to arrange hoses where everything would work, but in the end I'm happy with how stuff is layed out. I'm still waiting on those last few adapters before I can start the machine and see if anything I have done actually works.

One problem I did identify without running the machine is that the old valve placement would have been uncomfortably close to the lift cylinders at full height. I decided to play it safe and just re-oriented the valve horizontally rather than vertically. I'll likely heat and bend the valve handles at a later date to get them pointing up. I don't know if there's any advantage to the handles pointing up, but it's what I'm used to on my other tractor.

I've attached a few pictures to show the current progress. Unfortunately it seems like there is never a good way to route hydraulic hoses without thinks looking like chaos.

 

[Iplayfarmer]

This is a follow up for the record about fittingsandadapters.com... I think they are out of business. The website is super helpful with resources for finding the right sizes of hose and fitting, but there is no one on the other end whether it be via e-mail, phone, or chat. My credit card showed a pending charge for a few days, but it was never actually charged. I got the email saying "thank you for the order", but no shipping email. Multiple attempts to contact the business have failed. It's too bad because it looks like someone with some genuine knowledge and experience set it up.

I'm not out any money, just time waiting for nothing to come. I finally went to a different local shop who suggested using a few adapters in combination to get me to the setup I need.

The crawler is now fully reassembled for test fit. Now I will probably spend some time going back through the hoses and doing an extra clean on them to minimize the potential for contaminants in the system as much as I can.

 

[Iplayfarmer]

It seems like I have lost most of the audience on this thread, but I'm posting an update to my update about fittingsandadapters.com. 11 days after the initial order was placed, and after multiple attempts to contact them via chat, email, and phone; I received an email saying that my order shipped. My card was billed, and the parts that I no longer need arrived. When I got the email saying my order shipped, I tried again to contact them, but I was not surprised when I received no response. I mailed them a letter expressing my disappointment. I cannot recommend doing business with them.

 

[Iplayfarmer]

While I'm in here ranting about the fittings supplier, I should probably post an update on the project...

The valve that I scavenged off of the mower has some interesting float functions that don't work for a loader. The lift spool floats up (i.e. the valve will produce down pressure, but won't hold it), and the curl cylinder floats down. I also was only getting about 3 gpm, and the lift cylinders were VERY shaky on the down stroke.

I upgraded my suction line from 1/2" to 3/4", and this increased my flow significantly. I also purchased a cheap eBay valve to go with my cheap eBay cylinders. I'm getting 6 gpm now, and the loader functions like it should. The new valve eliminated the shaky down stroke of the lift cylinders.

At some point in the future I will probably upgrade my curl hoses to 1/2" to match the rest of the system. I have smaller lines there right now. The speed of the cylinder is fine, but I can hear the engine bog down when I run that spool, telling me that the restriction from the smaller lines is too much.

I still have little incidental stuff to do, like strap my tank down and zip tie the hoses to each other and to frame pieces where I can. But, in general, I'm considering this project successfully completed.