I am having a hard time figuring out what is needed to remove the clutch compartment drain plug. Someone elsewhere said it takes a 3/4” square drive to remove the plug, but the one I have is too small and I cannot find anything that will work. Anyone know what tool it takes to do so? My main goal is to just check and ensure no fluid is leaking into the clutch compartment. Having other issues and trying to check this to eliminate it from the equation..
Do you mean the steering clutches or the bevel gear? If you have dry brakes, you can remove the brake band support bolts to check for water, oil or any other types of fluid. If a compartment is filling with additional oil, the oil should be getting lower from where it's leaking. Bevel gear has a dipstick to check oil level.
Thank you and good question: trying to check the steering clutch compartments. I am trying to ensure there is no liquid/fluid in there. Great idea on simply checking bevel gear level. Will do so accordingly to eliminate that from the equation. Are there any other fluids that could possibly leak into steering clutch compartments? Lastly: could I just drill out a hole to let any other fluid that gets in there out from time to time? I have learned since my original post that the drain plugs are boogered up—not going to be putting any attachment on there to take them out in a friendly manner.
If you have dry breaks there will be a brake band support bolt on the bottom that is normally easy to remove. First thing to do is see if your machine has the support bolts to indicate dry brakes. If they aren't there you have wet brakes and the compartments hold oil. Don't drill in anything. The support bolts have a square head and lock nut and also have a ring around them like the drain plugs. If you don't have at least an owners manual, you should get one. Clutch cylinders could possibly leak into clutch compartments or bevel gear could have leaky seals. What issues are you having that you want to check for fluid in the clutch compartments? That's the best place to start.
Looks like an Allen,hex plug to me
There is definitely a bolt underneath each of the clutch compartments right next to the drain plug. That means I have dry clutches and brakes, correct? I do have the maintenance and parts manuals, but that’s it. I assume you mean service manual when you say owner’s manual. Let me know if wrong. When you say clutch cylinders could be leaking, I assume that to mean there is a hydraulic cylinder in each clutch compartment for the brake/clutch group. I don’t know much about how that works, but most of the tilt/angle/lift cylinders have been leaking. Good possibility cylinders would be leaking inside clutch compartments too if that’s the case which is why I am trying to figure out if there is fluid in the compartments. Here is what kickstarted this: the right track (from the perspective of sitting in the operator seat) in reverse doesn’t stop all the time when I push the right pedal. The left track going forwards doesn’t stop turning all the time when the left pedal is pushed. They do stop all the way or part of the way sometimes when under a load. They also do stop for a few minutes when the dozer has been sitting for some time and is first fired up. But, after usage and under certain conditions (or even intermittently) the tracks don’t stop when pushing the pedals. So, I was thinking maybe fluid had gotten in the compartment and started messing up some of the clutch plates. If I am rolling backwards on a hill in neutral and push the center pedal, the brakes engage and I can stop. Hope that makes sense. I realize my ignorance is showing in my explanation and I appreciate your grace and patience in assisting!
Thank you! I tried a 7/8” and 1” allen today to no avail. Neither really fit, and the shape isn’t uniform around the opening. I think the guy that owned it before me did a number on the plugs and boogered up in trying to get them out at some point. Just my guess based on the shape they’re in.
If you have to get it out you can clean it up and weld a nut on it
The brake band support bolts are the easiest way to check for fluid in the steering clutch compartments and wet brakes don't have them. When putting back in, you put them up snug then back off 1 1/2 turns. Your brakes could just need adjustment. Look in the archives on here for D3B or 931B brake adjustment. I meant owners manual that will tell you what maintainence is required. You need to check your steering clutches are operating properly too. Too much for me to try and find and post it here. The rollers on the steering clutch valves could be worn out and the steering clutches aren't fully releasing.
Great idea--thanks!
Confirming: I can just take the brake band support bolt out from underneath the dozer without any issue or other consideration? Makes sense putting it back in and then backing it off 1.5 turns. Thanks for the tip on the brake adjustment as well and checking the steering clutches and roller clutch valves. Have some work cut out for me this weekend. Thanks again!
The brake band support bolt can be taken out but be careful, if there was moisture in the case(s) they could be rusted so may need to be heated. I replaced mine and ran a tap to clean up the threads. Then I put anti-seize on the new bolts. I think you have a bunch of other things to check before you need to worry about getting drain plugs out. If you drive and push the outer pedals half way does the machine come to a stop? That would indicate your steering clutches are working properly. If they aren't completely releasing could make it difficult to turn because the sprocket is still trying to turn under power.
Regarding other things to check before the drain plugs: agree 100%. Not even thinking about that any longer.. Thanks for the heads up on possible rust from moisture and anti-seize. Great insight. Also the detail regarding pushing both outer pedals simultaneously to check the steering clutches is golden. Thank you for that! Looking like it’s going to be next week before I can get back out there do anything further. Will post with an update once I have it. Thanks again!
And also, those should be wet clutches. There will be oil in there
If you have the brake band support bolts you HAVE dry brakes. Wet brakes were optional and don't use the support bolts.
Guess I missed the brake support bolts. So if indeed you have dry clutches, I drilled a hole in my old 70s D3 to facilitate air flow and water drainage. I just periodically made sure the hole was open with a small screwdriver.
That’s what I was thinking. I could drill it, put a thread on it and put a small bolt in the hole for easy checking in the future. A bolt in it as well at least keeps dust/dirt from coming into the compartment while running it vs. leaving it open. Just my thought when I get back to this part of my issues..!
You don't want to leave it open. From the factory it came with some kind of corrosion preventative in the clutch cases but not sure exactly what. The support bolts are a simple enough way to check for any type of fluid in the clutch cases. If water is getting in something needs to be sealed better. If oil is getting in either the cylinders inside are leaking or the final drives or the bevel gear seals are leaking. I think you're getting too far ahead of yourself. Check the rollers on the steering clutch valves after seeing if any fluid is in the compartments. How many hours are on the machine? Look in the archives on here. AllDodge did some work on his brakes and steering clutches not long ago but his machine has wet brakes. The clutch valves will be similar though. I had my clutch valves rebuilt and rollers replaced but also had to have my steering clutches rebuilt and it was about $3500 per side. While the steering clutches were out I had new brake bands installed. It steers with light toe pressure now. HeavyEquipmentForums
I have searched and cannot pinpoint exactly what this is. I hate to ask, but what and where are the rollers, and how do I know if they are worn? From what I can tell in the steering clutch valves will be under the floor board/seat area. I assume the rollers are directly attached to the valves under the floorboard too? Assume also that “worn out” means they are flat vs. circular perhaps?
The steering clutch valves are under the floor board below the seat . AllDodges thread shows them. There are little rollers on the front that get flat spots and you need a press to replace them.
I think I have found the part. See the attached. Does this look to be correct? It's a combination of the CAM, the pin and the roller on the steering valve. I circled the part numbers I believe to be the parts (9, 17 and 18) I need to inspect once I start taking the thing a part. Please confirm.
Yes, check #17 for flat spots.
Perfect--thank you! I will be out there Wednesday doing the following and will keep you apprised: 1) Removing the brake bolts to see if any fluid comes out. Tightening back down the brake bolts and then pulling them back out 1.5 turns 2) Performing the brake adjustment procedure 3) Checking #17 for flat spots Going to be a fun day. Wouldn't be able to do it without your guidance thus far.
Caterpillar has a special tool for drain plugs. It is reversable because each side is a different size hex. Both of the hex's are tapered. Standard 1/2 inch drive breaker bar fits both sides of it. I removed 100's of those plugs when I ran a service truck. Hitem hard with a 2 lb. hammer first and they come right out.
Great--thank you!
Shouldn't have to remove any drain plugs at this point. Steering seems to be the problem so check for fluid in clutch compartments via the support bolts and then check steering clutch valves/rollers. Curious how much pedal travel you have to apply the brakes? There's a lot of info in the archives on here under D3B/931B brakes. C series is essentially the same as later B series.
Indeed— planning to use the brake band bolt for the quick check. Will regroup on drain bolts once everything else is checked out. I did get the brake adjustment guide specific to my serial number from another super helpful member. In addition to checking the rollers I am going to follow the brake adjustment guide. Part of that is to check the pedal travel. Will be going through all of this on Wednesday and will report back status and outcome accordingly thereafter. Here we go!
There is a much simpler way to adjust the brakes than what the manual says. I learned it from the late Bob/Ont who was a very well respected Cat mechanic on this forum. You can check all the linkage measurements but to adjust the free play you can tighten the brake bands up tight (under seat) then shorten the linkage to the actuator at the back (also under seat) as short as possible and still be able to get the pin in. Then back off the brake bands to get the pedal travel. This guarantee's the free play is at the brake bands and not in the linkage. You don't want the brakes to drag.
Good progress today. Got both brake band bolts out from underneath. Cleaned them up and got them back in properly. Only got one clutch valve off and roller/bearing and cam were fine. Checking other side tomorrow. Wrestled a bit with a few other things to accomplish the above. One question with having so many hydraulic lines disconnected: is there a hydraulic bleed valve for removing air from the hydraulic lines? Or, is there a bleeding procedure in general anywhere to remove air from the hydraulic lines?
Normally you just work it a bit to bleed air. I'm guessing the clutch compartments were dry? After checking the clutch valves and hooking all the lines back up check that the steering valves are fully engaging when pushing on the brake pedals half way down. To adjust the brakes take out the pins from the brake arms that connects at the back under the seat (on the half moon shaped humps). They should have hair pins for easy removal. Your machine may have extended brake adjusting bolts or there are 2 diamond shaped covers under the seat to get at the brake adjuster bolts. Snug the brake bands up. Don't reef on them just snug till they seem to bottom out. Then shorten the linkage rods you took the pins out of as short as possible that you can still install the pins. The pedals shouldn't have much free play. Then back off the brake bands to get the right pedal travel. That will guarantee your free play is in the brake bands and not the linkage.
Clutch compartments were indeed dry. When you say "just work it a bit to bleed air" do you mean fire up the dozer, put it through its paces, and it will automatically purge the air from the system? Or do you mean bleed it like bleeding brakes on a car? For example: loosen it up, pump the brakes until fluid shows (indicating air is out), then tighten it back. Do this at a few spots perhaps? Regarding the brakes: indeed we removed the pins from the arms and shortened the rods where the free travel was removed from the equation where the half moon shaped humps are. Did you mean to say the pedals should NOT have much free play? I will check and ensure pushing half way engaged the cam/roller in the steering valve tomorrow while applying the brake.
Yes, I corrected the typo in my post above. When the brake bands are tightened on the drums and the linkage rods shortened there shouldn't be much free play at the pedals. You need to make sure the linkage for the steering clutches actuates before the brakes. Loosening off the brake bands for enough pedal travel can also help with this adjustment. It may be fine where it's at. If you still don't have much for turning brakes may need to pull top covers and inspect brakes and/or steering clutches. There are test ports for checking steering clutch pressures going to the cylinders in the clutch compartments. They are accessed from the outside above the tracks but try adjusting everything first.
Have a hydraulic tube that popped a weld today. SO, getting that fixed next. One question further though and see the video in the URL below. When I push the brake pedal, the rod on the left (the 2nd rod from left to right) moves a good bit before the right rod in the video (3rd rod left to right) ever even moves. Disregard the audio in the video-- I chopped up the video and just explaining it here. Why would the rod on the left start moving before the rod on the right when pushing the brake only pedal?
Look and see how much each side is moving at the back. Someone may have been messing around with the adjustment in the past. Also make sure all the linkage is free. The center pedal is for brakes only and shouldn't affect the steering clutches at all. If you tightened the brake bands to get the free play for the outer pedals, the center pedal adjustment may need to be adjusted. I have no idea what's been done on your machine in the past. I know on mine one the brake cams in the "hump" was assembled wrong at some point but I was able to compensate by changing the length of the actuating rod. If not I would have had to pull it off and assemble it the correct way.
Thanks again as always Dave! Quite a bit has transpired since last post. Had two hydraulic tubes and a transmission oil hose that all had to be replaced due to leaks. Have everything back together now and have adjusted the brakes where in an initial test they seem to be working properly. While tracking down all the various leaks I did notice something odd: there is oil coming out of the blow-by tube. I have read at one location where that's normal, and then I read somewhere else on the flip side that it's a sign the engine is done and needing to be rebuilt. See the attached image with the location I'm referring to where oil is dripping out. It's not a ton, but it's happening for sure. What is your opinion?
3204's are known for blow-by because they only have 2 ring pistons. The upgrade is 3 ring pistons. Is there oil dripping from the breather tube or just oil residue? Not uncommon to have smoke from the breather tube. Is there any smoke from the exhaust? I would check oil level every 4 hours or so and see if it's going down rapidly.
On your foot operated steering clutch D3 the first three inches of brake pedal travel push a valve pin and diverts 300 PSI of transmission pressure to the short fat clutch cylinder to release the clutch. The remaining pedal movement tightens the brake. Don't set the brakes up to tight so you are dragging the brakes before the steering clutch releases.
Yes, the steering clutches do have to be set/adjusted in addition to the brakes and there is a measurement for clearance between the cams and rollers on the steering clutch valves with the pedals all the way up. .015" rings a bell but can't remember for sure. Don't think it's super critical as long as there is no pressure at all on the rollers with the pedals all the way up. Pushing both pedals half way down machine should coast to a stop. I was referring to the brake adjustment only assuming the steering clutches were set/operating properly. If driving in 2nd gear machine should coast to a stop when quickly shifted to neutral on flat smooth ground and free wheel on a slight to moderate downhill slope. This indicates the brakes aren't dragging. Removing the actuator rod (at the back), tightening the brake bands, shortening the actuator rod and then loosening the brake bands to get the pedal free play guarantee's the free play is at the brakes and not in the linkage. Learned this for Bob/Ont and much simpler than measuring and adjusting every single linkage in the system. It was several years ago I did mine and it's hard to remember every little detail when trying to explain it on a forum. Also hard to know what exactly the problem is with another machine. I had the steering valves rebuilt, steering clutches rebuilt, clutch cylinders rebuilt, new brake bands and installed new sockets/bushings for the ball ends of the steering clutch arms. Lubed the ball ends with dry graphite spray as recommended by the shop that did the steering clutches. Won't attract dirt and debris like grease. It wasn't cheap but I have excellent brakes and figure they will outlast me. I think doing a bunch of band aide repairs costs more in time, money and frustration in the long run. Another poster was looking to fix his brakes but wasn't, or didn't want to, acknowledge that the steering clutches are used in conjunction with the brakes.
Got to use the dozer a good bit today. It looks like oil dripping. I checked oil about every hour and had to add about a quart per hour to top it off, so about a gallon every four hours. Seems like a lot. Thoughts? Also unrelated: I don’t see grease fittings where the dozer arms go up/down, etc. but they were squawking today and definitely need grease. Do I just squeeze it in there how I see best or is there a central grease fitting I al just missing?
A quart an hour is a lot of oil for 65 HP engine. Pins may not use grease fittings or could be in the pins themselves. There was another thread concerning a Cat dozer that didn't use grease fittings on the blade. It was an attempt by Cat to save on daily maintenance. If there are no grease fittings I'd try to remove the pins and if they and the bushings are still in decent shape spray graphite lube on them.
Regarding the oil: does that indicate possible engine failure? Or, does that just mean I need to do a good job staying on top of it? Graphite lube: will do—thanks!
Excess oil consumption could could be piston rings, valves, worn cylinders etc. Check your air filter too as a clogged air filter may contribute to oil consumption. Might be good to do a compression test and blow-by test. Cat may have a recommendation for lubing the pivots.