So I ended up with a older cat 631C scraper. Can someone tell me where to find the ser #. I have never had one if these or driven one until yesterday. I need to get a few things for it. And a book also. Overall it seams to run and work fine, but I do have a few question about it. The brakes don't work(seems like most are that way) so when I push in the red airbrake button, it pops back out after 20 seconds or so. it does pump air and can here boosters when stepping on/off the pedal. normally the reason for bad brakes is wore out shoes or some easier to fix problem? I don't really need to have them working just sort of curios about them. The hold trans pedal, not sure what that does. and the diff lock pedal are sitting on the floor. they are supposed to pop up so they can be pushed down to work? air operated or hyd? I have around 15yrs experience with excavators and big and small dozer, track loaders, trucks and 20yd pull scrapers. None with self propelled scrapers. I have been reading some of the threads about them but I am open to any tips or things not to do while operating from some of you guys that have some experience on these machines. Thanks in advance. Steve
Not real familiar with them, but I do know the trans hold keeps the transmission in the gear it's in while loading or running on a rough haul road. Hopefully you have at least a 7 for push-loading, you're going to need it.
Yair . . . Well said Shimmy1. I never ran them much but pushed a few and I reckoned they were hard loading bastards compared to the Terexes. Cheers.
If you're looking for manuals for it then this is a good place to start. Not cheap, but they are genuine factory manuals - https://servicemanualpro.co Regarding the air side of the braking system, you will need to make sure that the compressor, unloader, brake valves, and air lines are all in perfect condition with no air leaks otherwise you'll be flogging a dead horse from the get go ..... that's even before you think of looking at linings, drums, etc. If worn the compressor can pass oil into the system and if it does you are in big trouble.
Not sure of what S/N prefix you have but a quick check of the 67M prefix shows a very basic air brake system. That said you have to start with the "basics" as Nige said, make sure it builds air, no major leaks, fix the minor ones and maybe then check the adjusters. Looks like a standard "S" cam system so should be easy to trouble shoot if you go step by step and don't just try throwing parts and money at it. I maybe overly picky but feel if brakes were not important why did Cat put them on the machine? I know that is what that big bowl behind you is for, but you might be in an area someday you don't want to be digging into to stop. Without looking in SIS to refresh memory I would say the diff-lock peddle should work up and down to supply air to an air cylinder in the drive axle compartment that moves a sliding clutch back and fourth to lock both front wheels together. At least that is how the, I believe it was a 613, scrapper I worked on a few decades ago was built. The shift fork had come loose and I had to work through an opening in the axle housing to tighten a loose bolt. Well after some research seems it was a 619C with the D340 engine. And SIS does not have anything available for those, says you have to get that info off "Microfilm"!
Got it covered Shimmy, I have had a D8H for years. it already has a reinforced center on the blade. Come on over and give me a push sometime. LOL Thanks for the link Nige. I will check it out. Any idea where the serial data plate is or where the number is stamped?
It's a long time since I worked with a 631C. IIRC the S/N plate should be located either on the LH or RH side of the tractor close to the steps. Remember that there are 2 Serial Numbers, one on the tractor and one on the scraper. You would need to quote the S/N of the front or back end of the machine depending on where on the machine the parts you require are located. Effectively the hitch is the dividing line - forward of the hitch belongs to the tractor, back of the hitch belongs to the scraper.
How's the work down there Farmer? Pretty light up here, I'm thinking of getting in contact with my USFWS guy I used to work with, see if there is anything going on in the wetland business.
Hey Shimmy, I would say its a little slower than last 5 years, but I have enough to keep me busy most of the summer. I don't like to be overbooked anyway. plus I have some of my own projects that I would like to work on also.
Those C series were great scrapers.
Apart from the POS D343 engine that was in them, I'd agree. IMHO the 631D with the 3408 engine in it was a far better scraper. Really when Caterpillar introduced the C series scrapers everything started going downhill because they were the first models equipped with cushion hitches..... :tong:tong
D343 okay, cushion hitches = money in the bank / C-342 engine bit easy to work on, but the hydraulic pumps aren't fun
I think the narrow nose 631c's were 65m xxxx and the wide nose ones were 79p xxxx. If you can hook an air compressor to an air tank drain it really helps chasing the air leaks. It's hard to hear leaks with it running. One thing thats a little old style about the air system is the park brake. I think this is right, that the park brake system airs up first and as it does the brakes apply. So if you haven't gotten the park brake to release, and the brakes aren't dragging, they are way out of adjustment, wore out, or not getting any air to them. After the park brake resevoir builds preasure then the service brake resevoir builds up, then you can release the brakes. Also the park brakes will bleed off- my wife wanted to no who was parking stuff in the woods down the hill from my house, and there my beauty was. It ran away, but didn't get far. If you have the shifter in a higher gear but wan't to delay an upshift the trans hold did that. They are air operated. They are supposed to pop up. The trans hold and diff lock valves on a lot of these have had the air lines unhooked under the floorboard. Access is from the bottom after removing a cover.
Nige, was the 6 cyl, turbocharged, double overhead cam, 4 valve per cylinder motor, fairly advanced for the late 1960's? I here they could be blown up if downshifted wrong causing them to be over revved.
It was far too advanced for its own good if you ask me. Also the DOHC range was rather temperamental, to put it mildly. Back in those days there weren't too many operators who had much mechanical consideration, most were from the "full rack, heaps of black smoke" school of operator training - that is if in fact they'd had any training at all. Having had personal experience of the D343, 346, & 348 I was a lot happier when the 3400 Series appeared on the market.
I was thinking about hooking up an airhose to the scrapers air system. when I have some time. It looks like all the stuff that is air operated is not working and has not been for a long time. My original plan was to make it into a pull scraper. but it seems to work fairly well so maybe I will just use it as it is. It hauls a load of dirt good and the cushion hitch even works. scared the pants off me the first time I moved the lever. ha I do need a bushing for the ram end of one bowl lift cylinders. so I will get that fixed first and see how it goes.
If the differential lock isn't working my advice is to not fix it. I saw too many of them destroy differentials because they were locked and being used on hard surfaces. The lock is really abusive on the differential when turning hard in anything but mud. The contractor I worked for had about 80 or 90 631Cs. He used to have the mechanics weld a block under the pedal so it couldn't be used. Keep that cushion hitch well greased or you may be looking at a line boring job after the bushings are worn out. Most air leaks were usually located from the cushion hitch back. In regards to the 631D, we had 16 or 18 of them once. They were the most gutless pigs I ever pushed on a haul-road or a fill area. The mechanics did everything they could to get more power out of them, it didn't help. How I hated those 631Ds.
I have heard this^^ before, that they were about 150 hp too light. Ok for shorter, flatter hauls, but anything hilly or soft forget it. You would like that. Depending on what kind of terrain you want to work in, and you're going to have to push it anyway, the operator will be much more comfortable in a tractor or wiggle-wagon than that 631 tractor.