The last few years we've encountering a major need for a larger scraper, maybe two of them, first were considering tractors and pull pans, but lately I've been thinking a different direction and maybe a cat 621b model, am also considering terex ts14b's but parts might be an issue later on down the road. First off, never run a cat motor scraper, never been around one, for that matter when I asked, was told nobody locally has run a single engine motor scraper in decades or more now, there are a few, very few cat 627's I think are the number on them, twin engine scrapers and the last I asked the guys who run them I was told, maybe the boss should have bought far better quality machines to start with so they could actually run them instead of fixing them was the jest of that conversation, not even sure they are still in the area anymore. I do have a smaller terex motor scraper, which works great for what we need and bought it for, but not nearly enough machine to actually move a few thousand yards of dirt in a timely manor with, its just far too small and only one at that. Can anyone fill me in as to what they are, years built, what's changed on them over the years and if parts are available yet for them, basically the pro's and cons of them. Also before anyone starts in, these are low used machines, so older and cheaper is what I'm wanting to start with and probably stay with, I'm not into that whole several hundred grand investment kind of thing for this venture, more like that whole 20k or less per machine or for a pair kind of price range, so bear that in mind and also the less anything electronic the better, that whole keep it simple and basic is the whole goal here. There has to be plenty of machines around that still have a lot of life left in them to do what I'm needing to do. Also the whole self loading thing isn't that big of a deal for me, seems all we've been doing is pond cleaning, drainage ditch cleaning and shuffling dirt from point A to B over longer hauls it seems, the last job we did it was a 3/4 mile haul one way, the one before was from one side of a 320 acre farm to the other for a total of 150 scraper loads of dirt is all. Most everything is top loaded using an excavator since we are digging or cleaning something out and it can't be self loaded with any scraper, so that whole push loading to fill to the brim and turn around times are a non issue for the bulk of the work we do involving scrapers or as I'd like to refer to it, "recreational dirt relocating".
For your application an articulated dump truck may be a better option. Something like a Cat D300 or 400 with a tail door.
There are two major issues with any off road haul truck, one is when using in freezing conditions, I'd need two excavators, one to load and other to scrap out the box on the other end, and the second and larger issue is, nobody will run one, and I mean nobody but me would consider running one, its been discussed many times but the answer is always the same, you buy it, you alone can run it, end of discussion. It seems every time this subject comes up, the answer always seems to revolve around the whole concept of a "feeling" you might tip over, a scraper carries the load low to the ground, an articulated haul truck carries it above the wheels and much higher up in the air. There are literally dozens of off road haul trailers in my area, they are very popular and getting more so every year, the box is identical to an off road haul truck, the only difference is the box is pulled for the trailer design and the truck you drive it. With the truck your sitting in the seat and the load is behind you, as it sways, you sway, with a trailer the box sways and the tractors not affected much if at all...........ok to a certain extent I get it, but not really enough to be a huge concern, after all we've never even come close to tipping over a haul trailer, why would we a haul truck? But it gets down to this, I have plenty willing to drive a motor scraper, none to drive an off road haul truck....................so a motor scraper is looking more appealing to me right at the moment. The other issue is this, we've had dump trucks converted to trailer mounts pulled with tractors in the past, they are never home, someone is always wanting to beg borrow or rent them, they all come back broken up or worse yet, they don't come back and I need to waste time going looking for my stuff, then fix it before I can use it and the whole list of issues just keeps growing, with a motor scraper, absolutely nobody but my crew would even consider to sit on it, let alone run it..............so it goes nowhere unless my crew is operating it, servicing it, looking after it and fixing it, which simplifies my life considerably. With any pull scraper, everyone wants to rent it, borrow it, hook their tractor to it, you name it, same goes for the off road haul trailers, they all seem to float around from farm to farm, and it seems I'm always involved in fixing or welding on the same units everywhere I go, just so I can use them and get the job at hand done and I'm beyond tired of that whole concept, basically its not my junk, I didn't rent it, why do I always end up fixing it or being delayed because nobody else can fix their own stuff or stuff they rent or borrow. So I've ruled out anything pulled by any tractor period. So the discussion gets back to this, anyone want to shed light on a Cat motor scrapers, was just told yesterday, Cat has discontinued certain parts involving the air brakes on the 621b's, and even some of the 631E's parts can't be bought anymore, had one guy trying to sell me three of his 631e's because he couldn't get the parts to fix the brakes and without the parts the brakes won't work and whatever job he was going to everything had to work or the machine is kicked off the site, so his three scrapers were banned from the job. I though cat had parts for everything, its always been the sales pitch they give me, but two guys yesterday both told me certain parts are no longer available and without them the air brakes systems can't be fixed...........anyone want to shed some light on this issue??
Come on down to OK. I have a customer with 2 621's I bet he would sell in a heartbeat. 1 ran when parked a few years ago. The other has the heads and piston assemblies removed (but he has all the parts). The engine torn partially down (3408) would need to be removed and rebuilt.
Oh!......I also have a customer that has a 615B (I think it's a B) sitting in his yard right now. It was started and moved about 6 months ago.........just to sit in another area of the yard.
I can't help you much with the 621b's. Years ago I ran one for about a week. I wasn't overly impressed. You said you were worried about parts availability on the TS14. Detroit engines and allison trans should be plenty of parts available. IDK what the final drives are. So that could be an issue. Personally, I would consider a TS14 and replace the 4 cyl front engine with a 6 cyl. By doing that you have the option to self load it also. Unless you are loading going down hill you prob wont get full loads but it will get a decent load most of the time. Just something to consider that shouldn't 'break the bank'.
Bam1968, I just talked to someone a day ago that did just that, replaced the front four cylinder with a 671 and he told me it made all the difference for self loading. His opinion was to buy a 14b because they are 4 wheel drive and a better balanced machine in softer ground both loaded and empty. He also had a 621b and told me to not buy one, his brakes too were not fixable and some of the other parts are no longer available on them as well, he told me the cat was built for more highway type work and the terex was built for more ag type work and working alone and not needing a push cat. I'm not sure the whole push cat thing is a big deal for the bulk of the work we do anyhow, but its something to think about. I asked him about parts and his opinion was terex had far more parts available nationwide due to the Allison's and Detroits in them coupled to the fact the brakes were off the shelf truck parts for the most part. He was wanting to sell his cat, but the brakes were not fixable and it had no cab on it, a must for my next scrapers, I've had enough of moving motor scrapers or anything around in cold weather without a cab on it anymore. I asked him about the whole selling point Cat gives about every part being available for every machine they've ever made, and he laughed and said, yea right, nice sales pitch but the brake systems on cat scrapers were their own design and nobody makes parts for them and cat just quit building certain components which makes the whole brake system obsolete and no aftermarket company has yet to build the parts cat no longer makes. He told me the value of those scrapers has gone down and will plummet even farther till someone starts building parts for them. He said he's called every salvage yard in the US and nobody has those parts left on used machines anywhere. I asked him the difference and he told me to come take a look at both machines they were sitting side by side, terex is truck parts and cat is their own design and I could compare them to see myself. So this next week I'm heading out, about a 800 mile round trip drive to compare the two machines. Vetch, I thought those scrapers had 3406;s in them, not 3408's, do they have cabs on them?? Is the 615 an open bowl or paddle chain machine? Thanks for the info guys.
Unless you have busted the levee and dried down the pond basin over a few years using a pan will be like giving a hog a mud waddie. Will be more stuck than not and often. In the clay soils here the big function equipment users use a excavator at the shallow end of a wet hole get a approach and shove the wet slop out the dam break, use a dozer usually a D8 size, another 8 opposite side to spread the slop so will dry out. After dried down will then come back and finish grade bowl bottom then the slop spread for further use, rebuild dam levee and start the whole process of mudding in all over again. Ditch work would not be so bad but a Pan in a existing Pond Basin is not a great idea.
Both of these 621's have the 3408. ...although I don't have the serial number for either. The other I told you wrong, it is a 613B paddle wheel scraper. I know for sure it needs exhaust system work.
621s came with 3406s 631 had the 3408s. Bob
Thanks vetch, but I'll pass on the whole 3408's completely and the 613 is too small and I do no want a paddle chain machine at all.
I may be remembering the model wrong. Its been 20 years
Sorry to think WE are antiques now.
The older Terex had quite a bit of aftermarket companies making parts. The engine blocks are the same as the truck side. A few accessories might be needed specific to the scraper application. The Allisons are specific to the scrapers, but parts are still available. Brake shoes, S cams, drums, and slack adjusters are specific, but aftermarket alternatives are out there. The key to keeping the green Terex reliable is a clean, moisture free air supply available, and the air leaks for the transmission shifter and actuators under control. The air tanks get rust in them, then the rust gets in valves. If there are too many air leaks, your transmissions aren't always in the same gear and fight each other resulting in short life. If you upsize the engines, but don't keep the following components in good shape, the show won't last long.
I know you asked about 621B's. But, not far from me there are 4 627's for sale. $7000.00 each is the asking price.
The 627's are twin engine models with two 3306's in them or is it two 3406 engines.
I'm not familiar with the 621B brake system. What parts are not available?
I'm not familiar with them either, I've never looked at or seen them, hence the reason why I'm going to look this week at one, where a terex ts14 b is sitting side by side to it, so I can compare and ask questions exactly what parts are no longer available. Two guys who own them, one owns this 621b and another owns three 631e's claim the brakes can't be fixed due to obsolete parts cat no longer makes, both told me cat's air brake system is a cat exclusive design and terex runs a standard truck air brake system. I own a single engine terex and yes that machine has off shelf truck parts for the brakes, the owner of the 14b told me those twin engine machines run the exact same brake system of my single engine unit, but the axles and drive line is larger along with larger tires and wheels to carry the extra dirt and bowl size of the twin engine unit, but the principle was the same, so I'm familiar with terex's system and parts somewhat. The owner of the 621b was trying to explain how cat's system worked and functioned and what was no longer available for parts, but before he got done, I was basically lost, so he told me it was much easier to show me in person the parts that can no longer be bought or replaced...........so I'm going to take him up on the offer and go learn something. Was wondering if anyone else knew about this issue or has had first hand experience in trying to fix a cat scraper's brake system and could shed some light on whats different and what parts can't be bought. Not sure how much faith I to put in two guys opinions whom I don't know personally for the absolute final answer to this, when I asked locally, nobody knew a thing about it, since there are no motor scrapers left in this area they sell parts for or service anymore, so that was a dead end for knowledge on that issue. Guess that means the 627's are no longer around either anymore. Another guy who's owned terex twin engines in the past told me if I bought one, to take the steel air tanks off the machine and put aluminum air tanks on it day one, to help eliminate the rust issues, then put a fitting in the top of the top tank with a valve in it, so at night or during the day, I could pour a bottle of alcohol into the tanks to aid in keeping the air system thawed out and working properly in cold weather, which made sense.
I reread some of the posts and Questionable Wizard said the brakes are terex exclusive, can't argue with that, but when I've needed parts, I take the stuff into the local truck shop and they order what I needed and had them within a couple days or so, not sure where they got them from though, never asked really.
Find a Wagner style air brake alcohol evaporator, put it in the supply line To the tanks not just dump alcohol in them as the liquid not evaporated will draw water and mix with it, think E-gas and those issues.
From a mechanic point of view (same for Cat or Terex equipment), I would have the air tanks cleaned (i.e, take a pic of how your lines connect to the tank, remove tank, wash out, pour in one pound of 1/4" steel ball bearings (source from McMaster Carr) and a gallon of muratic or proprionic acid (Lowe's, Home Depot), plug all holes with steel plugs, place on a one yard cement mixer and inflate a tire inner tube against it to hold it in place. Run mixer for 2-4 hours. Remove plugs carefully pointed away from you wearing PPE. Pour out contents and thoroughly rinse. Dry quickly with a torpedo heater. Pressure test. Take tank to a radiator shop that coats tanks and have the interior coated). Reinstall. Sourcing a tank to match and have all the ports in the right direction will be a challenge. Then I would purchase a AD-9 air drier from a truck parts shop and plumb in. Air line schematics are available. Also install a Stemco automatic drain valve in your wet tank (the first tank after the compressor or air drier). The Stemco valves really work. Alcohol inducers are a Band Aid. There is a reason you don't see OEMs using them. Sure you can get by, but solving the moisture problem is the right way for a solution. You may have a compressor that is generating oil. Air drier and drain valve will get rid of it. Replace your pressure protection valves with new (this is the first valve at a tank port feeding components like air shifter, seat, etc.- it shuts the accessories off if tank pressure drops too low to ensure pressure for brakes). They will have garbage in them. The Sealco ones for truck applications are inexpensive. I usually replace the Rotomax brake chambers on the construction equipment with 36-36 truck maxis. They handle misalignment of the operating rod without binding much better than the Rotomax, and are 25% of the price. Parking brake spring force is similar. If your often top loading the scrapers, switch your spill rack around so it act like a funnel so the excavator has a bigger target. Most are modified this way in NZ as they don't have as many haul trucks. The scrapers do double duty as haul trucks, plus they can spread their loads. If you want more capacity from a Terex top loading, put 12" sideboards on. Just be smart about it. I question whether Cat 621s being single axle drive will motivate adequately when ground conditions get soft or smeary. Here in Ohio, the JD 862s we had many years ago had to be pushed everywhere with a dozer when conditions were soft.
I believe a smart person can solve the Cat brake sourcing problems. We here in the US are spoiled with the manufacturer so close and we need to hone our ability to think outside our comfort zone. I don't know if Cat quit offering the air valves, or hard parts. Somebody with a thorough knowledge of air brake systems can find retrofit valves. Machine shops are available to make hard parts. Shoes or pads can be relined. Calipers can be re-bored. I work for a group of excavating company owners that have very little mechanical knowledge. Their answer to tired equipment is to replace with much newer. Refurbishing is out of their comfort zone and up until now, never employed anyone that demonstrated it can be done. When they rolled equipment out of their inventory, often it was a rolling disaster. They usually have a convenient case of amnesia when discussing condition with the next buyer.
Amazon.com: ALCOHOL EVAPORATOR - FOR HD AIR BRAKE SYSTEMS - A72420 STYLE : Automotive This is the style was speaking of. Ejectors are fine so long as Liquid, once freezes is still frozen.
Thanks for the replies guys, you've been very helpful, never been told or heard of the alcohol evaporator before, that goes in after the air dryer, is there anything that can be mounted before the dryer, I have one truck that the air dryer is mounted too far back and the line from the compressor to the dryer always freezes up, even though there are no low spots in it anywhere. With the service body on the truck, there was only one spot to mount the air dryer, its should be mounted about three feet farther ahead and I think the problem would not exist. I'm hopefully going to find out what parts cat has discontinued the next few days or so and once I actually understand the system, I can then figure out how big a deal it is. Coating the inside of the tanks, what do they coat them with and who would do that, I've asked about gas tanks in the past, and those need to be sent out of state and the cost is prohibitive, never heard of anyone doing it to a steel air tank before. As for the aluminum air tanks and getting the ports just right, we've done several, buy the new air tank, take it to my local machine shop, tell them where the ports need to be and an hour or so later, all the ports are exactly where I want them, they just weld on new ports wherever needed, do the same for stainless or aluminum fuel tanks, even used tanks. For anything pressurized, their air compressor in the shop can test anything far higher pressured than any truck compressor could ever put out, never had an issue yet with one blowing up on me. I personally like the stainless steel tanks better than the aluminum, over time aluminum will corrode really bad, especially with the liquid salt crap they spray on the roads now. Thanks for the link DMILLER this next week I'll order a couple of those units.
They were a fill and forget, usually top off after a week. Air evaporates the juice in the pot where if compressor cycles a great deal may have to look sooner. Look before start and build air or have to drain off.
Thanks for the link, Dave ! I bought one this morning.
Great thing about this forum, many can benefit from any chat on here and learn something along the way and also pass on some tricks of the trade learned over the years.
I've had 2 621B's for 7 years. Former military machines. One came with 300hrs and 500hrs on the other. Both have over 3k hours now. Love them. Made a lot of money for me. As far as brakes I've never used them. Drop that stinger and you'll go through the front glass if the steering wheel doesn't catch you. Been on some very very steep terrain with them. I've loaded them a lot with trackhoe. They just don't go like an articulated dump truck.