I can really use some help and some opinions !!! I'v got an 72 Case 450 Crawler Loader that's in great shape. Bought it from a man down in west Virginia at a hell of a deal, shes a really nice little dozer, I use her around the farm and and work cutting timber. She has had a brand new undercarriage and paint job right before i bought her and everything else is in perfect working order, took me awhile to find one this nice. My problem is I have recently began to loose power, BIG TIME, to the point she doesn't even want to turn (spin) the tracks over in low gear when against a stump or full blade. I'v replaced the fuel filters, flushed fuel lines and cleaned the little screen at the inlet of the pump. She revs in neutral just fine but when I go to cut she bogs and wont turn her tracks, even heading up hill she slows and bogs to the point that I'm worried of stalling her ( no brakes ). I'm new too dozers but not to turning a wrench but i need some help or input from anyone with experience with case crawlers... any input or help is much appreciated in advance !! P.s. She does smoke a little, even at idle.. I'm thinking injectors ?!?
How do you stop the engine, with the switch or a kill cable? Have seen cables stick partially and restrict travel at injection pump, causing the same problem.
Shes a kill cable but i thought of that earlier on when i first noticed her power loss, checked it and even replaced it because it would stick a little now and then, just put in a new plunger style throttle cable i had laying around. Do these 450's have a screen or filter at the top of the sediment bowl ?!? I flushed lines when i changed primary and final filters and I had what i beleaved adequate flow to the top of the final bleed off screw, full and steady streem with half a tank on level ground. I replaced air filter and checked inlet pipes as well, the black smoke at idle and full throttle led me to believe i had an reduction of air but no luck with an increase.
Can anyone tell me the cheapest route as to replacing injectors ?!? Aftermarket or OEM ?!? I was told these pumps are pretty much a hit or miss when it comes to one failing, either they're shot or there good ? is it possible my pump has lost its pressure ? and is it possible to turn the pressure up? From what i understand there is no real way to rebuild these pencil type injectors, but can a man benefit from cleaning them and re adjusting pressure settings or am i better off to bite the bullet and pay the $127.00 apeace ?!? A place called littles farm supply near home hear quoted me at $170.00 each, i felt this was high priced ?!? Thanks again to anyone that is willing to help me with any info, i will return the favor as best as i can in the future.
Could be the weight retainer comeing apart in the pump Pull the return fitting out of the top of the pump (return line with the little glassball) and see if it is stopped up.
It's a lot easier to tee a pressure gauge into the inlet to the injection pump and see what that tells you than to start replacing parts. With the black smoke at idle and full throttle are you thinking the injectors are leaking? How does the engine sound at high idle and under load? any change from when it had normal power? I'd still stick with the simple test first, see if the fuel pressure holds up under load and then look at the pump or injectors.
I took today and tomorrow off to get the problem resolved along with this weekend, first thing in the a.m. I will check the return line fitting at the pump, never thought of it, good advice, thanks. And i will cross the river and pick up a fuel pressure gauge, will one that will register up to 3000 psi do the job ? I believe it should hit somewhere in the 2,600 psi range?!? Correct me if im wrong... Will look it up in a sec, have service manual in pdf format on my laptop. And delmer, she sounds the same at high idle when not under load, even has decent response( will rev up quick ) but as soon as i get her under load she bogs, starts out decent but after a secound or two of cutting she starts slowing, bogging and then almost comes to a complete stop and strives to turn the tracks on loose soil...
Delmer, i believe i miss understood you. Are you saying check the supply pressure to the pump from idle to under load ? or see if return line builds more pressure from idle to under load ? Thanks again guys, I appreciate your time.
NO, you're looking for a low pressure gauge (15PSI if you can find one) or combination pressure vacuum (30psi-30inches mercury/vacuum). If there's a transfer pump then you're looking at less than 10psi, if it's gravity fed then you don't want to see any vacuum. If it's gravity fed you could use clear tubing and a standpipe to see how much it sucks. If you have the manual you'll have the fuel pressure spec, but you're looking to see how much it drops under load and if the engine sound/power corresponds to the fuel pressure reading.
Yes, the supply pressure as close to the inlet to the pump as you can. It should be 4PSI (as an example, guess) at slow idle, pretty much the same at fast idle, and pretty much the same at full load. If the pressure changes noticeably then pay attention if to how the engine sounds and how much power it has as the pressure drops and recovers.
Can't really see it being injectors, they'd go one at a time causing a miss. How is the fuel flow from the tank to the filters and pump? At this point I'd be making sure you don't have a partial blockage at the fuel pickup or in one of the fuel lines. Is there a drain in the bottom of the tank? Open it to see what comes out.
Gottcha, I will check first thing in the a.m. and check everything else i can come up with and get back with you either way, thanks for the info..
Wilko, I thought I had good flow from tank to filters, this was just by observation tho, not a pressure gauge. I changed both filters, empty'd the sediment bowl and blew fuel lines out from tank to filters.. I had heavy steady flow at the bleeder valve on final filter with half a tank on level ground when i bled system out to start again, i figured it was sufficient flow but i may be wrong, im gonna hook up a low pressure gauge in the mourning and check properly. I didnt unscrew the sediment bowl valve from the bottom of the tank tho, i didnt think i had a screen on the top of it, if so it must be pretty small ?!? But i will do so as well come a.m...
Well i checked screen in bowl and it was decent, a little dirty but not to where I would think it would restrict fuel flow. It is gravity fed tho, Checked with low pressure gauge and it was hard to register but it never changed from low idle to full throttle to under load, but didnt seem like much.. Can a man put a 12 vlt. diesel fuel supply pump on it at the bottom of the tank ? Like the little green universal pumps they sell at o'rieleys, i believe they will build about 7 psi, would this be sufficient ?!? I figured it would eliminate any fuel loss now and maybe future ? Any other guesses ? And as far as the return line at the outlet of pump, I dont understand how this would cause me to loose pressure to injectors or cause more leak off than normal? any more suggestions ?
You don't have to understand it, just check the fitting for little black pieces plugging it up. You could use an electric inline pump and 7 psi would be more than enough, but the system should work fine the way it was built. If there isn't a separate transfer pump then there is a low pressure pump as part of the injection pump that could be failing. Did you have a vacuum gauge? I can't see how you would get any reading with a gravity feed. You could try a clear tubing "standpipe" that you could observe from the seat as you're operating.
I was only able to register literally like 2 pounds because of it being gravity fed, no vacuum gauge but i figured i would loose my two pounds if supply was not enough.. I actually forgot to check the return line fitting ( been alot going on ) but will do first thing, black pieces ? Deteriorated gasket maybe ? And from what my manual says you are correct, it has a low pressure suction pump as part of the injection pump itself. The reading I had on low pressure gauge may have been wrong all together. I will also try the standpipe first thing as well.
Delmer ! I finally got back around to working on my old girl.. I pulled the return line T fitting at the top of the pump and sure enough there was two small black plastic peaces lodged in the fitting, i dont think enough to completely block flow but deffinetly enough to restrict it a little... So what does this mean ? where would the peaces come from? the pump ?
I only know this from Pumpguy and other's posts here. Apparently there's a flex ring/weight retainer in some pumps that comes apart predictably and plugs up the return fitting, you can clean the fitting out, but if the ring comes apart completely your engine will run away, most likely destroying far more than the pump. So you might as well replace the parts or take it/send it to somebody who will go through it. Wouldn't hurt to post a pic of the pieces that you got out of the fitting and the id plate on the pump.
When the return stops up the pump goes to o fuel to save it self from rupturing. Pull the pump off and get it fixed.
Will do... Thanks guys, appreciate everyone's help!! Now to find a re-builder..