Case 450 with Fuel Problems

[mr hurt]

I recently bought a 1976 Case 450 dozer, got it home and it ran about 1/2 hour and now the motor dies frequently. i can restart it right away, but dies again if i move throttle to much. if i manage to rev it up all the way and let off real fast the motor dies.
i have changed fuel filters, check sediment bowl and cleaned fuel screen in back of fuel pump. and changed to new air filter also.

i need some help, i have reached the end of my diesel knowledge. didn't take long to get there.

any help or ideas would be appreciated.

 

[grandpa rich]

We had a similar problem on a jd tractor a few years ago. The dealer kept insisting that there was a blockage in the fuel line or the tank. We kept blowing the line back and went so far as to drill a hole in the fuel tank itself to get better look inside. It was perfect so I called a different dealer and he told me the problem was in the hand pump or primer pump. It was we changed it and it's been running ever since. If your tractor has one I'd sure check it before going into the fuel pump. Also on the older tractors if you don't know where they have been setting check the air cleaner from the intake to the filter for a mouse nest. I seen a tractor so plugged it started sucking oil out of the crankcase. Good Luck!

 

[willie59]

The 450 dozers that had the 188 and 207 diesel engines were a gravity feed fuel system from tank. Glass strainer bowl on bottom of tank has an inlet screen on the pipe nipple that threads into tank that could be clogged. Could be a rag or piece of debris that is blocking inlet screen. The fuel line connections used rubber sleeve seals, one of those could be sucking air. Canister type filter/s could have a bad seal ring sucking air.

 

[alrman]

I'm going with the ol' plastic drive ring in the injector pump, breaking up & clogging the outlet valve trick .....

Some models have a fitting with a glass ball in it - at the marked location.
This has a description of a 'tee fitting', so may not have ball in it, but still worth a look - if it is same setup as yours.....
Pay to check if the whole return line is clear from pump to tank.

If there is bits of small black material - the pump needs an overhaul.

 

[mr hurt]

ok i will check the tee fitting to look for anything out of the ordinary.

and i will check the return line.

it just buffalo's me, never had a diesel act line this.

 

[mr hurt]

i havent had a chance to take fuel lines off but i stopped by garage to take this picture and tried to back dozer outside for a sunlight picture.

but now it will not even stay running long enough to back out of garage.

problem seems to be getting worse.

 

[alrman]

That picture seems to show the fitting/valve between the pump & the tee. The little glass ball must move freely in the fitting - clear it with compressed air.

 

[mr hurt]

Ok,

I want to say thank you i took the fitting out and you can see from the pictures it was stopped up. first picture before cleaning, second picture after cleaning, the dozer runs much better now.

but you said if it had black stuff in the check ball fuel pump is going bad, can you explain further? is the black stuff the seals coming apart?

Thanks Again
David

 

[alrman]

but you said if it had black stuff in the check ball fuel pump is going bad, can you explain further? is the black stuff the seals coming apart?

As you continue to run the engine you will find it will block the fitting again - sometimes it only takes minutes.
The contamination comes from a plastic ring that is used in the pump internals. Over time the fuel / heat takes it's toll & it breaks up into tiny pieces.
It must be repaired by an overhaul - as with most things mechanical - when it has a problem, it will cause more wear & damage the longer you leave it......

BTW - that is a terrible pic - putting glasses on did not help

 

[thepumpguysc]

Thats pretty severe..I dont know if you guys know it or not but the pump manuf. has released a permanent fix for the flex-ring problem.. its an enclosed drive ring called an "EID" weight retainer. NO MORE pulling the pump every couple of years for a failed flex-ring!!
runs about $50.00. Most pump shops wont tell you about it unless asked because they want the return business, if you know what I mean.
Mr. Hurt> if you absolutly need your machine before you get the pump repaired, there is a "temporary patch" that can be preformed. Mail me direct for simple instructions.

 

[mr hurt]

sorry about the picture, cell phone picture.

 

[mr hurt]

ok tell me more about this fix for the pump.

i have time for my dozer, i am going to south korea for a while then when i get back it will still be mud season in virginia.

i have buried dozers up and over tracks buy trying to work to early in the year.

so what is involved in a pump rebuild, can i scribe the housing to mark its position and take it to get rebuilt? is it just that easy?

 

[thepumpguysc]

seeing you didnt send me a PM I'll send you 1.

 

[mr hurt]

is the pump disassembly and reassembly as staraight forward as it seems?

there are three bolts hold ing the pump on. I should scribe or mark the pump housing in some way before taking off the engine. do this before taking three bolts out.

there is two seals that face away from each other that goes on the shaft that stays with the engine, is there any special installation for these seals?

then for pump installation i have to line the dots up on the end of the shaft with the dot inside the pump to get timing correct.

any tips for getting the pump over the new seals i pump on the shaft??

after that i bolt the pump back on lining up with the mark made from earlier.


if i am missing some important steps please let me know. thanks

 

[alrman]

is the pump disassembly and reassembly as staraight forward as it seems?

1) - there are three bolts hold ing the pump on. I should scribe or mark the pump housing in some way before taking off the engine. do this before taking three bolts out.

2) - there is two seals that face away from each other that goes on the shaft that stays with the engine, is there any special installation for these seals?

3) - then for pump installation i have to line the dots up on the end of the shaft with the dot inside the pump to get timing correct.

4) - any tips for getting the pump over the new seals i pump on the shaft??

5) - after that i bolt the pump back on lining up with the mark made from earlier.

1) You will need a 9/16" startermotor/halfmoon spanner for the rear mounting nut & depending on the spanner make you will need to grind the ring on one half as it will not have enough clearance between spanner & pump housing.
re scribing - ideally you need to check timing, but if you remove the thin rectangular cover held on with 2 screws on the side of the pump, you will see timing markers. Before you remove the pump, rotate the engine till these line up; remove the pump; do not rotate engine; when installing - align the marks.

2) The seals just stretch over the end of the shaft

3) Yes line up the 2 dots on the end of the shaft - if you don't the timing marks metioned in #1 will not align ( 180 deg out)

4) There is a tool. But it can be done easliy using fingers. Lube the seals (I use Vasolene) & gently move the pump onto the first seal, tucking in the lip with your fingers.
Often as the pump is about halfway onto the first seal - withdraw the pump a little, & then back on - it seems to help....

5) align the marks in #1 & "Bob's your Uncle"

** Do not remove the driveshaft with the pump - just undo the three mounting nuts & slide the pump off the shaft.**
I usually remove the fuel filters & housing & the exhaust manifold to allow easy access to the injector lines - some guys leave the manifold on - please yourself.

 

[mr hurt]

ohh didnt even think about bolt in back.

thanks will they to post better pictures of disassembly and installation in a couple weeks when i come back home.

 

[thepumpguysc]

keep the throttle tied back to the full throttle position..

 

[mr hurt]

ok, explain further. tied back while taking off shaft or just tied back the whole time off?

 

[thepumpguysc]

While taking off and putting back on, otherwise the flyweights inside the pump may become dislodged and all hell will beak loose when you start your engine.

 

[mr hurt]

ok will do, and i looked in the case manual under "all hell breaks loose" and didn't find anything. But it sounds expensive.

thanks for the help.