Cummins pt injection pump availability

[dbs]

I have an old NTC 350. It had been running fine but now runs only long enough to apparently empty the pump, about a minute. Then will not restart. If you fill the pump with fuel it will run again for a minute or less. The dealer says the seals in the pump are likely bad and wants 1K to rebuild it. I've seen rebuilt ones on eBay for 300 but even though the pumps look identical to mine the numbers on the pump are different. Anyone have a source to cross reference these numbers to figure out if a particular pump fits a particular engine? Thanks, DBS

 

[powerjoke]

Don't you have a fuel shop somewhere close to send it ?

As far as the eBay pump goes, my thoughts are hell I would try it, it's only 300 that's not even a tank of fuel anymore

Pj

 

[lantraxco]

I assume you've tried turning in the manual screw on the shutoff solenoid?

Checked all the lines and filters back to the tank to be sure it can't be sucking air somewhere along the way?

Disconnect the suction line, plumb on a length of fuel hose and stick it in a fuel can with clean diesel in it just to be sure it's a pump issue? With the return line going back to the original fuel tank it won't run for long this way, but if it sucks all the fuel up that should indicate that there's an air leak in the suction side somewhere. Just a thought.

As I recall the pumps are supposed to be set to the CPL so the engine gets the right amount of fuel. Some had an aneroid which sensed turbo boost and adjusted fuel pressure I think. Whoever's selling pumps give them your CPL and they should be able to sell you the right pump. I like to deal locally as Powerjoke suggested, usually in the yellow pages under "Diesel fuel injection".

Good luck!

 

[powerjoke]

Put an air chuck in the fuel tank lol,

Most of the times when the pt pump leaks it will have fuel running out of the weep hole on the section between the pump and the accessory drive on the engine,

I bet you have fuel algae or like lantraxco said something like a plugged line etc.

If ur gonna give the pump to the scrap pile send it to me ill pay shipping plus and give you a few bucks for it, I bet it's still good ;-)

Pj

 

[lantraxco]

Put an air chuck in the fuel tank lol,

Most of the times when the pt pump leaks it will have fuel running out of the weep hole on the section between the pump and the accessory drive on the engine,

I bet you have fuel algae or like lantraxco said something like a plugged line etc.

If ur gonna give the pump to the scrap pile send it to me ill pay shipping plus and give you a few bucks for it, I bet it's still good ;-)

Pj

Also a good idea, IF you don't get carried away! I saw a "mechanic" do this one day and blow the clear bowl off the water separator on a machine. Lucky we didn't burn the shop down, LOL.

 

[td25c]

Still having trouble with the NTC 350 dbs? Double check the "Symptom's list" on page 32 through 35 in your Cummins Troubleshooting and repair manual again before pulling the pump 1,000 sounds abit steep on a cummins pump rebuild.I've sent all my cummins pumps & injectors to Interstate Fuel Injection Service in Seymour IN.Allways had good service from them at a reasonable price.Funny thing is I have never been to there shop in person,I allways just call them & tell them what I need done with a pump then box it up and ups it to them.I guess you could do the same .Might give them a call ask for jeff.Good luck dbs. www.bloglines.com/company/8457055/Interstate.Fuel.Injection.Service.812-523-3308

 

[dbs]

Thanks for all the good advice from everyone. I did what Lantraxco suggested and hooked a line directly from the pump to a fuel can. When the can is placed below the pump level the fuel level in the pump seems to slowly go down and I can hear a very faint hissing sound at the pump but I can't tell exactly where on the pump it is coming from. When I raise the can above the pump level fuel will pour out of the fill plug hole on top of the pump with the plug out, is this normal? With the can raised above the pump level the engine runs perfectly. When the can is lowered below pump level the engine soon quits. Any more ideas? Thanks, DBS

 

[lantraxco]

Making progress. I am not a Cummins expert by any means, just throwing some suggestions out there.

When you say that with the can lifted above the pump, which I think is causing a siphon effect, and fuel comes out of the priming plug hole, is this true with the engine off? If it's flowing pretty freely without the pump turning then it sounds like the gear pump may be pretty worn.

I'm not sure but I'm guessing the pump housing is open to the suction side so you need that priming plug screwed in to make a valid test?

I'm thinking it's sucking air somewhere on the pump and there's only so many possibilities. If it's not leaking fuel anywhere obvious then that leaves the drive shaft seal, throttle shaft seal, if it has one the tach drive seal, and if it has the AFC where a line from the intake manifold attaches you may have a hole in the diaphragm. Try removing that line and plugging the port, see if that makes a difference. If it has a tach cable take that off and find a way to cap the drive with a piece of rubber or like that with a hose clamp maybe? Usually if a gasket or throttle shaft seal is leaking you'll see fuel coming out somewhere, but seals do funny stuff sometimes. If it's a drive shaft seal, you might be getting some fuel in the oil pan also. Gotta be a pretty good leak if it won't suck fuel from a can on a short hose. Good luck.

 

[dbs]

Making progress. I am not a Cummins expert by any means, just throwing some suggestions out there.

When you say that with the can lifted above the pump, which I think is causing a siphon effect, and fuel comes out of the priming plug hole, is this true with the engine off? If it's flowing pretty freely without the pump turning then it sounds like the gear pump may be pretty worn.

I'm not sure but I'm guessing the pump housing is open to the suction side so you need that priming plug screwed in to make a valid test?

I'm thinking it's sucking air somewhere on the pump and there's only so many possibilities. If it's not leaking fuel anywhere obvious then that leaves the drive shaft seal, throttle shaft seal, if it has one the tach drive seal, and if it has the AFC where a line from the intake manifold attaches you may have a hole in the diaphragm. Try removing that line and plugging the port, see if that makes a difference. If it has a tach cable take that off and find a way to cap the drive with a piece of rubber or like that with a hose clamp maybe? Usually if a gasket or throttle shaft seal is leaking you'll see fuel coming out somewhere, but seals do funny stuff sometimes. If it's a drive shaft seal, you might be getting some fuel in the oil pan also. Gotta be a pretty good leak if it won't suck fuel from a can on a short hose. Good luck.

Yes, the engine is off when the fuel comes out the priming plug hole with the plug removed and the fuel can above the level of the pump. I'm thinking of purchasing a smoke stick(used in the insulation business to find air leaks, drafts, in your home), to try and find where on the pump a slight hissing, sucking sound is coming from to find this air leak, thanks again, DBS

 

[mitch504]

What if you put an electric pump inline on the suction side of the pump? That should show you where your leak is.

I know that if the machine has the fuel tank mounted above the engine, you need a float tank to keep fuel from running through the pump and dripping through the injectors, so it must be normal for fuel to flow through the pump. I just don't know quite how much.:beatsme

 

[thepumpguysc]

IF buying from ebay..MAKE SURE the CPL#'s match. I get that ALOT! Customer will bring in a PT pump and the 1ST QUESTION I ASK, "is this the pump off the engine?" Customer replies, "NO but they look the same"..
"I wanted to get THIS ONE rebuilt before I take the other one off"..I reply, "GONNA NEED the #'s off the ORIGINAL PUMP TAG to MAKE SURE we match it to your engine"..
CPL stands for "Controlled Parts List".. It tells the mechanic EXACTLY what "the engine/pump is SUPPOSED to have in it"..
$1000.00 is WAY out of line..$400.00 is norm..
Don't get me wrong, its very easy to take "this" and make it "that" but there are normally parts changes that need to be made that drive up the cost, springs, buttons, shims and lets not forget the proper calibration.
CPL#"s are everything. BUT you don't want to spend 300.00[ebay] + shipping and have to get it matched to your CPL for another 200.00 when you could have taken it to a reputable fuel shop and had it done for 400.00..
A PT pump is nothing more than an "oversized" gear pump..so if your not drawing fuel, there's either a leak, a blockage or the pump has failed.

 

[dbs]

IF buying from ebay..MAKE SURE the CPL#'s match. I get that ALOT! Customer will bring in a PT pump and the 1ST QUESTION I ASK, "is this the pump off the engine?" Customer replies, "NO but they look the same"..
"I wanted to get THIS ONE rebuilt before I take the other one off"..I reply, "GONNA NEED the #'s off the ORIGINAL PUMP TAG to MAKE SURE we match it to your engine"..
CPL stands for "Controlled Parts List".. It tells the mechanic EXACTLY what "the engine/pump is SUPPOSED to have in it"..
$1000.00 is WAY out of line..$400.00 is norm..
Don't get me wrong, its very easy to take "this" and make it "that" but there are normally parts changes that need to be made that drive up the cost, springs, buttons, shims and lets not forget the proper calibration.
CPL#"s are everything. BUT you don't want to spend 300.00[ebay] + shipping and have to get it matched to your CPL for another 200.00 when you could have taken it to a reputable fuel shop and had it done for 400.00..
A PT pump is nothing more than an "oversized" gear pump..so if your not drawing fuel, there's either a leak, a blockage or the pump has failed.

Thanks for the great info. Do the numbers on the pump give you the CPL? I know my CPL but the seller on EBay does not know the CPL of the engine the pump came off of. Is there any other way to match the numbers on the pump to my CPL? Thanks again, DBS

 

[thepumpguysc]

BIG "RED FLAG"!!! YES the tag on the pump does give the CPL OR "SHOULD"!!
IF the seller doesn't know what he's selling..THATS A BIG RED FLAG..
Buyer BEWARE..A can of CUMMINS BEIGE is called, "AN OVERHAUL IN A CAN"..costs about $3.00
I have 1 nitemare story of buying a "rebuilt" pump off ebay..Lets just say for time sake..it wasn't..and its a damn good thing I just needed some parts off of it to make my customers pump complete..[factory didn't have them and no production date was in the near future] and I WASNT the end user and had the experience to sift thru the mess..
Had I been the end user and bolted it up to my equipment..it would have NEVER STARTED..

 

[dbs]

What if you put an electric pump inline on the suction side of the pump? That should show you where your leak is.

I know that if the machine has the fuel tank mounted above the engine, you need a float tank to keep fuel from running through the pump and dripping through the injectors, so it must be normal for fuel to flow through the pump. I just don't know quite how much.:beatsme

Thanks for the suggestion. Instead of the electric pump in line I just put a hose directly from the pump to a 5 gallon fuel can and raised it about a foot above the pump and sure enough I found the leak. The tachometer hookup. I guess I am looking at a new/rebuilt pump. Thanks again, DBS

 

[dbs]

BIG "RED FLAG"!!! YES the tag on the pump does give the CPL OR "SHOULD"!!
IF the seller doesn't know what he's selling..THATS A BIG RED FLAG..
Buyer BEWARE..A can of CUMMINS BEIGE is called, "AN OVERHAUL IN A CAN"..costs about $3.00
I have 1 nitemare story of buying a "rebuilt" pump off ebay..Lets just say for time sake..it wasn't..and its a damn good thing I just needed some parts off of it to make my customers pump complete..[factory didn't have them and no production date was in the near future] and I WASNT the end user and had the experience to sift thru the mess..
Had I been the end user and bolted it up to my equipment..it would have NEVER STARTED..

Thanks forthe warning. You may have saved me a few hundred bucks and possibly other members. DBS

 

[lantraxco]

Thanks for the suggestion. Instead of the electric pump in line I just put a hose directly from the pump to a 5 gallon fuel can and raised it about a foot above the pump and sure enough I found the leak. The tachometer hookup. I guess I am looking at a new/rebuilt pump. Thanks again, DBS

Or reseal the tach drive, or replace the tach drive, or if you don't care about the tach, just cap it, with a rubber disc in the cap. The tach drive is supposed to be hard to get out, your mileage may vary. Here's a pic I found:


And some part numbers from the same web page, no guarantees:
1 104087 shaft 1 70723 bushing 2 154088 seal

Hope that helps.....

 

[Markat425]

For what it's worth the truck dbs has is a 1974, same year as mine. Unless the engine has been updated it won't have a CPL because Cummins didn't use them back then. The injection pump will have some code numbers on it though. Those numbers along with the info from the engine tag (on the acc. drive) will tell a pump shop what the engine was originally. Hopefully the engine tag is still there. As a last resort the engine serial number will give the shop a cross reference.

Another way to find a air suckin' seal on a pump is to spray ether on the pump with the truck running. If it speeds up, you gotta sucking seal.

 

[dbs]

For what it's worth the truck dbs has is a 1974, same year as mine. Unless the engine has been updated it won't have a CPL because Cummins didn't use them back then. The injection pump will have some code numbers on it though. Those numbers along with the info from the engine tag (on the acc. drive) will tell a pump shop what the engine was originally. Hopefully the engine tag is still there. As a last resort the engine serial number will give the shop a cross reference.

Another way to find a air suckin' seal on a pump is to spray ether on the pump with the truck running. If it speeds up, you gotta sucking seal.

Thanks for the additional info. The Cummins dealers showed me the computer printout of the engine info and no cpl was listed however the dealer told me it was 160. Also the dealer said that fixing the seal in the tach drive would not solve an air leak problem there. The dealer also has come down in their price to rebuild it to 600 so I think I'll go for that. They have a well known mechanic who has been rebuilding them for nearly 40 years with likely all the parts on site. The other shop in town couldn't give me a very firm estimate and said the would likely send it out of town. The cummins dealer here other than being expensive is very good and customer friendly. Thanks again, DBS

 

[Truck Shop]

Standard price to rebuild a PT pump now, 11 years later--------$800 to $900 -just a reseal
and check calibration is $500--Rebuilt Cummins top stops {OEM} $200-aftermarket $100.