Alt source of bleed line leak D6-9U

[yellercat]

Looking to isolate the source of a nagging leak from the bleeder line on the D6-9U. This is the line that runs down the side of the fuel filter 'tower'. My late serial unit has an additional line that joins into the line that starts at the top 'knob' bleeder on the filter housing. Anyway, I have determined that it is not originating from the top bleeder valve.

Can anyone tell me what the exact source would be for the other line that joins the one from the top of the housing; and what the particular problem might be for fuel escaping past that source?

The 'leak' is substantial enough to prevent operating the unit for any more than a minute or so, (especially with these diesel prices ). More than a drip and not quite a steady stream. I have recently cleaned the housing out and 'rebuilt' the fuel transfer pump. Also replaced the seals between the injector pump and f.f. housing.

Hope someone has run into this problem before and can direct me to a solution! thanks

yellerc@

[SJ]

Does that second line screw into the transfer pump and if so screw it out and start it and see if you get the leak there.I think normally the drain from the top cover of the filter base was connected to that pump drain and drained down as one line.That would be the easier thing to do is even take both connections loose and then see where the leak is.If it is that lower conn. leaking then the pump seals are gone and maybe needs a rebuild wth the gears and shaft and seals.The other line that runs from under the injection housing gets rid of any fuel getting by the injection pumps in the top portion of the housing.

[yellercat]

SJ - Its definately the lower line, so it looks like the pump will need a rebuild. Guess I muffed something up in it, cause just went thru the transfer pump!
Since my books at the country , could you give me the seal #s for very late model 29187 ?
Could it be seals on the 'installation' instead of the actual 'assembly' pump seals? In other words, could it have been something in the way that it went back on? Remembering that there are some o rings on the bolts...
thanks

[SJ]

The pump has the two tapered seals and are 1F5471 and there is a gasket that drops down in the body before you install the lower seal in the body and is just a flat neoprene thin flat gasket the ones that they used when I was working yet and it is 3H7054 and I,m sure they still are the same and are the same diameter as the seals.The only "O" ring used in the mounting is a 7B305 that seals around the fuel tube on the top of the body where the lower tapered seal is in.

[yellercat]

SJ-

thanks for the numbers, looks like she has to come off and get checked out. Sure does suprise me that it is leaking with the 'new' parts that I put in. Again, I must have done something wrong to allow it to leak like it is. (Didn't leak before my improvement! ).
BTW, what about if something like leaving the pressure relief spring out is the case?? Would that account for the leak???
yellerc@

[edb]

Hi yellercat,
the scan below is of the tooling I used to use at the Dealer to fit the packing type seals. As stated in the text you use the installer on the shaft to fit the packings without cutting bits out of them on the sharp corner of the shaft at the gear shoulder, and the Tamper tool to finally seat and pack the packing around the shaft and bodies. If the tamping is not carried out the spring load is not enough to distort the packings to seal around the shaft and in the bodies.
I am sure this is the source of your troubles.
Hope this helps.
Cheers,
Eddie B.

[yellercat]

edb -

that certainly is some relief at this point! In my review of the manuals, this did not come to light. I will pull the transfer pump and have a looksee with your scan at hand. Betting that you are spot on with your analysis of the problem, many thanks for pointing me in the right direction!
Will let you know how she comes out.
yellerc@

Is there any amount of run time that will 'seal' this leak ??

[edb]

Hi yellercat,
from my experience the seal packings will not bed-in. I can only conclude that there was a change in the texture of the packing material because as you point out none of the early manuals mention the need for tamping home the packing. The Fabricated Service Tool article did not appear until 9-65, so I do not know what was done before that time. It was about this time I was training as an Apprentice in the Dealer Fuel Pump Room and I have always known to do this in my time as we had the tooling. Apprentices got to spend time in all workshop areas, but you had to earn the rite to get into this area.
Cheers,
Eddie B.

[yellercat]

edb-
Congrats on getting in the pump shop! Things are sweeter when earned by hard work.
There was a difference in the material as you have mentioned. When I removed it, it was more sticky and pliable that the new material, which was a fibrous like material, probably the kind needing the packing in. Easy fix would be to change to the older material, but likely it is NA. (As so many other things) Parts dept will say 'superceded' and think nothing of it. But it does present an obstacle. Going to pull my pump off and have another looksee. Perhaps I can pack it sufficiently with makeshift tools. Otherwise, I will call the Cat shop and see if they are familiar with the process that you recommend. That will likely get me fixed up.
Really appreciate you sharing your insight into this matter, as I have not come across or heard of it before, and surely would have scratched a hole in my head by now!
thanks edb

[SJ]

I ran the engine rebuilding shop for the local Cat dealer retiring the end of 1991 and we never had or saw a tool like that but I,m not saying there wasn,t one.I probably rebuilt 100s of them on engines with a pump seal setup like that because they all used that style seal till they made the big change and I never saw or had one leak but I made sure they were in place tight as possible.Over the years I made some tools to make a job easier or work better and they sure came in handy and saved time too.We had a home made clamp to make it easier to assemble the end drive gear after the seals were installed and it was just one of the steel rings from a master pin from a track and it was just the right hole size to slip down over the smaller diameter of the seat assem. that has the outer seal next to the drive gear and it had two studs welded on it and placed correctly to go down through the mounting holes for the pump and you dropped it down the holes and pulled the seat down with nuts on the lower end and it worked so easy then to get the outer gear on and draw it down over the key and shaft. Even one could be made from a flat piece of iron but the big center hole needs to be bored the right size and the bolt holes spaced right.