Lift Pump Rebuild...

[JEBalles]

Since diesel was leaking into the crankcase oil, I decided to rebuild my lift pump as that seems to be the most likely culprit. I'm working on getting all the bolts and such out. The female-female output port is giving me trouble--a socket won't fit around it. The big bolt on the back is being a pain, but I'm going to get a 30mm socket before I give up on that. Has anyone done this before? I ordered the kit from here...

[Biodiesel300TD]

I didn't think the 123 liftpumps were rebuildable.

[Diesel911]

I took mine apart to change the little O-ring

On the Fule Supply/Lift Pump plastic Out Put Line you could just leave it on the Pump and remove the it up by the Filter by removing the Banjo Bolt and deal with it after the Pump is off of the Fuel Injecting Pump.

However I removed mine with a Crows Foot Wrench on a 3/8 Extension and 3/8 Wratchet.
I do not recall what size I used.

Below is a pic of a Crows Foot and two 30mm Sockets. The Big Nut on the Pump is so thin that I needed to grind the one on the right flat so that it would be able to grab it. Do not close the Vice on the Mounting Flange.

Also if you put the Pump in a vice unless you have some Copper or Aluminum Jaw Pads it will slip out and the Mounting Flange is thin and it cracks easily.

I had trouble removing the lower Rear 10mm nut. What I needed was a stubby 10mm Combination wrench.

[JEBalles]

Alright, I have the ground down 30mm, should I bolt it back on to take it off, or should I be afraid of breaking the studs?

[Beagle]

Originally Posted by JEBalles

Alright, I have the ground down 30mm, should I bolt it back on to take it off, or should I be afraid of breaking the studs?

There is no need to remove the piston spring cap to replace the push rod O-ring nor is there any point in doing so either - no seals in piston bore. With valves and pump removed it can be flushed out thoroughly. A tech bulletin was issued years ago after many problems with leaks there stating thread should be sealed with red Locktite. These will be very hard to remove.

[Diesel911]

When I did mine I removed the big nut and pulled the Piston out partly because I wanted to inspect the Piston and the Spring (ounce in a while the springs break). I also did it becaues it is easier to get the O-ring in if you can also push from the Piston side with the Piston rod.
If the Pump is already off I would put the Pump in a Vice to remove the 30mm nut (if you chose to do so).
Also while I only took it apart to change the O-ring I took the whole Pump apart to take a look. I had no rebuld kit so I too some 400grit emery paper and sanded the face of the plastic valves to be sure they were flat.

If you put the Pump back on the IP to remove the 30mm Nut I doubt if it would break the studs if the Stud Nuts were tight. Otherwise I think it could twist the Studs.

The 30mm Socket I have is actually a Deep Socket and when I tried to get that Nut off while the Lift Pump was on the IP I felt I could not get into a good position to loosen and I knew using the Vice would work so I just did it in the Vice.

Also I had no rebuild kit so I heated the Copper Crush Washers Red hot. This according to my old Bosses Navy Machinist Manual softens them so that the can be reused. It does not matter how they are cooled as long as they get Red hot.

Note: Do not do this heat treating with Delivery Valve Crush Washers unless there is no other choice.

I took this pic for those who might want to remove that 30mm nut to one of the safe positons it can go in on the vice. However, without some Copper or Aluminum Jaw Pads this Pump wants to slip out of the Vice.
I could not find my Aluminum Pads when I took the pic.
The one I put the O-ring in is on the Car. In the pic is the Pump from my spare IP.

[JEBalles]

Alright, I got that 30mm off with out a hitch and I'm down to the output port (pic) bolt (19mm). It's stuck on there good. I ground down the side of a 19mm socket to get it on there, but even that didn't hold. I've beat it up pretty bad and I'm afraid I already damaged the threads on top. Also, I can take out the piston and the rod, but cannot get the rest out.

[jt20]

mount it back on the IP and loosen (crowsfoot?)


or, screw it to a big block of wood... you get the idea.

I broke a carrier trying to get one of those nuts out.

[Diesel911]

Originally Posted by JEBalles

Alright, I got that 30mm off with out a hitch and I'm down to the output port (pic) bolt (19mm). It's stuck on there good. I ground down the side of a 19mm socket to get it on there, but even that didn't hold. I've beat it up pretty bad and I'm afraid I already damaged the threads on top. Also, I can take out the piston and the rod, but cannot get the rest out.

The Fitting you are showing in the picture does not seal on the threads It seals in the inside tapered area. This means as long as the nut can be tightened down over the threads it well seal even if the outside threads are dinged up a little bit.
If you are having an extremely bad time of it removing the Fittng. I would just leave it alone. The valves are made of plastic and unless something has happend to the Spring inside like it rusting in two they is normally not much of a problem with them.

To remove the Roller and Tappet there is an external semicircular wire spring that Retains it. You have to without bending it remove that and ounce that is done it will slide out.

In the firs pic I point to the Retaining ring.
In the 2nd pic you see the retaing ring and the Groove that the Retaing ring goes into. (You also see that little O-ring that can cause the Diesel to Leak into your Engine.)
The little hook on the Wire Spring goes through a hole in the Pump body and that is what retains the little tappet and roller.
Note there is a lot of parts on the Tappet and Roller that just slide in and out to assemble; this means that they can easily slide out and get lost if you are not careful.

[JEBalles]

Originally Posted by Diesel911

The Fitting you are showing in the picture does not seal on the threads It seals in the inside tapered area. This means as long as the nut can be tightened down over the threads it well seal even if the outside threads are dinged up a little bit.
If you are having an extremely bad time of it removing the Fittng. I would just leave it alone. The valves are made of plastic and unless something has happend to the Spring inside like it rusting in two they is normally not much of a problem with them.

To remove the Roller and Tappet there is an external semicircular wire spring that Retains it. You have to without bending it remove that and ounce that is done it will slide out.

In the firs pic I point to the Retaining ring.
In the 2nd pic you see the retaing ring and the Groove that the Retaing ring goes into. (You also see that little O-ring that can cause the Diesel to Leak into your Engine.)
The little hook on the Wire Spring goes through a hole in the Pump body and that is what retains the little tappet and roller.
Note there is a lot of parts on the Tappet and Roller that just slide in and out to assemble; this means that they can easily slide out and get lost if you are not careful.

Good call 911. I just wanted to rebuild the whole thing since I was going to have to buy the whole kit. But I'll just leave that part alone, it seemed to be working fine anyway.

And it seems that this indeed was the cause of the diesel leaking into the lube oil... there was no ring in there at all! I was deathly afraid it was the IP elements. That being said, I'm assuming that the ring goes on the rod on the roller side of the housing, yes?

And does anyone happen to know the torque for the bolts on this thing?

[Diesel911]

Originally Posted by JEBalles

Good call 911. I just wanted to rebuild the whole thing since I was going to have to buy the whole kit. But I'll just leave that part alone, it seemed to be working fine anyway.

And it seems that this indeed was the cause of the diesel leaking into the lube oil... there was no ring in there at all! I was deathly afraid it was the IP elements. That being said, I'm assuming that the ring goes on the rod on the roller side of the housing, yes?

And does anyone happen to know the torque for the bolts on this thing?

Better find out if the little O-ring come in the rebuild kit!
The 5mmŲ x 1.50mmŲ 'O' ring is located in a groove in the bore that the Rod rids in.
In the pic below the O-ring is removed and the yellow arrow points to were the groove is barley visable.

[JEBalles]

Oh, well this does not bode as well-- my old o-ring looks almost exactly like the new one, maybe slightly stretched.

[Diesel911]

Originally Posted by JEBalles

Oh, well this does not bode as well-- my old o-ring looks almost exactly like the new one, maybe slightly stretched.

Slightly stretched can make a differance. The old O-ring may be worn on the inside.

[Diesel911]

When I did mine I only changed the little O-ring. I did an internet search and found out that some BMW Motorcycles used it on their Carburators; and there is a BMW Motor Cycle Dealer not far away. So that became my local source.

Lift Supply/Sump O-ring from BMW motor cycle carburator
BMW motorcycle parts 5x1.5 O-ring, cold-start enrichener shaft, part# 13 11 1 257 819

[jt20]

is there anything special about that o-ring? It has a metallic luster to it, doesn't it?

what is the material / type?