Replacing a pneumatically governed OM615 M-pump with an MW off an OM616

[invnsnt]

While taking some parts off a off a junkyard 1978 240d today, I also grabbed its MW injection pump to do some experimenting. The OM615 in my 206D van has a pneumatically governed M pump -- the same model as a 220D. However, this current IP has a large crack in the housing and badly leaks oil. I'm going to attempt to mend the crack with some JB weld, but in the meantime I thought I could see if I could install this MW pump I found. Has anyone done this? The oil lines on the MW pump seem like the biggest hurdle -- not sure if my OM615 has the threaded holes for them.

[Diesel911]

I don't know but over time they increased the power of the horse power of the engines. On the surface that implies that a new pump made for a more powerful Engine would not work properly.

[Diesel911]

Can you post a picture of the cracked on the Fuel Injection Pump?

[invnsnt]

I'll try and get a photo (it's hard with the engine in the vehicle) but in the meantime, here's the location of the crack on a stock photo of the model of pump I have.

The more I read through the FSM, the more difficult it seems to switch from a pneumatic governor to a mechanical one. I'd have to:

- make sure the new pump gets oil through the intermediate shaft
- find or tap a new hole for the IP oil return line
- find a way to actuate the vacuum shut off valve. Currently, the only thing using vacuum on this vehicle is the brake booster.
- maybe rebalance the IP fuel delivery, as mentioned

Might not be worth the effort, huh!

[Diesel911]

Originally Posted by invnsnt

I'll try and get a photo (it's hard with the engine in the vehicle) but in the meantime, here's the location of the crack on a stock photo of the model of pump I have.

The more I read through the FSM, the more difficult it seems to switch from a pneumatic governor to a mechanical one. I'd have to:

- make sure the new pump gets oil through the intermediate shaft
- find or tap a new hole for the IP oil return line
- find a way to actuate the vacuum shut off valve. Currently, the only thing using vacuum on this vehicle is the brake booster.
- maybe rebalance the IP fuel delivery, as mentioned

Might not be worth the effort, huh!

You would need a whole linkages system set up to use the mechanical pump and that presumes the pump would actually work being calibrated for a more powerful engine.


That is a curious place for it to crack. That area should not be under Oil pressure so there is a good chance to fix the leak.


Degrease an area like an inch around the crack. Sand it with some rough sand paper like close to 80 grit and again degrease with brake cleaner.
Degrease again and apply some of that fiber glass cloth heavy saturated with the slow curing JB Weld Epoxy. However, that presents the problem of how to hold it in place while it cures.


JB Weld make an epoxy putty. Follow the directions for roughing and degreasing the surface and follow the directions on the Putty and try to apply a good thick coat like 3/16 inch thick. And press it on good. The Epoxy putty usually stick to where it is applied and is thick enough I think to not crack. Make the repair at least 3/4 inch wide.

[invnsnt]

I pulled the IP today, and you can see the PO's attempt at fixing the damage with some sort of epoxy:


I ground it off in preparation for the repair. Looks like there were three indentations in a row, and the epoxy had flaked off the largest one. Is it safe for me to remove the back panel of the IP to get access to the inside of where I need to repair?

[moon161]

Could a good weldor fill it in?

[vox_incognita]

The damage is of zero importance, just JB weld it.It serves as a sump,no strains and no pressure there.

After you've drained the oil you can remove the back plate.





The gasket will be alright. Repkits still available though.

Remove the six screws and pull the back plate slowly. You'll need to disconnect the vacuum diaphragm from the control rod (it's a c-clip)..see attachments.
On disconnecting the diaphragm make sure you retain the little plunger ,the spring and the washers inside the diaphragm cylindrical end(once out, put a screw in the hole to keep them safe).



Inspect the diaphragm for cracks etc.

Finish the housing crack repair and reassemble.Will last forever. Mount the IP..fill motor oil until it flows out of the control screw (appr. 200ml).

[Sugar Bear]

If you remove the housing, drill a small hole at each end of the crack to prevent further travel. Sand anywhere the epoxy will contact. Then drill a couple of holes along/through the crack. Push the epoxy through all of the holes adding a light coating of epoxy to each side of the crack connecting the drilled through holes...good to go forever.

Good luck!!!

[okyoureabeast]

Don't use JB weld. Find a good welder who will fill it with metal and seal it for life.

[cornemuse]

Originally Posted by moon161

Could a good weldor fill it in?

Heat conductivity of aluminium. You'd have remove everything 'non metalic'.

(I have an 185 amp tig welder, & when I attempt {I'm not good with aluminium!}, I must stop periodically and allow the welder to cool.)

Tearing the unit that far apart, prolly best to replace it. Or look for a useable unit. Or glue it up, , , , ,

[invnsnt]

Opened up the back of the IP (thanks to vox_incognita's explanation!) to prep the damaged section for repair:


Seems like someone had been in here before, since there was alot of sticky silicone sealant in addition to the rubber gasket. I ground down the biggest crack and drilled out some sections where there was some surface cracking.


I'll need to get a new gasket too, since the current one was damaged. Maybe that's why the PO added so much silicone!

[vox_incognita]

Neat !
Google 1417010001 for the full set of gaskets . If you manage to find the backplate gasket alone it might be 1/2 the price of the full set.

[invnsnt]

I finished the crack repair - i think it looks pretty good:


I got it installed back on the engine following the FSM procedure, but I'm having trouble confirming start of fuel delivery. I thought I'd be able to at least see the fuel "welling up" (as I've read in some write ups) in the delivery valve, but it doesn't seem very obvious to me. I'll just order a drip tube.

[Mackan100]

I know this is an old thread, but do anyone know if It's possible to replace the diaphragm without removing the pump from the engine?