John, you are right, about the other type of pump. There actually
are 3 types of pumps used in 615 to 60X engines, The oldest is the
hex head "union", or part between the actual delivery valve/pump body
and the injector line. In the middle was a type where the "union"
was also the calibrating device, not to be touched except by a Bosch
shop on a test bench. Thankfully that was a short lived experiment.
The third, splined "unions" is used on 85 to 87 and somewhere into
the 90s Diesels. (123, 124 and 126) and later.
My memory is dull, but I am pretty sure my 80 and 81 240Ds have the
splines. At any rate, the procedure is pretty much the same, just
that on the OM621 and 615, there is no Oring to contend with .
Somewhere between 76 and 1980, the intermediate type was used, and
then the type M. I make no claim to know what models were switched
to which type at what year. I will go out and look at the 240Ds to
see if my memory is tricking me, then report back.
Correct me if I am wrong, but the procedure that was previously
cited is particular to the Bosch type M pumps, which are readily
identified by the 33-tooth spline "touch-me-not" "fastener" that is
the delivery valve body (or union, depending upon which book you
read from)...
The type M pump has both the delivery valve seal (crush washer) and
an o-ring (which seems to fare poorly with respect to biodiesel and
ULSD...)
The car in question is one of the earlier diesels (most 1985's and
pre-1985 US/NA models); they use a Bosch type MW pump which has a
bog-standard hex outline for the unions. The unions each screw into
a separate steel chamber that is attached to the aluminum body of
the pump with one nut above and one nut below. The MW type pump does
not use the worrisome rubber o-rings, just copper washers. If they
leak (and only if they leak), loosen them and them retorque to 50Nm
in one step. If they continue to leak, order new copper washers (I
forgot the part number) and replace all of them one at a time.
Wear gloves to protect the parts from fingerprints, etc. It's not a
good idea to remove the innards below the union/spring, but if the
delivery valve does pop out, rinse it in clean diesel fuel or clean
fine oil (sewing machine oil) (3 in 1 is NOT suitable) and
reassemble them; check the bottom surface of each union for any
scratching or scoring; the finish must be polished or you will have
leaks. Any unions that are not polished should be replaced, as
removing material from the bottom of them will increase the pressure
on the delivery valve... Likewise any that continue to leak should
be swapped. The unions themselves can be swapped off of a "donor"
pump.
I'd only mess with the pump if it was leaking.
Do you see any air bubbles in the fuel lines? They can develop leaks with age.
Also, if your fuel tank vent is plugged, you can wind up with some
roughness (and starvation) issues; check that before replacing fuel
lines, especially if you have ever needed to disassemble the fuel
level sender and remove algae corpses from it; I've seen the vent
line become sufficiently plugged to hold about 60psi applied to the
vent fitting at the tank.
The quickest way to test the vent line is to take a long drive then
remove the fuel cap; after turning the cap, it should rest on the
opening--you should not need to pull it off, and you should not hear
air movement when the cap comes off.
--
John W Reames
jream...@verizon.net
Home: +14106646986
Mobile: +14437915905
On Sep 5, 2012, at 15:57, Dieselhead <126die...@gmail.com> wrote:
Depends on how clean the lines and top of the IP are. You want
everything clean enough for surgery first. No lint, dust, etc.
I'd say 1-2 hours. Remove the lines (you have already done that.
Remove the DV locks (screwdriver or torx)
If you have the splined DVs, then you need the special socket. If
the DVs are not too torqued, you sometimes can remove them with
the splined lock with a wrench on the tab. This has never worked
for me, and you really need the socket to get the right torque on
reassembly.
> Remove the DV holders and keep in order, or I do one at a time.
Use a pick to pull out the old copper seal. Inspect... find a
culprit? (best to determine the weak cyl first.)
put in a new copper seal, clean the DV holder, put on a new oring.
use a new spring and replace DV holder
Follow specs for tightening procedure and final torque.
So is this DV repair pretty straighforward? How long of a job?
Sent from my iPhone
On Sep 5, 2012, at 12:57 PM, Dieselhead <126die...@gmail.com> wrote:
Probably nothing to worry about. I remember freaking out about a
similar situation, a wet hole, but it was ok when I put everything
back together.
If compression is good, then order DV seals (copper) and DV
springs and DV orings. Rusty has em, but I can look up the part
numbers if he can't find them. I ALWAYS order extra orings and
seals. The copper seal is a one-time use, and generally if you
pull a DV back out, the oring is cut from the threads too. A weak
DV spring will act the same as a leaky DV seal. rough idle.
I'd order 4 springs and 5 or 6 orings and copper seals. There is
always one I want to do over. Follow the proper procedure for
seating the DV seal and the proper torque.
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_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
