My '79 300D has moist return line hoses between injectors, especially close to the fuel filter(main).
So I decided to change my filters and bleed
the air out using the hand pump.
They are still moist.
I did buy new braided hose but have not replaced them yet.
The current return line hose are only about 2 years old (8000 miles).
My hand pump does have fuel inside the top of the handle and
does leak fuel when pumping it.
It shows no sign of leaking fuel after it is locked tight and dried.
I believe all the air is out of the lines as I bled it 3 times by the book.
Do I need a new handle for this Bosch
hand pump or do I need to replace the whole unit?
I am not clear whether the handle can
be pulled out or whether the whole "primer pump"
a.k.a. fuel pump needs to go?
The car runs fine and starts up fine. I get the smell of fuel into the cabin once in a while due to the moist return lines.
Not enough info on the archive search to straighten me out.
Thank you.

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Greetings,

If you have fuel leaking from the hand pump, the o-ring seal at the bottom is most likely shot. It may or may not be leaking or seeping air into the fuel system after you tighten it down. A new primer pump handle that is not a screw down model but spring loaded is available through parts shop for $12 plus change. The new version is easier to use and is also made by Bosch, reduces possible leakage. The return lines you speak of, if they are the clear ones returning fuel to the filter housing from the IP are leaking, they have become brittle at the nipple end and need to be replaced. These can also be ordered from Parts Shop by the meter. If it's your injector to injector bleed lines that are wet, use the replacements you bought and change them out. While you're under the hood, check the prefilter hose clamps for tightness as well as the return lines. They have a habit of vibrating loose over a period of time.


Charles

Thanks can-do, my clear lines are fine, I did service the clamps on all lines. The bleed lines are wet
so I'll replace those after I get a hand pump handle from part shop. Does the handle just pull
off after unscrewing or does the shaft
have to come off also? Once I get the part it may be obvious but I'd like to know in advance.
Thanks

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD

Greetings,

The pump handle unthreads at the base of the pump where you probably see a copper sealing ring exposed. You will need to reuse your nylon pump button after you remove the old hand primer. You'll see what I mean once you remove the old hand pump.Ensure you use the new copper sealing ring sent with the new pump.


Charles

Thanks Can-Do, goin' to Houston tomorrow
so I get to this repair a bit later.
regards.
Denis

__________________
1979 300D 220 K miles
1995 C280 109 K miles
1992 Cadillac Eldorado Touring Coupe 57K miles SOLD
********************
1979 240D 140Kmiles (bought for parents) *SOLD.
SAN FRANCISCO/(*San Diego)
1989 300SE 148 K miles *SOLD