Cleaned my sending unit...should it work right awa?, 1982 300D - PeachParts Mercedes-Benz Forum

300DPETE · #1 01-08-2006, 10:08 PM

Hi, guys.

I cleaned my sending unit recently and reinstalled. The reserve light came on initially, and now it's off, but is showing that I'm empty, despite nearly 5 gallons in the tank. Does it take a while for the sending unit to fill with fuel again, or is something not right?

Also, I managed to break the copper wire in the unit, but was able to solder it back on its connection at the bottom. I'm wondering if a bad solder job is possibly the culprit.

Thanks,

Pete.

300DPETE · #2 01-09-2006, 01:44 PM

Bump.

boneheaddoctor · #3 01-09-2006, 01:51 PM

doesn't sound right to me either....it should read correctly right away.......and in that I mean within a minute in any case....

300DPETE · #4 01-09-2006, 02:01 PM

Quote:

Originally Posted by boneheaddoctor

doesn't sound right to me either....it should read correctly right away.......and in that I mean within a minute in any case....

Crap. Looks like I'll be putting down $80.

Thanks, though,

Pete.

rg2098 · #5 01-09-2006, 02:07 PM

Sounds like a bad solder job that messed with the resistance in the wire somehow.

MattBelliveau · #6 01-09-2006, 02:45 PM

I'm going to agree with rg. Check the connection on the top of the sending unit.

meltedpanda · #7 01-09-2006, 02:57 PM

which wire did you break? the two that run inside the copper contacts on the float are actually one wire , the guide wire is not . did you clean out the float housing and open the fuel inlet holes?

300DPETE · #8 01-09-2006, 03:23 PM

There are two silver looking guide wires (or one as you say) and a copper wire. I broke the copper wire. I'll try soldering it again.

Pete.

P.S. Yes, cleaned the unit thoroughly.

meltedpanda · #9 01-09-2006, 05:35 PM

I think I may have one lying around in my shop if you need one or need the pieces parts

Austin85 · #10 01-09-2006, 09:24 PM

Quote:

Originally Posted by meltedpanda

which wire did you break? the two that run inside the copper contacts on the float are actually one wire , the guide wire is not . did you clean out the float housing and open the fuel inlet holes?

What do you mean by fuel inlet holes?
Where are they ??

aa

meltedpanda · #11 01-10-2006, 10:02 AM

small holes in the tin cannister that houses the float. I think there are two on the sides, one on the bottom

signalredcoupe · #12 01-10-2006, 10:23 AM

I believe the maintenance manual will give you ohms values for the sender if you want to get into it that far. If the tank was totally empty & 5 gallons was put in, the low fuel light will be out, but the needle may not register much higher than empty. Paul
'84 300CD 290,000

1983/300CD · #13 01-10-2006, 11:36 AM

Yes, by all means, test the equipment...

But, there is a reserve portion of these tanks. Maybe you need to fill up? Mine will sit at empty for quite a distance while I still have fuel.

I'd try filling up and hitting the trip counter first.

Oops, sorry Signalred, didn't read all of your post... (already suggested.)

300TDT 1987 · #14 01-10-2006, 04:32 PM

I cleaned out mine two weeks ago, it it didn't read correctly until I filled up the tank. Now it works fine but I need to clean out my tank filter this spring when it warm

linguica · #15 01-28-2006, 08:33 PM

I was cleaning the sender today, and somehow lost the nut on the bottom that holds the tube on.

Would there be any harm in using a plain old hex nut? Anyone know the size? Am I correct in assuming the copper wire just a guide wire? I will try to reattach it tomorrow. Had somewhere between 1/4-1/2" of fungus in the bottom of the tube...no wonder my reserve light wouldn't come on.