I'm planning on replacing the prepump in my '90 245. I thought I'd check the board for some tips and pointers. The Bentley manual indicates that I must disconnect the fuel return hose "from under the car." Is it necessary to go under the car...Isn't this line directly attached to the pump/sender assembly? If you've done this job and have other advice, I'd much appreciate it. Thanks.

Looking forward to a quiet main fuel pump,

Charlie

Thouhgt i'd put my 2 cents in here. I just done my 91 240 last week. I live in corrosionville canada and have 400,000K on my beauty. I bought a VDO pump from autopartsway.ca. It was 200 bucks taxes in, freight in and arrived next day. It was exact to the one i took out.
I could barely see the tank bung for corrosion. I soaked the whole area for 2 days with Krown. Then a dremeled and scraped as best i could. Digging out from the lip where the bung sits. The bung has to rotate 90* so about 1 1/2" of turn. I removed both hoses 1st and both elbows snapped off. They dug out of the hoses w/o problem. Good hoses/ all original
Then i started beating the crap out of it. It was realy stuck. Noisy too. I finally used a brass punch and a 1LB ballpein to get it to come off. Be careful not to damage the tank lip. In hindsight i should have ordered a bung as i distorted it bad. But it is Volvo so I just re-shaped it. filed any edges i'd made, wire wheeled it and re-used it. The seal is under the pump so it was fine.
Removing the assembly is a bit finicky so be patient you don't want the pre filter to drop into the tank. When you start giggling, go for a walk and get the gas out of your lungs! Putting the new one in was equally finicky but remember how you removed the old one and copy the install. It will go. I was told to leave a 1/4 tank of gas in it so the float doesn't get caught on the bottom baffle. Too much gas and you will be fighting the float. Once in, I painted and rust inhibited the whole area and shazam the mainpump is quiet, no fuel smell and I have a fuel guage again. Good luck

...about "fuel lines" and how to disconnect them.
There are two fuel lines:

1) The rubber pump OUTPUT line.
Cut or saw off the rusty hose clamp, use a screwdriver to "assist" the hose off the sender fitting. Refit hose to new fitting. Refasten to new sender with new hose clamp.

2) The rubber covered hard plastic RETURN line.
I have never gone below to tangle with the rusty fitting that connects plastic line to (often fragile) metal line.

I use a razor knife to cut off about 2" of outer rubber covering to expose black plastic line.

Then I cut the plastic line at end of metal sender barb (I use a small, fine-blade hacksaw.)

Reconnect the cut plastic end to new sender barb with short piece of 5/16" I.D. fuel hose and 2 good hose clamps. NOTE: Return line is low pressure. IMO, FI rated hose is not needed here.
--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Most of what 'Lawrence' told you was good advice, except that I suspect that his experience involved a car that already had the OEM fuel line removed and replaced. Either that, or he was very lucky getting to reattach it (and I would suspect it's reliability).

The advice you heard was right -- but with the caveat that, if you are willing to replace the fuel line, then you can disconnect it above at the fuel tank bung. The problem is that the OEM fuel line is peculiar -- it has a shrink-wrap type of inner liner, so that it's virtually stuck to the fitting on the cover of the fuel tank. You can, of course, cut it off there, but the fuel line can't be reattached -- or at least, not without difficulty and suspect longevity. You have to replace the whole line, so you'll be crawling under the car to attach a new line anyway. Good news is that you can use ordinary high-pressure fuel hose with good clamps.

I also recommend getting the bung wrench, rather than driving it open with a hammer and drift -- the thought of distorting it concerns me, whereas the wrench makes it easy and neat. And be sure to also have a new bung gasket, a new sock (fuel strainer), new short hose (transfer pump to line) and appropriate hose clamps. And be sure to note carefully how the sock was fitted, so you replace it the same way (or else it might get twisted against the baffle walls and restrict fuel flow).

Good luck.

"Good news is that you can use ordinary high-pressure fuel hose with good clamps."

I don't see any reason to use high pressure fuel injection type hose at that point. The in-tank pump is a low pressure transfer pump. Certainly the short section of hose in-tank between the pump and the metal tube is a very low pressure type.

High pressures aren't encountered until after the main fuel pump. When I did mine I used conventional fuel line from the local NAPA. I don't recall the sizes as I simply snipped out sections of the pressure and return hose and took them to the store with me. There wouldn't be any harm in using fuel injection high pressure rated hose, but I think it would be a waste of money.

John

Here! Here! Mom always said "two heads is better than one, even if one(mine)is a goat head".

You might also consider leaving the fuel line attached and doing the work in the trunk.

And you are probably right about using the proper tool for fuel tank plate removal. But, Ive done several,and the hammer and drift method has worked well. I would say that one should make every effort to insure that any force applied is directed alongthe same plane as the top of the gas tank. On the other hand, if you have the time and money, get the tool. It certainly wouldnt hurt.

Thanks

Lawrence

re: "...You might also consider leaving the fuel line attached and doing the work in the trunk...."

When I did mine, an '80 wagon and an '84 sedan, there wasn't enough slack in the fuel hose's length to withdraw the unit out of the tank. It had to be detached, at one end or the other.

and for the bung nut wrench, it's $24 (+ shipping) from IPD:
1-800-444-6473, tool # CBT5169

and for the new rubber sealing ring, $6, #CB949276.

So I'll prepare to have some fuel line and hose clamps on hand. NAPA has fuel line rated for 50 PSI (more than enough for the prepump). What size do I need in terms of internal diameter? I live in New York City...I'm gonna try and do this on the street. If it gets too hairy, I'll just drive to my parents garage in Pennsylvania where I do most of my wrenchin'.

I'm afraid I don't remember the internal diameter.

Working on a NYC street? Have you done that often?
I hope it's a "safe" neighborhood (are there any left? The first 25 years of my life were spent in New York City, but moved out 35 years ago). I wouldn't leave my tools outside while I went in the house to look for another tool -- if you know what I mean. I'd recommend doing it at site B (your parents' place in PA).

Good luck.

Actually, New York City is one of the safest cities in America. Google FBI crime statistics. At the same time, tools left alone wouldn't last a minute. I generally work on the Volvo in Pennsylvania with my Dad's garage, tools, etc. However, I don't want to make the 100 mile drive without the prepump working. I'm afraid I'll blow the main pump (a $300 part last time I checked).

One concern: Mayor Bloomberg banned smoking in public places but not on the street. Smokers are aplenty on the sidewalks...I could just imagine the explosion as an ash gets flicked onto the gas puddle that would inevitably gather as I change out the prepump.

Perhaps I can get away without removing the fuel line...there might be enough slack so that I can remove the sender/pump assembly from the tank and swap out the prepump.

Thanks,

Charlie

disconnect the battery. Make sure you work in a ventilated area. Take periodic breaks for fresh air, if necessary.
working under the car is not required(save that for the main pump).
I would try to decrease the amount of fuel in the tank much as possible(just drive the car until you get somewhere between 1/4 and empty). makes it easier.

On all occasions Ive used a large screw driver(or pry bar) with a hammer to loosen the fuel cap on the tank top. That method has always been successful for me.
Remove the fuel line from the fitting on top first. The hose(s) can be stubborn. Just persist. It will come off. Disconnect the wire connector. Lift the plate(cap)/pump/float assembly out of the tank. It all comes out together.

Ive always found reinstalling the pump into the tank to be a pain in the a...
Theres a baffle(partition) on the bottom of the tank, the float has a tendency to go to the wrong side of the baffle. However, its not a major problem. Just may take a few tries. Make sure everything is in the right place and fitting properly.
Be careful. Be patient. Be gentle, as possible , with your pump/float assembly. Dont forget fresh air for your lungs.
Its not rocket science.

good luck