Hi Guys,

As usual what should be a quick and agreeable 928 job of changing fuel filter on 88 S4 is turning into a frustration exercise because of a stuck nut!

I'm trying to loosen the 19mm nut attaching the fuel line to the passenger side (US) of fuel filter on 88 S4, while counter-holding with 19mm wrench on the inner nut of the filter.

It won't budge.

Have sprayed the nut with penetrating oil but it still won't turn.

Any ideas please for freeing this nut? I'm off to buy a longer wrench to get some more torque, but if anyone has any other suggestions I'd be very grateful!

Thanks in advance,

Adrian

 

It always helps to get a helper to hold while you push/pull.

 

Use a flare nut wrench............they're on tight for a very good reason......fire.

 

I thought a flare wrench would be better on a pipe fitting, but my local auto store only had them up to 17mm!

I will pick up a larger one during the week. For now I have a selectgion of other plumbing type wrenches to try.

Thanks for suggestion though which confirmed what I thought.

Adrian

 

Will nab one of my neighbours! My wife helped with the counter nut but was difficult for her as I tried to undo the other nut.

Adrian

 

If you have a Sears nearby, they may have your flare wrench.

 

I have found that nut to be so tight ... that I've removed the filter and 'S' pipe together for a group hug in a bench vise. These gland nuts feel as if welded ... and it's not a good spot to use heat ... and it is unpleasant to collapse the pipe.
Be prepares to clamp off the tank hose with vise grips if the pump starts dribbling ...

 

This sounds promising Garth, thanks.

Do you mean to take off the s-shaped fuel line from the pump? Problem is the tight nut is the one between the filter and the fuel line to the engine so how do you remove the entire assembly? I'm missing something that must be obvious to you so forgive me!

Having decided to leave things overnight I put tools away, reconnected battery and fired her up to reverse into garage. Thought I'd better check the filter area for leaks and there was a little stream of fuel drops coming away from the check valve area. I think moving the whole filter/s-line/pump assembly around when trying to get the nut free has slightly loosened either the check valve or most probably the cap nut securing the s-line to the other end of the check valve so need to check all this out first. Sigh.

Adrian

 

Whoops - I was thinking of the filter inlet side, for the outlet has always released quite easily .... lucky, I guess.
Look carefully at the new filter - there should be a hex fitting threaded into a hex flange on either end, and that fitting receives the fuel line gland nut: the first filter I ever tried to remove didn't budge ... of the three places to fit two wrenches, guess which two I chose

 

I used a flare wrench AND a vice grips (around the flare wrench) to make sure nothing flexed. It was a PITA but it worked. once it "pops" the rest is easy.

 

Just a quick update for anyone doing similar job.

I've ordered a 19mm flare wrench to try to loosen the filter outlet nut.

To try to fix the leak around the check valve area I held the pump by hand while I tightened the cap nut against the banjo fitting at the pump outlet end. I was surprised that it moved about a quarter turn. Reconnected battery, fired up (not literally!) and now no leak whatsoever. That was good news as if the leak had been where the check valve is tightened against the pump then it takes a little more work to tighten it since access is hampered by the electrical posts on the pump.

But since I must have disturbed at least 1 of the 3 crush washers I think that if/when I get the filter outlet nut loose I'll take out the whole pump/filter assembly as advised and renew the crush washers for peace of mind. At the moment the filter/pump cover is off (could do with a new one of these too as well as tank retaining cage which is pretty rusty) but when it's on it would be a lot harder to spot any leaks before something catastrophic happened.