Fuel pump leak.

[olazz]

I've searched this site and seem to have  come across loads of info on fuel pump leaks.

My pump has started leaking

http://img.photobucket.com/albums/v688/Derfs/fuel%20pump%20leak/IMG_2011.jpg

From what I have read, this now requires a rebuild, however the older style "long pump" like mine can not be rebuilt.
I telephoned Roger Edwards & send pic,  and have been advised that the pump should just be blanked off with a pipe and screw, as many of them are.

So I'm unsure what I should be doing here.

Rebuild unit(if actually possible)
Replace with recon unit
Replace with new short pump
Replace with new Bosch pump (cheaper than OEM)
Blank off overflow pipe

What is the consensus on here about the most correct solution.

Thanks

Lazz
 

[Naj ✝︎]

Hi, Lazz,

These long pumps can be rebuild. See tech manual for 'how to' and parts required.

It is leaking from thru the small 'o' ring on the armature.

Naj

[George Des]

Lazz,

I sent you a msg answering your question. Whatever you do, do not block off the leak off pipe. The fact gasoline is coming out of the leak off, means that gas is getting by the main seal and getting into the motor section. If you do block it off, the gas will eventually fill the can and start flowing out the terminal areas, or worse. As Naj said, the pumps are rebuildable. As an alternative, you can replace the long style pump with one of the newer, small style pumps which are readily available--at a price. Some have fitted pumps from other cars, but I would recommend rebuilding your pump or replacing with the smaller--that way you've got a pump that was designed to work specifically with the car and you avoid other possible issues.

George

[olazz]

Naj & George,

Many thanks for the replies, I will go down the rebuild route initially and hope that fixes things.

Still unsure why a W113 specialist firm, would recommend just blocking off the overflow pipe "as many others are like that". Odd indeed!

[George Des]

My guess is he had it confused with the smaller style pump that has a fitting that looks similar but is used to prevent vapor lock. The leak off pipe on the large style pump is there to allow outflow of any minor amounts of fuel that get by the main seal so it does not get to the ball bearings that lie right above the pump section. If the fuel were allowed into the bearing and motor section, the fuel would wash the grease from the bearing and eventually the motor would seize.

George

[olazz]

My guess is he had it confused with the smaller style pump that has a fitting that looks similar

George

My thoughts at first but not possible; they have seen the car twice and on the second occassion fiddled with the fuel pump as they said it was touching the protective cannister and so moved it to stop any damage occurring . I also sent pictures of the pump. They know very well its an old tall pump not the new one as we discussed replacement costs. Their advice was still... just block the overflow as many others are like that!

I will take it up with them and see what basis they have for giving that advice, if as I suspect all their customers have had the same advice, there must be a number of cars running with this problem.
Thanks again Des

[George Des]

Lazz,

I believe you have an expression over there in the UK for this that is not common here in the US. It is either a "bodge" or a "dodge". It may work short term but eventually you'll need to repair or replace it.
 Let me know how your discussion goes with the repair guys.

George

[olazz]

Right,

Got all the necessary O rings, removed pump and followed the tech manual to the letter.

Managed to remove all the screws from the underside of the pump.

Removed bellows, no leaks or holes.
Replaced O ring under bellows
Replaced locating washer, circlip, impeller etc etc.
Replaced main O ring and installed new bolts to bottom of pump.

Reconnected and Ran the pump.... fuel pouring from the overflow worse than before!!!

The small O ring I installed looked a smaller cross section than the original I removed. I ordered the correct part and size as per tech manual.
I made sure the bellows were fully seated on the O ring before installing circlip.

So what have I done incorrectly or is the pump unserviceable??

George???

Naj???

Anyone else??
 

[George Des]

Lazz,

The leak is probably from the small oring on the armature. I do NOT follow the tech manual advice as far as trying to use a specific size for that shaft oring. This is a critical interference fit and the only way I have been able to do it satisfactorily is to fit a slighlty oversized oring with an inner diameter that fits very tightly on the shaft. The ones I use actually have to be stretched to fit. The reason this needs to be a tight fit is because of the next step. After fitting this oring, I size the outter diameter by chucking the armature in a drill press and using some fine grade sandpaper to gradually wear enough material away that the bottom of the bellows will slip past it but the top portion will not. You also need to make sure that you stretch that bellows seal a bit so it puts pressure on the black sealing face once it is locked in place. Hope this helps.

George