cypermethrin Posted October 16, 2011 Share Posted October 16, 2011 Noticed that the fuel lift pump on my 90 300 tdi is weeping from the bottom of the unit between block / gasket / block. I have tightened up the two 10 mm securing bolts but don't want to shear them. Can anyone advise the nm torque or similar which I should be aiming for ? Thanks Quote Link to comment Share on other sites More sharing options...
Boro Posted October 16, 2011 Share Posted October 16, 2011 According to my haynes 25nm Quote Link to comment Share on other sites More sharing options...
western Posted October 16, 2011 Share Posted October 16, 2011 25nm or 18lbft so genuine book says. it might need a new gasket between pump & block. Quote Link to comment Share on other sites More sharing options...
Tetsu0san Posted October 16, 2011 Share Posted October 16, 2011 Is it weeping fuel or oil? If it's oil then change the gasket and/or seal it with some silicon sealer. If it's weeping fuel then tightening or sealing it to the block will make no difference. That could be a leaky union on the in or out pipes, or even a split in the casing of the lift pump. If it is split in the casing then it's a new pump time. Quote Link to comment Share on other sites More sharing options...
crowmann Posted October 16, 2011 Share Posted October 16, 2011 Get rid of the pesky mech one and fit.......... Actually there are three in these pics the one on the left front is the main pump the one behind secodary tank and the biigy is a transfer pump. Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted October 16, 2011 Author Share Posted October 16, 2011 Thanks for the advice Took a closer look today and its definitely oil and not fuel that's weeping I also notched the oil level is about 1.5 cm above the max dip stick level. This is down to the numptie garage which I will not be frequenting again. Prior to the oil change it was not leaking noticeably on the driveway Is it possible that this over filling has enabled the oil level in the block to actually exceed the level of the fuel lift pump and hence it's become more visible ? Also noticed the vacuum pump located adjacent to the fuel lift pump was weepin Could the over filling be responsible for both weeps or are the levels nowhere near the engine blobk hole and cam etc ?. Quote Link to comment Share on other sites More sharing options...
Boro Posted October 16, 2011 Share Posted October 16, 2011 Over filling will cause increased crank case pressure which probably explains the leaks, the oil level wouldnt come that high up the engine no, get yourself a clean container and drain a bit of oil from the sump, reason i say clean is then if you drain too much you can aways pour a bit back in, just be careful not to get any much in the oil if you do that Quote Link to comment Share on other sites More sharing options...
western Posted October 16, 2011 Share Posted October 16, 2011 you'd need a lot more oil to get the oil level to the lift pump location, then it would be much higher on the dip stick. Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted October 16, 2011 Author Share Posted October 16, 2011 Thanks guys Is it really possible to loosen the sump plug and let a little oil out ?? When I have done this on other cars it usually all or nothing..... Or am I being inept ? Quote Link to comment Share on other sites More sharing options...
Boro Posted October 16, 2011 Share Posted October 16, 2011 Its possible but more than likely too much will come out, clean the sump around the plug area then use a clean container and a funnel, loosen the sump plug and unscew it by hand but keep it in the hole to control the amount of oil that comes out, i would guess you want to drain about a litre before refitting the plug and checking the level Quote Link to comment Share on other sites More sharing options...
cypermethrin Posted October 16, 2011 Author Share Posted October 16, 2011 There you go making it sound so easy ! Thanks Boro will give it a whirl... Quote Link to comment Share on other sites More sharing options...
Les Henson Posted October 16, 2011 Share Posted October 16, 2011 you'd need a lot more oil to get the oil level to the lift pump location, then it would be much higher on the dip stick. Not too sure that a higher level of oil will cause it to leak out of the lift pump gasket join. Increased crankcase pressure would have a minimal effect, but would increase the likelyhood of a weak seal somewhere start to leak. Most common cause of leak at the gasket join is because someone has over-tightened the bolts, which then bends the alloy housing where the gasket is. Further tightening just tends to make it worse. New gasket and possibly some rtv to help might fix it, but if the pump gasket mating face it too bent, then a new pump is the only cure. Les. Quote Link to comment Share on other sites More sharing options...
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