Have managed to eliminate many oil leaks on Ruby but the one that currently remains and is being very persistent is one from the petrol pump.
I had already purchased and fitted a kit including diaphragm etc and in the last month or two replaced the gasket between the pump and sump joint along with blue hylomer and am pretty happy the leak is not from this joint as there is no sign of any oil around the joint either from or under the pump and the sump is clean.
However the leak appears to emanate from around the pin that the cam lever oscillates about runs down and drips down from that area. It appears to be quite significant in that a run of just 15 to 20 miles is enough to form a decent pool of oil at the bottom of the sump.
As always any comments and advice much appreciated
Cheers Denis S
Joined: Aug 2017 Posts: 1,230 Threads: 33
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6 Location: Salop
Car type: '28 GE Cup. '28 AD Chummy '30 RL Saloon. '34 RP Saloon. Too Many toys!
Engines which are heavy breathers do blow a lot of oil mist into the pump, this can cause a leak from the pin, particularly if the engine is a very heavy breather.
Or the normal breathing of the engine is not as good as it should be - sometimes the valve chest breathers for example are blocked off by owners.
I have seen 'oil control' gaskets, which are basically a piece of rubber with a slit in them for the operating lever. I'm not sure how good these are at preventing this, my guess is they are not very good.
Also there should be a seal between the body of the pump and the rod thats on the bottom of the diaphragm. That is often missing (and isn't included in any of the T or U type repair kits I've seen. With this missing it allows oil mist at the area under the diaphragm. There is a drain hole in the area in question of the pump bottom casting, (this is I am lead to believe to be a tell tale to see if the diaphragm is leaking and to prevent filling your crankcase with petrol if it is). and the oil will eventually leak out of the drain. You can fashion a seal here out of a bit of rubber, a couple of washers (which you need to file a slot in, and a suitable spring.
Having stripped a spare "T" type AC fuel pump to check it out prior to removing the pump on the car, I decided to purchase replacement parts for both units, keeping one boxed up ready for use and sort the leaky one on Ruby.
However, I had noted that the "spare" did not have an external priming lever, but still proceeded with the view it would still be a useful unit to have, but just checking to make sure I put it back together in the correct orientation it dawned on me the "spare" was in fact opposite hand to the pump currently installed, i.e. the in and out connections are reversed and to accommodate the spare I would need to rework the fuel pipes in and out.
See attached pic of both units.
Does anyone know why this would be, is this unit used on any other A7's but both are clearly marked type "T" ??
14-04-2022, 06:29 PM (This post was last modified: 14-04-2022, 06:38 PM by "Slack Alice" Simon.)
I would be surprised if "T" type pumps were exclusive to Sevens. Also, several AC pumps appear to have interchangeable tops, with different outlet positions for different vehicles.
Silly question: are you sure you can't get the positions you need by just rotating the top? Edit: silly question indeed, I went back to look at your photo. Oops!
My car has the earlier "M" type pump, which has the reverse of the "T" type in and out positions, so I have made a short conversion pipe for the inlet side, and a different outlet pipe up to the carb, which allows me to use either/or, without modifying the original pipe runs.
Having just checked to see if I am right about this, I find that I could have any pump variation at present, because, due to the fuel tank being quite rusty inside, I have flexible pipes and filters on both inlet and outlet sides of the pump.
On the oil leak: a car nearby has the leak you describe, the owner puts it down to his version of the "T" type not having the oil return groove to meet up with the oil return hole in the crankcase, so oil buils up and leaks out of the spindle holes.
He hasn't yet got round to modifying the pump, which shouldn't be a difficult job.
Just spent several intermittent hours trying to stop my "M" type pump from leaking engine oil. Removed several times and checked/renewed gaskets although no defects were found. Noticed that the oil drain hole below the main opening for the cam lever arm was partially blocked by the original gasket , and the drain gallery from the pump too it. Modified both to improve drainage. Refitted and road tested .STILL got oil leak. This time however, found oil weeping from tappet cover immediately above the pump. Not seen this dripping before. It ran down directly onto pump flange . will attend to this tomorrow, hoping that it's the dammed leak. Can't believe I didn't spot it earlier. Thought you might like too know, so you can check your T'cover in case.
I've got a slight leak like that, Peter, but not from the bottom of the valve chest. It seems to puddle on the moulding that creates the trench on the other side for the gasket, so I'm wondering if it's actually coming from the retaining screw/cover interface. Either that or it's blow out from the venting holes being blown back by the 4 blade fan, but I doubt it because the engine is recently rebored. I have "modified" the fixing screw to see if that sorts it, using a fibre washer and a circle of silicone (belt & braces).
I have had an oil leak emanating from the petrol pump which I was confident about the gasket seal. Turned out to be leaking through one of the studs. Replaced studs with Loctite, no further leaking.
I had wondered for some time if it was the valve chest cover leaking and creating much of the problem so today I replaced the valve cover gasket with a new silicon version.
I had already checked the drain from the pump which was clear but I also replaced the pump gasket with a rubber gasket with the split that allows the rocker arm to pass through but limits the oil ingress……..allegedly!
I have not taken her out to check for leaks as am currently changing all oils, hence my other post re oil levels.
I have always found the lever pivots a source of leaks on other makes.
Where rubber is mentioned presume mean oil resistant nitrile.
Not all carbs had the auxillary seal. The spring combination is important as the little spring contributes.
Of all the cars ever made Sevens with fixed crankhandle have the least need for a hand primer.
Perhaps timely to repeat that various arms and the correct ones bear in the middle of the pad. Care necessary to fit on correctb side of camshaft. Different cars had different springs; esp those with crankcase vacuum.
