Leaking Sump Seals

[swithland]

This is an issue thats been going on for a while. The front and rear cork oil seal gaskets have leaked since the engine was reconditioned. I inititally put that down to possibly the reconditioners not cutting the cork so that it sat proud of the sump pan, but then it appeared that it may be due to crankcase pressure. So I sorted out the crankcase pressure issue by fitting a rocker top with a breather pipe outlet and connected that to the carb. The seals still leaked....

Ive had the sump off about three times and tried resealing using silicon sealant, but that has not worked. So finally I bought some MG sump seals made from rubber which I understand from the forum are a good way of eliminating any leaks. Ive noticed the front is a little different to the back in length, but I also understand that to make the mG seals fit, they need to be cut.

How much do I need to cut off, and should they be flush with the top of the sump, or should they also be a little proud ? Not sure about this and dont want to go chopping them up until I know how much needs to be removed !!

If anyone has done this before, I would very much appreciate some advice.

Cheers, Charles.[frame][/frame]

[David53]

Not sure about the rubber seals. I know the cork ones should be around 1/8 inch proud of the edge, perhaps rubber is the same? Please let me know how you get on with this. I have exactly the same trouble, have replced cork gaskets twice and still getting the leak at the rear. Would love a solution! I presume your car is also an 803???

[Declan_Burns]

I have done it many times and it works.

See :
http://www.mmoc.org.uk/viewtopic.php?f=4&t=35875

You use a hacksaw to do the initial cut as there is a metal reinforcing ring ~1mm moulded into the seal. Then use a file to get it flush or only ever so slightly proud of the sump. I also degreased everything and added some high temperature silicone sealant all around as a matter of precaution. Some will say it's not necessary but you have now seen for yourselves why I always recommend this rubber seal mod as I gave up on cork long ago. Tighten the sump screws hand tight and allow the silicone to fully cure before final tightening. I even ran a bead of silicone on the outside but again maybe buckles and braces. Then it should be fine.
Regards
Declan

[David53]

I wonder if it will work on an 803? Is there any difference in the sumps on different engines?

[swithland]

Not sure about the rubber seals. I know the cork ones should be around 1/8 inch proud of the edge, perhaps rubber is the same? Please let me know how you get on with this. I have exactly the same trouble, have replced cork gaskets twice and still getting the leak at the rear. Would love a solution! I presume your car is also an 803???

Mine is a 1098cc, but as far as I know, the sumps are the same..

[swithland]

I have done it many times and it works.

See :
http://www.mmoc.org.uk/viewtopic.php?f=4&t=35875

You use a hacksaw to do the initial cut as there is a metal reinforcing ring ~1mm moulded into the seal. Then use a file to get it flush or only ever so slightly proud of the sump. I also degreased everything and added some high temperature silicone sealant all around as a matter of precaution. Some will say it's not necessary but you have now seen for yourselves why I always recommend this rubber seal mod as I gave up on cork long ago. Tighten the sump screws hand tight and allow the silicone to fully cure before final tightening. I even ran a bead of silicone on the outside but again maybe buckles and braces. Then it should be fine.
Regards
Declan

I think thats a great idea about letting the silicon cure before fully tightening. I will cut the rubber seals so they are 1mm higher than the sump gasket. Being rubber, I would have thought they would squeeze tight. Anyway, I will let everyone know how I get on later in the week. Cheers

[David53]

Mine is a 1098cc, but as far as I know, the sumps are the same..

Can anyone confirm this?

[rayofleamington]

the rubber ones can be cut 'flush' with the gasket.
The compression on the rest of the rubber will help spread the rubber out to fit the available 'gap'.
The cork gaskets will compress in a different way to rubber (elastomer if you want to be technically correct, most likely it will be NBR material) - rubber flows more than it compresses (i.e. the volume stays the same but the shape changes), but cork compresses more and isn't good at 'flowing' (i.e. it reduces in volume when compressed)

[swithland]

Brilliant, then that is how i will do it, many thank Ray.

[bmcecosse]

The problem though is - do you have crankcase pressure ? With hot engine - remove the oil filler cap and rev up. Is there a plume of smoke/fume ? The rocker breather is a good thing - but for best effectiveness it needs to be plumbed directly into the carb - and not to the air filter casing where it splatters oily mess over the paper element - clogging it hopelessly.

[swithland]

I dont get any smoke out of the rocker cover when I take the plastic cap off when the engine is hot and is revved. The carb does not have a connection on the side for the rocker cover pipe, so its connected unfortunately to the air filter housing. Although many have said the air filter gets all clogged up, ive been checking mine regularly and that has not been the case.

When the engine was recently reconditioned, I ordered a new carb, but didnt ask for one with the suction connector for the rocker cover pipe as at the time I didnt know about the potential problems of crankcase pressure. Also, the rocker cover on the original engine didnt even have a breather pipe connector on top which I only recently changed to one with a breather !!

Anyway, now I know how to cut the plastic seal, I will give that a go and see if that cures the problem.

I did notice that the cork or cork style seal on the sump cover was flush with the top of the sump and reading about the compression of the cork gaskets suspect the engine reconditioners probably didnt leave the cork gaskets a litte longer when they fitted and trimmed them.

Will let everyone know how I get on.

[David53]

My car is the same. I have the rocker cover outlet connected to the inlet manifold and I don't think crankcase pressure is really an issue. The rear sump cork seal just alllows oil to dribble past and leak. Only 3-4 drops but enough to upset people with nice driveways!

[swithland]

My car is the same. I have the rocker cover outlet connected to the inlet manifold and I don't think crankcase pressure is really an issue. The rear sump cork seal just alllows oil to dribble past and leak. Only 3-4 drops but enough to upset people with nice driveways!

Im expecting a delivery today with a load of bits and bobs so will spend the day tomorrow getting it all sorted. Im not really bothered about the tiny drips of oil, but the Hong Kong Government are and when it comes to MOT time in December they wont be allowing any dribbles.

[David53]

You could do what I do - park just around the corner from the testing station and crawl under and wipe the rear plate and back of sump nice and clean. Then drive in

[swithland]

Thats what I did for its first MOT last December, but I was extremely nervous because they kept her running for a good half hour before they even took a look underneath !!

[swithland]

The rubber seals made no difference, in fact made it worse as it now leaks from the front and the back !! Not a massive amount, but enough to make the carpark floor slimey

Ive just received a tube of Blue Hylomar and am going to give that a go over the weekend. Feels like im not going to be able solve this problem.....

[bmcecosse]

Are you sure it's the sump seals that leak - and not oil running down from above? Could be the scroll at the rear - and the timing case cover seal at the front. Hard to believe the rubber sump seals haven't sorted this out!

[swithland]

Are you sure it's the sump seals that leak - and not oil running down from above? Could be the scroll at the rear - and the timing case cover seal at the front. Hard to believe the rubber sump seals haven't sorted this out!

Ive been under with a torch to have a good look and it is definitely the sump seals. This time, im going to try and flatten out the sump flange that runs around the outside of the sump as it seems that the bolts have indented themselves into that flange. Maybe that is causing the sump to not sit tightly enough against the block ??

[Longdog]

If it is any help I used Loctite 5922 with great success on cork seals.This sealant takes a while to go off so if you spread it in the groove where the gasket locates then as the gasket compresses the sealant will allow the gasket to move as necessary. I "prime" the surfaces of the journals with a coat to aid adhesion and add a generous helping to the gap between the seals and gasket intersections. I also smear this on the gasket. Finally a good helping on the mating surface of the seals and fit to the required torque (6lb/ft) evenly around the sump taking several pulls on the bolts from side to side to pull it into contact.
This sealant also allows easy dismantling in the future and in my experience seals perfectly.

[swithland]

If it is any help I used Loctite 5922 with great success on cork seals.This sealant takes a while to go off so if you spread it in the groove where the gasket locates then as the gasket compresses the sealant will allow the gasket to move as necessary. I "prime" the surfaces of the journals with a coat to aid adhesion and add a generous helping to the gap between the seals and gasket intersections. I also smear this on the gasket. Finally a good helping on the mating surface of the seals and fit to the required torque (6lb/ft) evenly around the sump taking several pulls on the bolts from side to side to pull it into contact.
This sealant also allows easy dismantling in the future and in my experience seals perfectly.

Thanks for this advice. I will need to order some from the UK and have it posted out. In the meantime, im going to give the Blue Hylomar a go on Saturday and see if that makes any difference. I have attempted to reseal this several times without success with all kinds of sealants. I wonder what it is that I am doing wrong ???