17 replies to this topic

[PaddyShepherd]

Hi all.

Noticed a few oil leaks on my mini. One of which is the gear selector (I'm just waiting on the punch tool for that, unless you can recommend alternatives)

However, this second leak is at the bottom of the sump on the passengers side. (I'll be honest I don't really know what to call it) I've taken a picture to show you what I mean. I'm assuming probably a knackered gasket in there maybe? But if so, would the engine need removing to change this?

[jmmini]

I have same leak, however its very slow

[mini danny]

It dpeends where.its leaking from other than the selector and i used a old drill bit to get the roll pin out

[valve bounce]

for that casing bit, check the bolts are nice and tight then wash it off and see what happens

[jaydee]

The leak in the pic could also be from the timing cover. You dont need to take out the engine, and follow valve bounce advice at first.

[PaddyShepherd]

Yeah I will check all the bolts tomorrow. What would be the procedure for the timing cover?

[1984mini25]

What you are better off doing first is hosing off and cleaning that side of the engine so it’s as spotless as possible, then checking a few days later.

As it could be any of… the engine back plate, half moon seal, timing cover, crank pulley seal or a gearbox gasket.

[Cooperman]

If it's the timing cover it's very easy to change that gasket. The mistake is over-tightening the little bolts and splitting the new gasket. I always use a bit of gasket sealant and then just 'nip' the bolts up.

[jaydee]

Its not complex at all, maybe a bit awkward with engine in situ, but nothing really complicated. Plus you can change the timing chain at the same time and do a coolant flush aswell:

Remove the rad, its held by the top bracket and a long bolt below the rad, detach the bottom hose, so you can also flush out coolant and give a clean at the rad at the same time. Remove the fan belt (undoing the alternator adjustement bracket) and the fan. Note that if the fan is not marked 'front' or 'engine side' mark it so you'll be sure to put it in the right way while rifitting all the stuff.
At this point i would also remove the water pump to gain better access, but you can leave it place.
Now you have to lock the engine to stop it cranking while undoing the big crank nut. Best way would be removing the starter motor and locking the flywheel using a U shaped bit of metal in which you drilled a hole to bolt it to the clutch housing. Put it in 1st gear too.
Now remove the big crank nut and the pulley and the zillion bolts that hold the timing cover, carefully putting them over a piece of carton where you can mark their position in the timing cover (the bolts are also different lenghts)
Remove the timing cover, now you can clean it from the residues of the old gasket and sealant, and replace the black oil seal.
At this point would be really worth it to change the timing chain and tensioner (if fitted) and check the timing too (if you have a performace cam fitted).
Now fit the new gasket to the timing cover appling gasket sealant on the timing cover side only. Then smear some gasket sealant over the gasket only on the half bottom side.
Then refit everything.

[Cooperman]

Well explained, jaydee.

[1984mini25]

Apart from when you come to put the cover back on, refit it with 2 or 3 bolts loosely. Then side the pulley onto the end of the crank to centralise the seal and then tighten up the 2 or 3 bolts, Remove the pulley and refit the rest.

[PaddyShepherd]

What you are better off doing first is hosing off and cleaning that side of the engine so it’s as spotless as possible, then checking a few days later.

As it could be any of… the engine back plate, half moon seal, timing cover, crank pulley seal or a gearbox gasket.

I cleaned the bottom of the sump a few days ago. Saturday I believe. Oil gathered where shown in the picture and seems to be the source, and theres some near the selector seal too which I will hopefully be changing on friday. I've been told I can leave the oil in for this and just jack it up at the back, is that right?

Its not complex at all, maybe a bit awkward with engine in situ, but nothing really complicated. Plus you can change the timing chain at the same time and do a coolant flush aswell:

Remove the rad, its held by the top bracket and a long bolt below the rad, detach the bottom hose, so you can also flush out coolant and give a clean at the rad at the same time. Remove the fan belt (undoing the alternator adjustement bracket) and the fan. Note that if the fan is not marked 'front' or 'engine side' mark it so you'll be sure to put it in the right way while rifitting all the stuff.
At this point i would also remove the water pump to gain better access, but you can leave it place.
Now you have to lock the engine to stop it cranking while undoing the big crank nut. Best way would be removing the starter motor and locking the flywheel using a U shaped bit of metal in which you drilled a hole to bolt it to the clutch housing. Put it in 1st gear too.
Now remove the big crank nut and the pulley and the zillion bolts that hold the timing cover, carefully putting them over a piece of carton where you can mark their position in the timing cover (the bolts are also different lenghts)
Remove the timing cover, now you can clean it from the residues of the old gasket and sealant, and replace the black oil seal.
At this point would be really worth it to change the timing chain and tensioner (if fitted) and check the timing too (if you have a performace cam fitted).
Now fit the new gasket to the timing cover appling gasket sealant on the timing cover side only. Then smear some gasket sealant over the gasket only on the half bottom side.
Then refit everything.

Thanks for the advice mate, I will get back once I've checked the other options and ask for more advice if needs be.

[jaydee]

I cleaned the bottom of the sump a few days ago. Saturday I believe. Oil gathered where shown in the picture and seems to be the source, and theres some near the selector seal too which I will hopefully be changing on friday. I've been told I can leave the oil in for this and just jack it up at the back, is that right?

No idea to be honest i've done that with the sump dry..draining the oil is always a good idea when working on those seals, you know a facefull of oil is not very healty...
Jack up by the subframe and put it on jack stands well high so you can move comfortably under the sump and carry a big light with you, will make the job A LOT easier espescially when it comes to refit the dreaded rod change pin.
The worst part will be taking the old rubber seal off, its realy a pain but if no avail theres always a way to bodge it (put the new seal over the old and sit it flush using a deep socket, at least works, but use it as the really last option because the next time you need to change the seals, it will be double the pain)

Get hold of this kit:
http://www.minispare...ls/MSSK050.aspx
Remeber to slide the gaiter over the alloy spacer and the rod a bit.
I have to admit the rubber gaiter didnt last very long on mine but i blame it to the fact i havent fitted the sump guard extension and went out for off-road sessions (how genius am i?)

[tiger99]

You may have a leak at the extension casing which contains the speedo drive, and also gives access to th efinal drive pinion. There is a large gasket between the extension and the main casing, and small gaskets between a little cover plate on the end and the extension casing, and also the speedo drive adaptor. None of these are engine out jobs, just jack up and remove the mount (probably need radiator out), and do what will then be obvious. If you are in doubt, these can be done at the same time as the timing cover gasket and the cranksahft seal, as in each case it is easier to have the radiator out, and doing all the gaskets in that area will not take much longer than doing one.

If it is the half moon gasket, which I have never known to fail although it is certainly possible, It is really an engine out job, although strictly speaking you can avoid undoing driveshafts etc by splitting the engine and leaving the gearbox in the car, if you like awkward jobs. Possible but not usually advisable. I have done it.

But as has been said, you really need to get the area very clean so you can identify the leaks precisely.

If you have the timing cover off, please do fit a new cranksahft seal as well as the gasket, and centre the cover by pushing the oiled pulley into the seal before tightening the cover bolts.

[bmcecosse]

It's almost certainly running down from above - probably the front seal on the timing case. If it is the rubber half-moon seal - then yes -engine out, leaving the box behind. It's easy - and FAR quicker than taking the whole unit out - then splitting it.