Persistent Sump Leak

[eeyore]

So, my '97 300tdi disco has been leaking around the sump join in multiple places for a little while. Decided to do something about while I was changing the engine oil anyway. I bought some Permatex 'The Right Stuff' (@ $48 :eek:), removed the sump, cleaned the old gasket joiner off, put a good solid bead on it and was careful to go fully around each bolt hole, refitted it and torqued the bolts to spec. Cleaned all the old oil off and checked it again a week later. Definitely improved, but still leaking significantly along the back edge of the sump:mad:.

So, what did I do wrong? The only things I can think of are that either the sump isn't flat - although I would have thought that the nature of the gasket joiner should mean it is able to compensate for a little warping at least, or that the bolt holes in the block aren't blind and that I need to put some gasket goo on on the bolts before refitting to stop oil leaking past the threads?

TIA :)

[gazby]

Are you sure that it is the sump gasket? I have also a '97 300Tdi and it exhibits the same little problem oil leak, and believe it or not that is the sole indication of an oil leak anywhere beneath the car at 180,000 kls. The oil was slightly smearing on the right side of the sump and a little bit on the front diff/driveshaft. I thought sump gasket, until the last oil change, when I climbed under the car with the engine running to check the filter joint, I looked up and saw a small amount of oil being spattered out of a joint on the brake booster vacuum pump on the right side of the engine block. There is a riveted joint there and as the parts appear to be plastic it looks like the rivets have loosened allowing a small amount of oil to constantly escape while the engine is running and pump operating. The brakes are fine, as a matter of fact much better than my previous Disco. How to fix the leak at the pump............I will have to look in the forum. Hope this may help. Cheers.

[BigJon]

Probably the rear main seal and/or the T seals leaking. Either engine or gearbox out to repair.

[eeyore]

Thanks, good suggestion and I wish that was the problem. Unfortunately, I've already done the 'upgrade' on the vacuum pump (rivets replaced with nut & bolts, new gaskets) and that's one component that _isn't_ leaking! Worth doing the fix on the pump too; I found I had improved pedal feel and bite under heavy braking afterward, rather than the wooden feel it had before.

[eeyore]

Thanks for the suggestions guys. I've done the 'upgrade' on the vacuum pump (rivets replaced with nuts and bolts, new gaskets) and I'm certain that is one component that _isn't_ leaking:D. BTW gazby, I'd recommend carrying out this straightforward fix; I found that it improved both pedal feel and bite under heavy braking on my Disco.

It shouldn't be the real main seal either, since I paid to have that replaced when the clutch was done about 20K km ago - guess that doesn't guarantee anything. Not sure about the TC though. If it were the TC, would the oil leak down the outside of the bellhousing and / or inside the BH and out through the breather hole? If it were the latter, perhaps I could put the wading plug in, clean up the oil, then see if I get a leak?

[langy]

When Mr BJ say t-seals he isn't referring to the transfer, but the seals on the #5 main bearing cap - they are a T in shape- and they get hard and let oil run down between the engine block and transmission adaptor. They wouldn't have been changed when the clutch was done. However, I dissent with Mr BJ as to how to repair it: Sway bar down, sump off, cap off and new t-seals. There have been a few threads - search for "300tdi t-seals". It's reasonably easy.

[Nomad9]

Hi eeyore,
I had similar problem, you are best washing off the sump as best you can with a degreaser and then watching where it comes from. I used the Toyota black sealant, seal packing (Black) it is called, part number 00826-00080-A. I'm not a great fan of the Yotas, but this stuff is second to none, and it ain't $68 a tube. Since putting the sump back on it has been as dry as a bone. One thing with the Yota sealant is it has to be assembled within five minutes of application which means to have to be well organised.
Hope this helps.

[eeyore]

Ah, didn't read Mr BJ's post properly. Just saw main seal and 't' and jumped to the wrong conclusion. Thanks for clarifying that langy. Your description of the leak point pretty much exactly matches where I think the oil is coming from too. I'll do a search as you suggest.

Since I'll have the sump off anyway, I'll take your advice too Nomad9 and try some of the Toyota sealant - should have all my bases covered then :)

Thanks to all for your help.

[steveG]

In case you're not already doing it, give the sump and block faces a good wipe over with thinners before you put the sealant on too.

Steve

[Rezley]

How'd you go eeyore?

[eeyore]

Resurrecting an old post here, but thanks to everyone for their help. I've replaced the t-seals and no more leaks; very happy. I used some gasket sealant on the t-seals which both held them in place - sort of - and helped them slide - sort of - as I put the bearing cap back in. It was a bit messy and took a few goes but got there eventually. I bought four of the seals which was useful because I ripped one on the first attempt.

Just a couple of observations from my experience doing this repair. First, I found removing the bearing cap by hand impossible, despite following a couple of techniques I found on the web. In the end, I made up a simple extractor tool from a length of steel bar and HT M8 threaded rod. The cap came out easily using this. Second, the ends of the seals stretched quite a bit when I but the cap back in, protruding beyond the cap by probably 10mm. This is a lot more than the RAVE illustration suggests. I was actually worried that they had torn going in but 2K km later and no leaks, so I assume not. I did wait a couple of hours before I trimmed them to give them time to shrink back, although I can't say I noticed much change. Finally, I did the job without the little guides - as do most people I guess - but if I were to do it again, I would be tempted to make up some up out a little bit of plastic chopping board, just to ease the aggravation.

Anyhow, not a difficult job, just requires a bit of patience and some deep breaths when putting the cap and seals back in - especially when you drop the bearing cap on your nose on the fourth attempt at sliding it back in :mad:

[Tank]

Resurrecting an old post here, but thanks to everyone for their help. I've replaced the t-seals and no more leaks; very happy. I used some gasket sealant on the t-seals which both held them in place - sort of - and helped them slide - sort of - as I put the bearing cap back in. It was a bit messy and took a few goes but got there eventually. I bought four of the seals which was useful because I ripped one on the first attempt.

Just a couple of observations from my experience doing this repair. First, I found removing the bearing cap by hand impossible, despite following a couple of techniques I found on the web. In the end, I made up a simple extractor tool from a length of steel bar and HT M8 threaded rod. The cap came out easily using this. Second, the ends of the seals stretched quite a bit when I but the cap back in, protruding beyond the cap by probably 10mm. This is a lot more than the RAVE illustration suggests. I was actually worried that they had torn going in but 2K km later and no leaks, so I assume not. I did wait a couple of hours before I trimmed them to give them time to shrink back, although I can't say I noticed much change. Finally, I did the job without the little guides - as do most people I guess - but if I were to do it again, I would be tempted to make up some up out a little bit of plastic chopping board, just to ease the aggravation.

Anyhow, not a difficult job, just requires a bit of patience and some deep breaths when putting the cap and seals back in - especially when you drop the bearing cap on your nose on the fourth attempt at sliding it back in :mad:
Ouch!!, thanks for the reply, Regards Frank.

[Rezley]

Good news in the end. Cheers eeyore.

[nice1guv]

Hey eeyore, what sealant did you end up using on the sump?

[DiscoMick]

Thanks for the information. I think I have a similar leak, but haven't pinpointed where its coming from. I'll have to wash it and watch.

[Nomad9]

Hi Eeyore,
I've done a couple of engines without the small blocks, and agree with you this is quite a difficult job. I've now made a couple of small blocks up and they work a treat, make the job so much easier, and you feel with confidence that the job is done as good as it can be done. For the time it takes to make the blocks up you would easily waste that much of your life doing the job again when and if they leak.