Thread: Oil leaking into handbrake drum - can't seem to cure it!

When I was removing my transfer case off my gearbox the other week even though I had drained both I lost a lot if oil out of the box. It wasn't until I had the extension housing out I saw why.

Evidently a bolt too long had cracked the cast thread. I chucked a helicoil in and a bunch of sealant. Not a transfer case but it could happen.

Going from memory a few years back when I rebuilt mine, but IIRC that scupper is designed in such a way that oil leaking out of the seal should drain externally - and not end up in the drum.
I recall there is an area that has to have sealant to seal against the case or handbrake backplate (don't recall which), but also an area that shouldn't have sealant so that the scupper catches the oil but allows it to drain out externally - not into the drum
Hopefully that makes some sense. I don't recall if the sealing detail is made clear in the manual or if it was one of the tips I got from Brian (Bearman) at the time.
There shouldn't be oil leaking anyway - but if I'm correct about the scupper then either its not fitted correctly, OR, its not coming out of the seal.

I can never remember which way the typical oil migration between g'box and transfer goes, but is there a chance you've got that issue and the transfer ending up overfull? I'd think it would be obvious when you remove the filler plug so its a quick check to do.

Notwithstanding that you're at the end of your rope with it (I read your other thread), I think the logical way forward is to pull the propshaft/drum, degrease the hell out of it, sort out the oil on the brake shoes (soaking the shoes in petrol for a couple of days then letting the petrol evaporate well before giving them a tickle with blow torch to burn out the oil worked well for me - a bit of flame won't hurt them), put it back together and take it for a drive for 20 mins or so.
Home again, pull the shaft/drum and check for any sign of leakage. Dust with a bit of coloured chalk dust if there's nothing obvious as the chalk will stick and darken when it hits oil. You can sand a bit of chalk to make your own powder or buy a container of it from Bunnings chalk powder.
Or use Blknight's dye method if you've got access to some

If its still looking clean at that point then drive it for another few days and inspect again. Key is to find it when there's the start of the leak so you can find the origin. No point leaving it until the oil is everywhere.
If its gone from squeaky clean to handbrake not working in a month then I reckon you'll probably see some sign of it after the first drive.

Steve

Originally Posted by steveG

Going from memory a few years back when I rebuilt mine, but IIRC that scupper is designed in such a way that oil leaking out of the seal should drain externally - and not end up in the drum.
I recall there is an area that has to have sealant to seal against the case or handbrake backplate (don't recall which), but also an area that shouldn't have sealant so that the scupper catches the oil but allows it to drain out externally - not into the drum
Hopefully that makes some sense. I don't recall if the sealing detail is made clear in the manual or if it was one of the tips I got from Brian (Bearman) at the time.
There shouldn't be oil leaking anyway - but if I'm correct about the scupper then either its not fitted correctly, OR, its not coming out of the seal.

I can never remember which way the typical oil migration between g'box and transfer goes, but is there a chance you've got that issue and the transfer ending up overfull? I'd think it would be obvious when you remove the filler plug so its a quick check to do.

Notwithstanding that you're at the end of your rope with it (I read your other thread), I think the logical way forward is to pull the propshaft/drum, degrease the hell out of it, sort out the oil on the brake shoes (soaking the shoes in petrol for a couple of days then letting the petrol evaporate well before giving them a tickle with blow torch to burn out the oil worked well for me - a bit of flame won't hurt them), put it back together and take it for a drive for 20 mins or so.
Home again, pull the shaft/drum and check for any sign of leakage. Dust with a bit of coloured chalk dust if there's nothing obvious as the chalk will stick and darken when it hits oil. You can sand a bit of chalk to make your own powder or buy a container of it from Bunnings chalk powder.
Or use Blknight's dye method if you've got access to some

If its still looking clean at that point then drive it for another few days and inspect again. Key is to find it when there's the start of the leak so you can find the origin. No point leaving it until the oil is everywhere.
If its gone from squeaky clean to handbrake not working in a month then I reckon you'll probably see some sign of it after the first drive.

Steve

There is a sort of drain path that you need to be careful not to block (and I have been careful with it), but as you say, with new seals I shouldn't have oil running out of the thing. On the oil migration issue, I think mine may have had a problem with it in the past but it now has a balance tube. Also, the last two times I pulled it apart I checked the oil level first and it was fine.

I will pull it all apart again and see if I can figure out where it's leaking from. I like the chalk idea - easier for me to get my hands on than dye. I'm not even that interested in fixing it anymore - I am just curious as to where it could be leaking from.

Originally Posted by Dave_S

I will pull it all apart again and see if I can figure out where it's leaking from. I like the chalk idea - easier for me to get my hands on than dye. I'm not even that interested in fixing it anymore - I am just curious as to where it could be leaking from.

Dave, Can't believe you are still having this problem. Yes firstly you have to find out where it is leaking from and we can then work out a fix for it.