Wheeping diff plug

[jedwards]

Hi everyone,
I have a whipping diff plug and want to know if its safe to apply some teflon or silicone "sealer" to the threads to stop it leaking.
The brass plug is new, and the copper washer is new, but just wheeps Diff Oil, which upsets the boss.

Also, is it permissible to apply any sealer to the coupling threads on the brake system? I have a slow leak from the Master cylinder reservoir. I've replaced the pipe, but it still leaks.

thanks in advance,

regards
Jeff in sunny Perth

[JDNSW]

There are better sealants than the ones you suggest for the diff plug, but any will work, although they should not be needed. Perhaps the washer needs annealing.

Sealant of any kind should not be used on brake junctions. If it leaks it is something wrong with the joint, either damaged joining bits, damaged thread, wrong type of flare etc.

[p38arover]

I use No. 3 Aviation Gasket Sealant on the threads of drain plugs. That stops them weeping (but not whipping or wheeping though).

182982

[Tins]

(but not whipping or wheeping though).

You need antihistamines for those.

[1950landy]

I use Loctite 569 or 577 hydraulic thread sealant on all the plugs & pipe fittings on my 80"

[whitehillbilly64]

I use Loctite 515, on the drain plugs.

whitehillbilly

[gromit]

I don't use anything but anneal the copper washer.
It seems that most sealing washers are supplied dead hard and aren't suitable for sealing. If you re-use a washer they have usually hardened so anneal & re-use.
I don't think I've ever changed the sealing washer on my Defender sump plug despite multiple oil changes.

Colin

[Tins]

I don't use anything but anneal the copper washer.
It seems that most sealing washers are supplied dead hard and aren't suitable for sealing. If you re-use a washer they have usually hardened so anneal & re-use.
I don't think I've ever changed the sealing washer on my Defender sump plug despite multiple oil changes.

Colin

One of the problems these days when replacing the "copper" washer is that they don't pass the magnet test. Annealing the old one makes perfect sense.

[LR1953]

Jeff, for your weeping diff plug, (assuming it's the drain plug) I'd suggest Loctite 567 Master Pipe Sealant, applied to scrupulously clean threads on the plug. The threads on the diff housing will also need to be absolutely clean and dry. Have a look at Loctite's website to see the specs and applications for the various grades mentioned on this thread.
Cheers, Rob S

[jedwards]

Many thanks Gentlemen,
Advice greatly appreciated. I'll follow your advice and get it sorted over the weekend.
nest wishes
Jeff

[WayneHall]

I don't use anything but anneal the copper washer.
It seems that most sealing washers are supplied dead hard and aren't suitable for sealing. If you re-use a washer they have usually hardened so anneal & re-use.
I don't think I've ever changed the sealing washer on my Defender sump plug despite multiple oil changes.

Colin

Hi, can I ask a naïve/stupid question - what process do you actually use to anneal the washer, i.e. heat with what? Cool how - over what time period? etc....

I've never done it before.

Thanks
Wayne

[p38arover]

^^ I heat them up with a gas torch (but one could use a gas stove) until they are red then plunging them into water.

Note: for a lot of diff plugs, there is no gasket/washer and no way to add one, especially if they use a plug like this (pic from All Four x 4 Spares):

183005


Jeff, for your weeping diff plug, (assuming it's the drain plug) I'd suggest Loctite 567 Master Pipe Sealant, applied to scrupulously clean threads on the plug. The threads on the diff housing will also need to be absolutely clean and dry.

While this may be the ideal, it's virtually impossible the get the housing threads oil free after one has topped up the oil. I just wipe the threads, apply Aviation Sealent No.3 to the plug threads and put it in. Works like a charm.

[gromit]

Hi, can I ask a naïve/stupid question - what process do you actually use to anneal the washer, i.e. heat with what? Cool how - over what time period? etc....

I've never done it before.

Thanks
Wayne


No such thing as a stupid question....

Hold the washer on a piece of wire and heat with a blowtorch until cherry red, I tend to keep it cherry red for a few seconds.
You can then either let it cool down or normally I quench in water as it removes any scale.

Some of the gearbox/diff washers are rolled copper, these hold a bit of oil so it gets a bit smokey but once burnt off and cherry red quenching in water makes them re-usable.

I've done this with brake copper washers including the large one at the rear of early master cylinders, never had a problem.

As mentioned earlier, a lot of suppliers sell copper washers in a dead hard state making them next to useless in a sealing application.

Colin

[WayneHall]

Thanks Colin and Ron

I've been upskilled on Saturday morning before I've even had my first cup of tea.

Cheers
Wayne

[Tins]

^^ I heat them up with a gas torch (but one could use a gas stove) until they are red then plunging them into water.



I believe the correct expression is "cherry red". Well, that's what I was taught. I could never determine which variety of cherry was being referred to, nor how ripe.

[Tins]

No such thing as a stupid question....

X2.




As mentioned earlier, a lot of suppliers sell copper washers in a dead hard state making them next to useless in a sealing application.

Colin

Many of them are not copper at all, but recycled fridges or something with a thin copper coating sprayed on. I always check with a magnet. It's often hard to know where a part has actually come from these days.

[Tins]

I've been upskilled on Saturday morning before I've even had my first cup of tea.



And without, so far, any arguments. Welcome to AULRO.

[trout1105]

Have you considered replacing the sump plug?, The thread may be worn out/stretched on the old one.

[p38arover]

I believe the correct expression is "cherry red". Well, that's what I was taught. I could never determine which variety of cherry was being referred to, nor how ripe.

Yes, I meant to write that but it was subsequently mentioned so I didn’t worry about amending it.

I just make it bright red as most cherries we get are quite dark. :)

[Tins]

Yes, I meant to write that but it was subsequently mentioned so I didn’t worry about amending it.

I just make it bright red as most cherries we get are quite dark. :)

Yes. I responded to you before I read Colin's comment.

If it must be described by a fruit, maybe the colour of a ripe mango gets close...

[gromit]

Just replaced the washer on the drain plug from a Station Wagon tank.
It was a solid copper washer rather than a composite or folded one. It took a while to get cherry red and still seemed to be fairly hard after quenching, annealed a second time keeping it red for longer.
Fitted and no petrol leaks.

Colin

[5380]

Many thanks Gentlemen,
Advice greatly appreciated. I'll follow your advice and get it sorted over the weekend.
nest wishes
Jeff

Jeff,

LR1953 hit the nail on the head. Loctite 567 is THE thread sealent for drain, filler and level plugs etc. It also stops them from coming loose, but they are still easily undone with standard tools. The other sealants mentioned also work, but were designed to be used as flange sealants. The leaking brake pipe probably has a damaged flare. I had the same problem myself. New steel Bundy tube with the appropriate double flare should cure the problem, unless the seat in the cylinder is damaged. There are fibre washers on the nipple in the base of the reservoir that can leak also. Good luck!

Mike (5380)

[1950landy]

Jeff,

LR1953 hit the nail on the head. Loctite 567 is THE thread sealent for drain, filler and level plugs etc. It also stops them from coming loose, but they are still easily undone with standard tools. The other sealants mentioned also work, but were designed to be used as flange sealants. The leaking brake pipe probably has a damaged flare. I had the same problem myself. New steel Bundy tube with the appropriate double flare should cure the problem, unless the seat in the cylinder is damaged. There are fibre washers on the nipple in the base of the reservoir that can leak also. Good luck!

Mike (5380)

On my 80" I found cracked seats in the cylinders & one was so bad it had completely come out.