Bleed screws/nipples on my Landrover Defender

[Achfary]

Renewed brake pads on my Defender TD5

Brakes need to be bled but the bleed screw/s would appear to be seized.

Have owned this vehicle for 6 years and not attempted to bleed brakes before.

Any advice on bleed screw removal would be much appreciated 

Thanks in advance

[Maverik]

Hello and welcome to the forum.

A common problem. 

if you can get a open ended ring spanner on it and its not slipping on the nut, the give it a good wire brush and get some penetrating oil on it and work it backward and forward, they usually free up with some careful effort.

If it corroded and you've rounded off the nut, I'd recommend you get some new bleed screws ordered and get some mole grips crank them up tight and do the same as you would with the spanner as above, just work the it backwards and forwards until you get a slight bit of movement.

In my experience, the standard bleed screws are pretty poor, they're often a small size that even with a slight amount of corrosion then cause any attempt to undo just rounds off the hex on them, I put stainless ones in the last set of calipers I installed got fed up of this issue.

 

Mav

[landroversforever]

If you've still got the hex in reasonable shape, a six sided socket is your best bet. If not, the mole grips or similar as above.

 

[cackshifter]

A few taps with a light hammer on the end help break the corrosion if the nipple is beyond re-use, and heat will also help ( but don't overdo it)

[Sigi_H]

Soak it over night with WD40. Then bounce the nipple with a hammer and use a six sided socket to remove it. Then use a new nipple. If you do not bounce it, it may breakaway.

[Achfary]

Thanks for the welcome and advice Maverik.

I will give this a go,think I will order new bleed screws as a precaution 

[Achfary]

14 hours ago, cackshifter said:

A few taps with a light hammer on the end help break the corrosion if the nipple is beyond re-use, and heat will also help ( but don't overdo it)

Thanks cackshifter,advice appreciated 

[Achfary]

14 hours ago, Sigi_H said:

Soak it over night with WD40. Then bounce the nipple with a hammer and use a six sided socket to remove it. Then use a new nipple. If you do not bounce it, it may breakaway.

Thanks Sigi,did try soaking with WD40 already

A friend also suggested Plusgas,so will try this

[Sigi_H]

Bouncing also works with seized screws. The difference to the bleeder is that the latter is probably damaged after bouncing. The bouncing will loosen oxidation in the thread. One hard bounce is better than a few soft ones. Soaking with WD40 is only additional.

[Qhriss]

Small nozzle on yr Oxy Acetylene torch , get it red hot- it will come out . K

[Paddy]

I never found WD that good as a releasing fluid.  After a lifetime in oil refineries with plant in extreme weather, temp and pressures, “Penol” was the go to releasing agent.  You might want to try it next time.

[RedLineMike]

8 minutes ago, Paddy said:

I never found WD that good as a releasing fluid.  After a lifetime in oil refineries with plant in extreme weather, temp and pressures, “Penol” was the go to releasing agent.  You might want to try it next time.

agree with this, we use wd40 at work (refinery) & its no good, found Rocol Penetrating spray is about the best ive used

 

On 12/3/2020 at 12:54 PM, Qhriss said:

Small nozzle on yr Oxy Acetylene torch , get it red hot- it will come out . K

id be wary about doing this, ive heated up a brake fitting to release it & ended up blowing the flexi house out the ferrule

[tychoS]

3 hours ago, Paddy said:

I never found WD that good as a releasing fluid.  After a lifetime in oil refineries with plant in extreme weather, temp and pressures, “Penol” was the go to releasing agent.  You might want to try it next time.

I agree. WD40 is a poor choice for undoing rusty threads.

See what the professionals in your area are using, and try to shop where they do.

[tychoS]

On 12/3/2020 at 1:54 PM, Qhriss said:

Small nozzle on yr Oxy Acetylene torch , get it red hot- it will come out . K

It will most likely come out, but at what price?

You risk ruining the seals and having to refurbish the caliber/brake cylinder.

If you choose to use heat, do empty the brake caliber/cylinder of brakefluid first and leave it open while applying heat. Preferably remove it from the vehicle before applying heat. That means undo the brake line first. 

If the brakeline is too far stuck to undo without heat, then most likely you are in for a full refurbishment of the caliber/cylinder anyway.

[western]

I use PlusGas releasing spray, its works fine for LR jobs. 

 

[Qhriss]

On 12/4/2020 at 2:41 PM, RedLineMike said:

agree with this, we use wd40 at work (refinery) & its no good, found Rocol Penetrating spray is about the best ive used

 

id be wary about doing this, ive heated up a brake fitting to release it & ended up blowing the flexi house out the ferrule

Oh my word , I meant just a tiny flame , with appropriate guarding , aluminium body cylinders disipate heat quick, so seals wont cook. As ever , try at yr own risk - but successful for me K

[Troll Hunter]

On 12/4/2020 at 6:31 AM, Paddy said:

I never found WD that good as a releasing fluid.  After a lifetime in oil refineries with plant in extreme weather, temp and pressures, “Penol” was the go to releasing agent.  You might want to try it next time.

Yes, WD40 is a moisture dispersant primarily for use on electrical circuits, not for freeing seized threads.  It happens to have relatively god penetrative properties, but there are much better alternatives.  I use a home made 50/50 mix of acetone and ATF.  Very effective.  Remember to shake it up each time before you use it since it separates into two phases.

Mike

[David Sparkes]

On 12/4/2020 at 5:53 PM, tychoS said:

I agree. WD40 is a poor choice for undoing rusty threads.

See what the professionals in your area are using, and try to shop where they do.

For people 'on the other side of the pond', Kroil seems to be the best of the penetrating oils.
See this stateside comparison, while it includes WD40 it doesn't include Plus-gas, probably because it has limited availability in that market.

For those of us in the UK, I have been guided by Bad Obsession Motorsport, specifically their YouTube videos on 'Escargot'.
In one episode (I think 1 or 2) they were dismantling parts from the Ford lorry chassis, parts which had been in place for many years and exposed to road dirt and spray (clear similarities to our LR experiences).
They made positive comments about whatever release spray they were using, without actually publicising it, and always having a hand over the signwriting on the bottle. Eventually a bottle was exposed in the background while they were doing activity in the foreground.

This product turned out to be XCP, and here is a comparison funded by the makers, but run by an independent organisation. There is some overlap with the stateside comparison (PB Blaster and WD40) but this one also also includes Plusgas.
The review also includes how they set up the test.

I have spent money on the Green One product, but ironically have not had occasion to use it.

I should perhaps point out my scepticism about 'all' these penetrants, although I've always made sure I have Plusgas in stock. Whenever I have found a really corroded nut, despite using Plusgas, spray or pouring version, and leaving some time, when the nut is loosened most of the thread that was under the nut is dry, the oil can been seen to have only penetrated one or two turns of the thread.

I have come to believe that the real benefit of these very thin oils is to 'penetrate' the dirt and rust of any exposed thread, and thus to lubricate the nut as it winds over these exposed threads. If accesible I always wire brush exposed thread before applying any liquid. If left unlubricated I suspect most of us have found instances of the nut initially turning, but then jamming as it is unwound. The initial loosening is down to sufficient torque being applied to the nut, or heat!

My experiences were formed while I didn't have access to powered wrenches, Air or Battery.

Regards.

[Sigi_H]

6 hours ago, Troll Hunter said:

50/50 mix of acetone and ATF

There is only one argument speaking for WD40: Its a ready to buy spray. I spray it on, wait for a night and 80% will move. If it doesn't use the mentioned