Torqueing Lubricated Head Bolts with a dry spec.

[ducked]

Originally Posted by buick8791

An questions(maybe an wrong issue on this thread, sorry) regarding WD-40 used to the rubber parts in the car, for instance the brake caliber rubber o-rings related to the caliber sliding parts:

Is that stuff swelling the rubber parts some how?

BR,

buick8791

Yeh, I'd say you are a bit off topic, but since we are here, I'd say you shouldn't use it, cos I THINK its an organic solvent base with some wax (something like white spirit, though I dunno exactly what it is) and will likely attack rubber.


My routine is


Ignore the prevailing Internyet advice to blow the pistons out with compressed air, spectacularly daft when you have a brake pedal designed for the job.


(TBH it took me a day or two of messing about for this to dawn on me)

Clean - up pistons and bores with aluminium foil, a gentle conformable abrasive with an anti-corrosion effect


Calipers (and especially the slider surfaces under the stainless steel clips) abrade with a flattened beer can disk in a power drill, finally using sunflower oil as a binder, so you get an aluminium paint in intimate contact with the steel.


Dry lube only (or nothing) on the stainless clip surfaces and pad ears. I rub the clips with a soft "chippy" carpenters flat pencil, and wrap PTFE tape around the pad ears.


Caliper pins wrap with PTFE tape and apply silicone grease (bought in Japan).



I also have some Red Rubber grease I bought in Japan, and some fantastically expensive Bendix Ceramlube I bought in Australia (you can't get anything in Taiwan) but the PTFE/silicone combo seems to work well so I havn't used them.

[ducked]

I had to remove the head again due to me following the advice in the manual to lock the cam sprocket with a screwdriver. This was quite clearly never going to work, and sho nuf the cam sprocket shifted and jammed.


(I'm quite impressed by the utter bollocks in the manual in this context. The suggestions for locking the crankshaft were similarly reality defying.)



I used the torque-to-turn-translation (tturnslation?) method for aluslip lubricated bolts as before.


Recorded torque values are higher this time, perhaps due to the thinning out of the aluslip and/or compression of the gasket.


https://forumosauploads-12829.kxcdn....27a93c15b0.png



https://forumosauploads-12829.kxcdn....dd82552d7b.png



If I have to do it again (hope not) I'll top up the aluslip a bit, and maybe use some copper spray on the gasket.


Bolt 2 (In the tightening sequence, B3 in position) doesnt gain any torque between the penultimate and final tightening, which seems odd, but happened last time. so it also seems consistent.


I'd guess this is due to the turning of bolt 1 unloading it.

[ducked]

The increase in torque does seem to support the “received wisdom” that you shouldn’t re-use head gaskets (though I have re used one on an 1800 BMC B series with no issues, and you have to re-use at least once to use this torque translation technique).


Probably contra-indicates installing this gasket again, or indicates reverting to a torque limited procedure if I did re-use it.


If I have to take the head off again, I might re-use the original gasket, (which has only been installed once, though of course its been in the engine for 12 years) or maybe even break down and buy yet another head gasket.

[buick8791]

Originally Posted by ducked

Yeh, I'd say you are a bit off topic, but since we are here, I'd say you shouldn't use it, cos I THINK its an organic solvent base with some wax (something like white spirit, though I dunno exactly what it is) and will likely attack rubber.


My routine is


Ignore the prevailing Internyet advice to blow the pistons out with compressed air, spectacularly daft when you have a brake pedal designed for the job.


(TBH it took me a day or two of messing about for this to dawn on me)

Clean - up pistons and bores with aluminium foil, a gentle conformable abrasive with an anti-corrosion effect


Calipers (and especially the slider surfaces under the stainless steel clips) abrade with a flattened beer can disk in a power drill, finally using sunflower oil as a binder, so you get an aluminium paint in intimate contact with the steel.


Dry lube only (or nothing) on the stainless clip surfaces and pad ears. I rub the clips with a soft "chippy" carpenters flat pencil, and wrap PTFE tape around the pad ears.


Caliper pins wrap with PTFE tape and apply silicone grease (bought in Japan).



I also have some Red Rubber grease I bought in Japan, and some fantastically expensive Bendix Ceramlube I bought in Australia (you can't get anything in Taiwan) but the PTFE/silicone combo seems to work well so I havn't used them.

Thank you for very good information! I have used WD40 for cleaning the caliber eyes where are the rubber o-rings for the sliding parts.

I stop to use the wd for all caliber service and using only the grease intended for lubing and doing the the service as you wrote(not using the grease to some parts).

I have that grease in my shelf, was it CRC brake lube grease...


Thanks for all,

Buick8791

[ducked]

I did wonder if there was a risk of the PTFE breaking down under extreme heat and forming fluoric acid, which is nasty stuff, and had just about decided not to use it any more...but then I came across some Volvo brake grease with added PTFE on the Internyet, so I decided not to worry about it.


If its good enough for the Chinese...

[RidingOnRailz]

Originally Posted by ducked

I did wonder if there was a risk of the PTFE breaking down under extreme
heat and forming fluoric acid, which is nasty stuff, and had just about decided
not to use it any more...but then I came across some Volvo brake grease with
added PTFE on the Internyet, so I decided not to worry about it.


If its good enough for the Chinese...

In applications calling for lubrication, I would use a proper lubricant, silicone-base or otherwise. WD40 is primarily a cleaner, a "loosen-upper", not meant for longterm lubrication and wear mitigation.

Unfortunately, the general public has difficulty making this distinction.

[ducked]

Originally Posted by RidingOnRailz

In applications calling for lubrication, I would use a proper lubricant, silicone-base or otherwise. WD40 is primarily a cleaner, a "loosen-upper", not meant for longterm lubrication and wear mitigation.

Unfortunately, the general public has difficulty making this distinction.

Not sure why this is a reply to my post above, since that post does not mention WD40.

It mentions, and I recommend, PTFE tape (sold as a thread sealer and thread lubricant, very widely available, even in Taiwan, and very cheap) in combination with silicone grease, (which was sold to me as a brake lubricant in a motorcycle shop in Rinko, Japan. You cant get anything in Taiwan)

This combination appears to work very well, as it should, since the PTFE tape wrap on the brake pins cannot be displaced by lateral pressure to allow metal-to-metal contact.

I earlier suggested to the enquirer that he shouldn't use WD40.

[ducked]

The issue here, with brakes, (and the issue raised by the enquirer) is rubber compatability.

Many, in fact probably MOST "proper lubricants" are not rubber compatible, because they have a mineral oil base, as does WD40, though it isn't a very good lubricant.

You need to use rubber compatible lubricants. These might be formulated with silicone oils or castor oil (as in the trad. "red rubber grease" originally from Castrol) and some of them have high solid lubricant content, such as PTFE or ceramics.

Anti-seize (usually with copper or aluminium solids) is often recommended BUT it usually has a mineral oil base so might attack rubber long term.

[ducked]

Originally Posted by RidingOnRailz

You had to do all that experimentation after three... four?.. others on here told you it wasn't necessary?

Of course in general I'd agree that torquing itself isn't necessary, because I seldom use one, but for some things I feel I should.


An alternative in such cases would be to mark the original angular fastner position (too late, didn't think of it) and simply restore it, a turn-of-the-nut method without the need to translate from a torque spec.


www.youtube.com/watch?v=Qs0Kktf-2Uk


Here's yon Hubnut geezer doing essentially this (about 3 minutes in) with a crankshaft pulley bolt.


This does involve the assumption that it wasn't too badly wrong in the first place, but unless you have a blown head gasket, that's probably reasonable.



Too late to do that now with cam sprocket bolt on the front of the engine, since its already off, so I feel I need to apply a torque spec.



My Torque wrench is a cheapo torsion beam type. Not very precise but they are more robust than the “clicky” type, which is why I brought it back from the Yook. Cant get them in Taiwan, according to the Ktown tool shops.


There isn’t clearance to use it on any bolts on the front end of the engine when its in the car, apart from the crankshaft pulley bolt, which is accessible through a port in the wheel well. I cant get a ratchet or a breaker bar on them either so its likely any torque wrench won’t fit.


IOW there probably isn’t a “right tool” for the job


I have to use ring or open-ended spanners on these other bolts, but in principle one could apply a measured force to these with a calibrated spring, giving a torquing capability.


I’m using the luggage scale method outlined here, except I dont have a (working) luggage scale.


engineeringtoolbox.comImprovised Torque Wrench





Crude substitute is half a bike inner tube, cut ends knotted together, with a few turns of Norfolk whipping bootlace above the knot, finished in a reef knot. Shorter loose end is tied to the spanner, longer gets used to measure (and limit) the applied tension. Steel tube through inner tube loop forms T-handle for the pull.


Calibrated by hanging a jerrycan from it and filling with water. (1L water taken as 1kg.) supplemented with 2 X1.9kg iron weights. Not VERY linear (deviations seem to be after loading up the iron) but probably close enough.


forumosauploads-12829.kxcdn.com/original/3X/4/0/40...g
forumosauploads-12829.kxcdn.com/original/3X/4/4/44...g
forumosauploads-12829.kxcdn.com/original/3X/4/4/44...g

Torque = Force X length =mgL
Torque spec. for cam pulley bolt 40nm. Ring spanner 0.22m long ring to ring
m =40/(9.8X0.22) =18.55kg


from above regression line eqn, length for this mass =1.65x18.55+25.13 =55,73cms


Snags? (apart from maybe getting the arithmetic wrong)


(a) If that spanner comes off it'll likely whack the operator pretty hard. Should probably give it a tether.


(b) A “clicky” torque wrench stops applying torque as soon as the spring pressure is exceeded. With this the operator has to stop applying torque, as with the torsion beam type. Likely both clicky and these are affected by operator technique, but to different extents.

[buick8791]

Originally Posted by ducked

The issue here, with brakes, (and the issue raised by the enquirer) is rubber compatability.

Many, in fact probably MOST "proper lubricants" are not rubber compatible, because they have a mineral oil base, as does WD40, though it isn't a very good lubricant.

You need to use rubber compatible lubricants. These might be formulated with silicone oils or castor oil (as in the trad. "red rubber grease" originally from Castrol) and some of them have high solid lubricant content, such as PTFE or ceramics.

Anti-seize (usually with copper or aluminium solids) is often recommended BUT it usually has a mineral oil base so might attack rubber long term.

Thanks for very good information to all to when servicing the brake calibers.

So, I haven´t used WD for final lubing, only for cleaning the caliber fastening bolt holes with the spray and after that the CRC brake lube inside to the bolt holes. Maybe this lube is not good for the o-rings inside the the holes in the question. I have on my shelf also the silicone lube/grease, if it is better than CRC brake lube/grase(what is it containing really), will see after some examination....


Thanks for all!

BR, buick8791