Bypass Stub in Cylinder Head - how to get it out

[gtt1951]

I have another possible problem. The bypass stub on my cylinder head (see below)[frame][/frame]
could do with replacing. It is quite corroded and no-longer has any usable slots.
I've tried BMC's preferred method of removal (loads of heat, after treating with any freeing agent), but cannot get a good purchase on it. The shaft is too weak and the rim (you can see the nick I created with my Mole-grip) doesn't afford much surface area to grip.
Any suggestions on removal, or do I just leave it and hope it doesn't totally rot away?

[bmcecosse]

I would leave well alone.

[chrisryder]

I had the same problem, well even worse actually. No chance of a hose ever sealing on there!
[frame][/frame]

Ended up welding a T bar in:
[frame][/frame]

The heat helped free it, then a bit of oil to soak down the threads... and voila!
[frame][/frame]

Easiest way to unscrew it was to turn it upside down and hold the 'handle' in a vice, and turn the head.

[MarkyB]

I'm with Roy on this leave well alone.
Decent anti-freeze should stop it getting any worse.

[minor65]

I agree again with BMC, mine is similar to yours. I left it well alone 10 years ago and no issues yet.

[bmcecosse]

But well done Chris - THAT one HAD to come out!

[katy]

It's interesting to note that they're threaded in, I had suspected that they were just pressed in. Will keep that bit of info in mind - in case.
BTW, what thread are they? I would guess that they're a BSP thread, possibly 3/8"?

[bmcecosse]

5/8" UNF I believe.......

[MikeNash]

Mine was like Chris Ryder's and as I couldn't get it out I screw threaded and blocked it with a bolt with sealant on the threads. Did the same on the block and kept the tap on the heater supply continuously open. Its been OK for a few years now, MikeN.

[bmcecosse]

Ideal! No more ghastly bypass hose to worry about, faster warm up and much improved heater output!! Win Win Win situation.

[moggiethouable]

I would not of course pose any objections to all the aforementioned ideas, I have more sense and they all seem eminently practical.
If you were absolutely bloodyminded enough to remove the offending item though, perhaps an easyout would do it in conjunction with a snug fitting spanner on the easyout and an even more liberal application of easing oil ?[frame][/frame]

[bmcecosse]

Easyouts are the work of the Devil - avoid avoid avoid!

[moggiethouable]

Straight fluted are better than taper I grant you, but Ive had good experiences with both,as for the work of the devil, Eli Polonski holds the patent for the combination unit,the basic fluted taper unit was surely not patented by old nick, the devil is you see, in the detail and needs must when the devil rides
Or as someone once said "when youre up to your backside in crocodiles, you dont stop to feel the temperature of the water".

[bmcecosse]

The problem with easyout is that as it bites into the part to be removed - it expands it outwards - making it grip even tighter in the thread!! Then the easyout snaps - and you are really in the mire....... Welding in a bar as Chris has done is the only way I know to shift these things......but even that is not assured, which is why it's best left alone if it is at all seviceable.

[moggiethouable]

Agreed, which is why I suggested the straight may be better.
If it were me, as I dont have a welder, I would try collapse it with a small chisel and hammer and then remove it and plug the hole, but thats me.
As the coefficient of expansion is different for the plug and head, I imagine the heat from the welder may also help removal, it certainly appeared not to hinder the operation, but thats just a guess.

[gtt1951]

I've made a decision - I'm keeping the stub I have. I did buy a spare from ESM, but this seems to be far too long - about twice the length (see below, still in its bag - scale is Inches)[frame][/frame]
If this were fitted, it may actually touch the one coming up from the pump.
I've obtained a S/H cast iron pump and I have fitted that after a good clean (but not full strip). It is the model that has the grease nipple fitted, instead of the screw plug, for lubrication.[frame][/frame]
Have I done the wrong thing again (see thread in mechanical, 2 cylinders not firing - someone else's)?

George.

[chesney]

I think it's longer as you can slip the bypass on and fit it that way - or something like that, according to the minispares site anyway..

[bmcecosse]

It is far too long -good old ESM - again...... But at least you can fix it with a hacksaw!

[Declan_Burns]

5/8" UNF I believe.......

No, UNS and there are plenty being sold with the wrong thread.

See my earlier post
http://www.mmoc.org.uk/viewtopic.php?f= ... NS#p358330

Regards
Declan

[mogbob]

Declan
I'm familiar with UNF and UNC but not UNS.What's UNS please ( my education obviously has a blank that needs filling in ) ?
Bob