Head torx bolts

tomsheppard · Unread post by **tomsheppard** » 14 Jan 2003, 14:52

I see from the forum that I'll need a T55 socket for the new head bolts. Is the Torx pattern then proud of the bolt head and not recessed into it like a hex key bolt? Haynes say I should use threadlocking compound. Other sources, grease on the threads. I have always understood that you clean block threads out with a tap and lightly oil the bolts before assembly. Discuss.

Unread post by **alan s** » 14 Jan 2003, 15:40

Tom,
The torx head bolts are recessed like an allen key. We have a Torx55 socket with a 1/2" drive so that we can use a tension wrench when refitting. On a 16V it's a case of tighten up, slacken off then retighten & go through "x" degrees to apply stretch.
I suppose others could have other ideas but I personally think it's a case of theoretic reasoning over practical reality using a thread locking compound on the head bolts; they gotta be jokin' I can't see any way in the world they could ever work loose, which is all Loctite is suppose to prevent. For mine, I'd run a plug tap down, make sure they are free & threads clean, & whack 'em in. I've seen more heads and components wrongly tensioned due to crud in threads than I've ever seen come undone because they were lubed!!
I usually use an assembly lube or anti seize lube which should be readily available over your way as we get it here and we still have some people using horses as a major means of transport<img src=icon_smile_wink.gif border=0 align=middle> <img src=icon_smile_cool.gif border=0 align=middle>
Alan S

Unread post by **RichardW** » 14 Jan 2003, 15:49

Tom,
There are 2 types of 'star' (Torx - but that's a trade name) fitting male (like a hex bolt) and female (like an allen key). The males are given 'E' designation and the females 'T'. XUD heabolts are female, thus 'T' type.
If you are reading Haynes, make sure it is the later version which covers stretch type head bolts - the tightening sequence should be torque 1, torque 2, angle. When you angle tighten, you can actually feel them stretch - the amount of torque becomes constant.
As Alan says, I doubt threadlock. Use an oiled tap or old headbolt, and make sure you can run it all the way down the holes in the block with your fingers only before you refit the head. Don't be tempted to add too much oil, as this can puddle in the bottom of the hole and cause a hydraulic lock when you tighten the head down that gives a false reading. Finally apply a light smear of grease to the headbolts when you refit them - and make sure you refit the washers under the bolt heads or you will trash the head!
Richard

Unread post by **Jon** » 14 Jan 2003, 16:30

As Richard says, the headbolts on the car will be female (T) bolts.
To add a word of advice, both Citroen and aftermarket suppliers now seem to be supplying male (E) bolts for the replacement bolts.
I found this the other day when I was doing that head job on a Berlingo 19D. I had the correct tool to remove the bolts, but found the new ones were completely different, ie male. Was gutted and had to proceed to local Halfords to buy the correct tool.<img src=icon_smile_angry.gif border=0 align=middle> Being Xmas eve at the time there were no other options.
Jon Wood
[email protected]

Niek · Unread post by **Niek** » 14 Jan 2003, 16:48

Hi,
Just did mine on a Bx 14i Deauville 10-'92. The head bolts were of the male type, my car still had regular hex bolts in there so I had to run out in my oil-drenched clothes as well (very annoying). I cleaned the threads and screwed the bolts in. The thing that surprised me is that the first phase is tightening the bolt to 20Nm (which is rediculously low, imagine two Kgs at the end of a one meter rod), the second phase requires you to angle tighten them another 240degrees. Basically this means that the 'real' tightening/stretching is controlled by the angle therefore eliminating (more or less) the effects of friction in the bolt holes. I thought that was quite smart.
Anyway it was easier than I thought it would be, just takes alot of time.
Niek.

tomsheppard · Unread post by **tomsheppard** » 14 Jan 2003, 16:57

Thanks, all. As is usual, the only consistent thing is inconsistency! I'll order up some bolts from Andyspares and get the tool when the parts arrive. Bit of a pain, though 'cos I'd hoped to order all the bits at once and I don't yet know how many notches I need for the head gasket- hey ho...

DLM · Unread post by **DLM** » 14 Jan 2003, 20:56

In case I haven't mentioned it before, I was stupid enough to buy a head-gasketed TGD a while back despite noticing the tell-tale bubbles almost as soon as I'd opened the bonnet. I then took it for a test-drive and was won over by the torque and wads of previous service history with a name on it I knew and trusted. I chickened out of doing the gasket myself, but got it done by that trusted name, who were able to confirm that another "mechanic" had got his hands on the car meantime and replaced the head gasket without renewing the bolts (probably didn't bleed it properly afterwards, either, or torque the bolts in the approved manner).
20,000+ miles after the "proper" repair, the engine is still performing perfectly, though I did have to flush the radiator of sediment before taking it on a 2,000-mile-plus round trip to Southern France/Northern Spain and back. You may yet have a pleasant surprise in store....
What did throw me a bit after the head-gasket replacement was that coolant was still forced out of the rad cap for a short period afterwards, but without signs of any back-pressure. This was just the cooling system reaching a state of equilibrium after the recommended overfilling/bleeding procedure.

tomsheppard · Unread post by **tomsheppard** » 14 Jan 2003, 21:08

Yep, that's just what I did. The car itself though seems to be a good'un so I will at least give it a fair hearing. If your TGD had been fixed properly in the first place, then it wouldn't have come up for sale, i'll bet.

tomsheppard · Unread post by **tomsheppard** » 15 Jan 2003, 15:13

Good old GSF. I quoted the Andyspares part numbers and the kind gentleman on the other end of the phone went and had a look. For the record, they are supplying female headed bolts. The suitable tool is a T55 driver on a 1/2" drive available from your local branch of Churchill Tools for a fiver.