Hi guys,

I'm almost working day and night on the GLT for the BKV in UK... It's horrible, I just wanted to repair the struts, finally I also removed the engine so I can check and replace more... I hope it will be done for the meet!!!
Quick question: I made a full restoration of the spare front struts I had (new coating, springs...), they look very fine now... I also replace the whole brake system etc etc... I got new bolts from Volvo for fitting the new brake discs, the last available bolts in Belgium... But of course the bolts for the calipers on the struts are NLA. I really want to change them (rusty and not really looking good)

They are quite specific ("100" reference" on it + a kind of Tensilock head). I got from a supplier something different, he said it was nearly the same and perfect for the brakes. I would like to have your advice. What I got is:

Make: SQUF
Reference: D961 M12X1,25X30 10.9 TPBT S 5

They are a bit shorter (2mm), it's 10.9 (strong enough?) and they don't have any Tensilock.

What do you think? Can I use the new bolts? Here crappy Blackberry pictures

The old ones:
The new ones:

Mac's your man for this one,

I'd be thinking of using a washer aswell as the new bolts aren't flanged head but I'm no expert

Well yes, it's my biggest worry, the absence of flanged head...

will be fine but only with a chemical locking (Loctite 243 in this case) on the bolts, as mr Nimminz says; also use a washer or you'll damage the coating/paint on the calipers.

Thanks for the point of view. In fact the head of these bolts isn't in contact with the caliper, it comes directly on the front strut (rear).

It can be a very warm environment, is Loctite really ok for this?

Ah yes - the caliper carrier bolts (the ones through the strut eyes and into the carrier body - not the calliper to the carrier)

Long and hard have I searched for these- no luck so far - at least not with all the OE features (32mm length, serrated flange head, min.10.9grade).
Firstly the markings '100' - this is equivalent to 10.9' next the serrated flange head - this combines locking and load spread.
If you can source bolts long enough then provided you use a "thick" washer (2mm) and appropriate thread locking (there are loctite products quite suitable) then a "normal" (hex) head bolt will indeed be fine.

As you have found Aymat, the easy one to find is 30mm - already 2mm short BEFORE you add a 2mm washer - now you're 4mm short - no!, I would not use them! Go for next preferred length up - ie. 35mm. ( you may need to run an M fine tap through the carriers to clean out the last bit of thread in the carrier bores - they are not always fully threaded through.)

Mac.

Ps Aymat - I can supply M10x1.25 x25 index caps crews (to secure discs to hubs) in grade 12.9 (see my boltshop at the BKV.

Mac, you surprise me everyday This is exactly what you describe... OE bolts are 32mm long and they have a serrated flange head. I didn't know that 10.9 the same was as 100, very interesting to know.

Well yes, impossible to find a bolt with the same specs, I asked to a lot of industrial suppliers, no chance to find it.

I'll follow your advice, I won't use the 30mm long bolts I got today, I'll buy the 35mm and I'll use a 2mm washer. Do you recommand a specific washer type? All details are welcome so I can directly buy the right one!

(nice that you can supply the bolts for the disc on the hub, I'm interested!)

Aymat - nothing specific on washers except - steel, thick, ie. 2mm or so. ( due to the fairly high torque loadings I would not use a "std. "thin" washer).

Use a quality thread locker - loctite 243 should be fine (it's working range goes up to 180degC) - if you're really worried about brake temperatures (if you are an "enthusiastic driver") you could go for loctite 278 (which also has a higher breakaway torque).

If you need any more disc to hub screws I will have supplies at the BKV.

Mac.

Mac,

I followed your advice, I bought the same bolts but 35mm long, I have washers too and Loctite.

Back to work on the GLT this evening / night, I nearly don't sleep anymore

Good effort Aymat! It will be worth it!