What did you do to your 850/X70 today???

[EMM]

Went down the scrap yard and got

Brake Master Pressure switch (and fitted)
Front lower under tray

All for the sum of £10. Bargain

[Dancake]

Had a loud squeal under braking from the front end. Removed both front wheels and inspected everything. The only thing out of place was the passenger side brake disc retaining screw (also used to help locate the wheel properly), and the brake disc was actually able to move very slightly because the retaining screw wasn't tight. Someone had cross threaded it, so I re-tapped it and fitted a standard M6 screw. A quick road test confirmed that the noise had disappeared.

[volvo again]

Originally Posted by Dancake

Had a loud squeal under braking from the front end. Removed both front wheels and inspected everything. The only thing out of place was the passenger side brake disc retaining screw (also used to help locate the wheel properly), and the brake disc was actually able to move very slightly because the retaining screw wasn't tight. Someone had cross threaded it, so I re-tapped it and fitted a standard M6 screw. A quick road test confirmed that the noise had disappeared.

Surely the 5 wheel bolts would keep the disc on firmly???
Anyway seems you sorted it.

[Dancake]

Originally Posted by volvo again

Surely the 5 wheel bolts would keep the disc on firmly???
Anyway seems you sorted it.

I was expecting someone to ask that. With the wheel bolts on the disc didn't move. I should have stated that the brake disc was only able to move with the wheel off. It did however appear to be the cause of the noise

[volvo again]

MOT today...annoyed, it failed!!!
Failure? Headlight levelling system inoperative...
Last years test I had to replace both headlights as the reflectors were u/s, the new ones came with manual adjusters fitted so I left them as they were, passed no problem
New MOT rules now mean if it should have electric adjusters as standard fitment they must work...good job I kept the old ones, maybe I should have just removed the switch...

[ASt85]

Waiting whilst the MOT is done is worse the going to the dentist................

Changed the plugs today on the T5....don't think any more than pots 1, 2 and 3 had been changed since the car was built (approx 115K on the clock), all three way over tightened ! Pots 4 & 5 were much easier....pointing to someone not moving the turbo tube to get to the coils

The gaps on all were huge, literally no exposed electrodes left on 4 and 5!

I deftly broke the locking clip on pot number 3's coil connector when I removed it but managed to securely cable tie it back into position.

[Cookeh]

Originally Posted by volvo again

Surely the 5 wheel bolts would keep the disc on firmly???
Anyway seems you sorted it.

The disk retaining pin does so much more than just retain the disk. Volvos alu wheels are all hub balanced. The pin ensures the alloy can only be mounted in one orientation and hence ensures both hub and wheel stay balanced. Without the pin you can mount the alloy in multiple different ways all of which would be out of balance and give the symptoms described.

[volvo2]

A rewarding milestone:

https://www.youtube.com/watch?v=n3Lr...ature=youtu.be

[happy diver]

Originally Posted by Cookeh

The disk retaining pin does so much more than just retain the disk. Volvos alu wheels are all hub balanced. The pin ensures the alloy can only be mounted in one orientation and hence ensures both hub and wheel stay balanced. Without the pin you can mount the alloy in multiple different ways all of which would be out of balance and give the symptoms described.

you might want to rethink all that mate

[Cookeh]

Originally Posted by happy diver

you might want to rethink all that mate

If you could Google the issue, and read Volvos own statements on their aluminium wheels being hub-balanced which would, therefore, require the wheel to be mounted in the same place on the hub each time to maintain that balance, you may arrive at a different place in thought yourself. I would question why if the pin is just there to secure the disk that it has any length sticking out to locate the rim and is not a simple screw - like with any other manufacturer. Doesn't make much sense to go to the effort of designing and making a new fastener if it doesn't have a specific purpose when there are plenty of fasteners on the car already that could hold a disk in place. This does not apply to all wheels, only the hub-balanced aluminium wheels. Wheel-stud centred wheels will not have the lugs that force one orientation (as you so kindly pictured).

To quote Volvo: "Most of the competitor wheels are adapted to suit most cars, which means that very often they are centred to the wheel studs. This makes for poor centering and results in imbalance. This in combination with wide tyres is a very uncomfortable combination for the owner.
Volvo aluminium wheels are centred to the hub with very small tolerances. This in combination with small lateral throw and roundness tolerance make for good wheel balance."

If you have something other than hearsay that shows simply that the pin is only there for the purpose of keeping the disk in place, please do post it up. I am always happy to learn the true purpose or correct way of doing things. I believe it's always better to be wrong but learn something than to be ignorant and believe I'm right. Just seems too co-incidental that a hub-balanced wheel which has a specific gap for that specific pin would not actually make use of the pin for anything.