Bridge bolts
NO attempt must be made to remove the two bridge bolts joining the two halves of the caliper together. There is no point in doing so and in addition, the torque loadings to which the bridge bolts are tightened are critical.
When, in an emergency, the bolts have been removed and, in the event of the fluid channel seal being undamaged, the caliper and bridge bolts must be scrupulously cleaned, dried and reassembled. Then, the bridge bolts tightened to the torque loadings given after the next paragraph. When reassembled, the caliper must be checked for fluid, leaks under maximum pedal pressure before refitting it to the car.
It must be understood that this will only provide a temporary remedy and the caliper must be returned to the manufacturers for overhaul at the first opportunity.
Bridge bolts - inner |
60 lb. ft. |
(8.30 kg. m) |
Bridge bolts - outer. |
45 lb. ft. |
(6.22 kg. m) |
DISCS
The disc must be renewed when it has excessive run-out, suffered damage or become excessively scored.
Run-out
Excessive run-out of the disc causes the brake pads to knock the pistons back into the caliper and creates excessive pedal travel when the brakes are applied, thus it is important to keep the run-out to the specified minimum 0-004 in. (0-10 mm)..
When the run-out exceeds this figure, the disc can often be repositioned in relation to the hub to obtain a more satisfactory combination of manufacturing tolerances. |
To check
1 .Apply the handbrake, Jack up the front. of t he car and remove the front wheel.
2. Prise off the hub cap, discard the split pin and tighten the castellated nut to a torque of 15-20 lb. ft. (2.07- 2.76 kg. m) whilst rotating the hub.
3. Mount a dial test indicator on the caliper or stub axle carrier so the stylus bears upon the disc approximately 1.00 in. (25 mm) from the outer edge.
4. Rotate the disc and note the D.T.I. reading, when the run-out exceeds the specified figure it may be some- times reduced by repositioning the disc on the hub.
5. Set the hub endfloat, see under "Hub adlustment" in Section F.
6. Check the run-out as described in operations 3 and 4. Should the run-out exceed the specified figure an investigation as to the condition of the hub bearings must be made.
7. Lock the castellated nut using a new split.pin, fit the hub cap, front wheel and remove the jacks.
To remove and refit
1 . Apply the handbrake, jack up the front of the car and remove the front wheel.
2. Remove the caliper from the stub axle carrier, see under "Caliper-To remove and refit", suspend nearby without straining the flexible hose.
3. Remove the disc and hub assembly from the stub axle, see under "Hubs - To remove and refit" -Section F.
4. Remove the disc from the hub by withdrawing four bolts and washers.
5. Refitting is the reverse of the removal sequence but
particular attention must be given to the following:-
(i) Ensure the fitting faces of the hub and disc are free from dirt and burrs. In the instance of a replace- ment disc ensure that the protective coating is completely washed off.
(ii) The four bolts are tightened to the torque given in the "General Data Section".
(iii) The disc and hub assembly is fitted and the disc run-out checked, see under "Front hub -To remove and refit" -Section F and "Disc run-out -To check". |