If you purchased a rebuilt caliper for the job, read on...there has been an epidemic of improperly rebuilt calipers recently. It happened to me about 2 years ago but several cases have occurred recently. The parts to a caliper are side sensitive. Parts for the left can't be used on the right, etc. However, the outer half of the caliper looks identical from the outside. If a left outside is combined with a right inside, they can't be bled. To check this, look at the caliper. Volvo puts punch marks on the end of the caliper halves. A correctly assembled caliper will have 2 marks on one end. An incorrectly assembled one will have one punch at each end. Let us know what you find.

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'93 850GLT
'83 242TI Flathood