No brake fluid to rear calipers.

cmbfoto · Post by **cmbfoto** » 23 Aug 2025, 14:20

Pulled both rear calipers off our 02 XC70 and there's no fluid coming out from the flex hose. I cracked the rear master cylinder line open and bleed a little fluid. The fluid was dirt brown in color. I pulled the pistons out of the caliper housings. Same thing fluid was dirty brown in color with clots of fluid. Cleaned the cylinder bores and lubed the pistons up with fresh brake fluid and reinstalled the pistons into the housings. The flex lines had the same contamination with dirty fluid. I'm at a standstill never had this problem with my other four Volvo's. Need some help please.
I can't locate a diagram for the ABS plumbing. I was thinking of blowing compressed air from the flex line to remove the contaminates in the lines.
Thanks for your help

Post by **jonesg** » 23 Aug 2025, 15:15

What about this,

Vova585 · Post by **Vova585** » 23 Aug 2025, 15:38

Totally with jonesg. System needs to be flushed through bleeding. Power bleeders are awesome tools for this job. Only word of caution they at times leak around connectors(and brake fluid os not the best thing for your paint). If dont want to do it yourself(price of vaccum or pressure bleeder, time, brake fluid..). I think dealer charges around $220 for this procedure.
Also if your lines are original to the car, might not be a bad idea to replace them at this time as well.

cmbfoto · Post by **cmbfoto** » 23 Aug 2025, 17:38

I have the brake bleeder air tool that connects to the caliper bleeder screw. It's supposed to draw the fluid from the master cylinder through the system into the caliper and out the bleeder into the jug. Thats a no go.

Vova585 · Post by **Vova585** » 23 Aug 2025, 18:18

Than try old fashioned ways of brake bleeding with 2 people. Simple and works with this car.

cmbfoto · Post by **cmbfoto** » 24 Aug 2025, 19:00

That was my first try. That led me to removing the calipers and finding out the problem at hand. Ran to the auto parts store and grabbed the pressure bleeder.

cmbfoto · Post by **cmbfoto** » 24 Aug 2025, 19:03

Vova585 wrote: ↑23 Aug 2025, 18:18 Than try old fashioned ways of brake bleeding with 2 people. Simple and works with this car.

That was my first try. That led me to removing the calipers and finding out the problem at hand. Ran to the auto parts store and grabbed the pressure bleeder.

Post by **jonesg** » 25 Aug 2025, 04:37

I think they use independent brake lines down each side of the car to the rear, you might need to disconnect the line at the abs and run pressure through the line toward the caliper , but I expect the junk is in the abs unit.
Or pressure from the master cyl whilst actuating the abs with vida.