Front Driverside Break 2007 XC90 FWD 3.2

JCost · Post by **JCost** » 30 Dec 2025, 09:37

Front driver side caliper locked while driving. The slide pins were in rough shape and believe this to be the main cause of the initial problem, I have replaced both front calipers, pads, rotors, and hoses. After replacing all parts and before bleeding the breaks the wheels spin freely. After bleeding the beaks the driver side front caliper will not retract. If i crack the bleed valve and or hose, break fluid is released and caliper retracts and wheel spins freely again. As soon as i apply beaks same caliper locks up. no issues with passenger side. I have checked all new parts and do not believe the issue is there. I believe is up line from the hoses possibly in the ABS unit. Sometimes, not always while bleeding the breaks the traction control light goes on briefly. Any thought. I have tried a 24hr gravity bleed as well. No codes stored

Capndirk · Post by **Capndirk** » 30 Dec 2025, 12:33

I had that problem with the right rear brake on my 740. It was the flexible hose at the caliper. The inner lining of the hose would separate and deflect in such a way that it would serve as a check valve. Reasonably cheap thing to eliminate.

JCost · Post by **JCost** » 30 Dec 2025, 13:09

Capndirk wrote: ↑30 Dec 2025, 12:33 I had that problem with the right rear brake on my 740. It was the flexible hose at the caliper. The inner lining of the hose would separate and deflect in such a way that it would serve as a check valve. Reasonably cheap thing to eliminate.

Hoses have been replaced and checked

Post by **scot850** » 06 Jan 2026, 13:12

It could be an ABS unit or master cylinder problem and nothing to do with the wheel end at all. If you have replaced all the parts (although not listed I'm assuming the hardware was replaced at the caliper.

I'd suspect the master cylinder is the culprit here though. Possibly a failed internal seal.

Neil.