Warning indicators turn on for the system braking components such as ABS brake failure, traction control and loss of engine power while accelerating between 35 to 50 miles per hour. Engine power decrease and the car speed and power is decreased with the loss of engine power warning. The car would just stop at this point. I contacted onstar each time this issue occurred to a diagnostic scan and each report indicated that same warning reported on the console. After 10 minutes the vehicle would re-start and I was able to drive it. This issue has re-occurred within 2 years and the GMC service department was unable to diagnose the problem but during the latest incident the mechanic had ruled the issue as low brake fluid. I've investigated this issue online on various blog forums for the GMC Acadia with the same description of braking system failure and others report the failure as an internal braking malfunction in which the master cylinder leaks into the brake booster. I'm concerned that this problem could potential become fatal is it recurs. The GMC service department refuse to look into my concern and investigate the problem. There are no visible signs of a leak because the leak is internal.

- Pflugerville , TX, USA

While getting repairs for my 35R wave plate (ODI 10550736), the dealership told me that my master cylinder was leaking into the power brake booster and needed to be replaced. Like the 35R wave plate, this seems to be a common issue with the Acadia. I was told that if I did not replace the master cylinder, eventually, the brakes would fail.

- Zionsville, IN, USA

Fluid leaked from master cylinder to power booster no visible leaks repaired at my expense about a week later a bulletin from GM that was to extend my warranty to 10 year 120000 miles. There is a process in place to return my money. No safety recall ! both front struts have gone out. The air conditioner is causing problems because of off and on cooling. All of this is with in 55000 miles, the car has 55055miles as of this dated. There seems to be a process of no safety recalls but to issue extended warranty. We all know what recalls do to sales.

- Olive Branch, MS, USA

Multiple problems with this vehicle. It has been in the shop more than 10 times in the past 4 years that I have owned it, frustrating. List of repairs: Timing belt, head lights, steering, camshaft, oil leak, struts, brakes and this is what I can recall mostly.this vehicle has had multiple services especially for service stability track that never gets repaired, they can't find the problem. Also service air bag keeps coming on but dealership cannot do anything while the light is not on. Very frustrated with this vehicle. I have never experienced so many repairs and services with any other vehicle as I have the Acadia. I owned a galant car before the Acadia for 5 years and only had to do one repair in those 5 years I owned it. I regret purchasing this vehicle! I am a single mother of two and I need a dependable vehicle not one that is malfunctioned!

- Dallas, TX, USA

Driving at slow speed and warning light came on that needed to service brakes. I took it to the local john elway Chevy dealership for service right of way. They came back that the master brake cylinder was leaking and had to be replaced. I am 63, probably have had over 15 brands of cars that I drive to at least 125,000 miles and never replaced a master brake cylinder. I went on edmunds.com online and read multiple complaints from other Acadia owners with even newer models with same problem. I called GM and asked for them to pay for repair, they refused. The mechanic showed me where the master brake cylinder was leaking. He indicated that it is glued together.

- Littleton, CO, USA