On January 25, 1999, about 1630 hours Pacific standard time, a Cessna 172L, N7639G, collided with a block wall during a landing overrun at the Santa Paula, California, airport. The rented airplane was being operated by the Oxnard Flying Club under the provisions of 14 CFR Part 91 and sustained substantial damage. The private pilot undergoing instrument training and the certified flight instructor were not injured. The airplane departed Oxnard, California, about 1600 for a local area dual instructional flight. Visual meteorological conditions prevailed and no flight plan was filed. After departure from Oxnard, basic instrument flight maneuvers were practiced. The private pilot was instructed to fly a series of headings, altitudes, and airspeeds. These vectors terminated as the airplane arrived at the Santa Paula airport. The instructor stated the pilot removed the restrictive visibility glasses on the downwind leg for runway 22. He also said the landing was good but the brakes did not seem to hold. The instructor applied brakes, but felt no right pedal pressure. He attempted to skid the airplane from the end of the runway to avoid collision with a wall, but was unsuccessful. The pilot stated he heard what he thought was rain striking the airplane after the instructor called the Santa Paula CTAF on the radio. He said that when he was told to remove the vision restrictive glasses they were on final approach for runway 22. He said their position was close to the runway and they were high and to the left of centerline. He said that if he were alone, he would have gone around for another attempt, and he verbalized this desire to the instructor. He said the instructor responded verbally that they had plenty of room to land, and the instructor then took physical control of the airplane. The pilot stated they began a descending right turn to the runway and touched down approximately halfway down the runway on centerline. He said water was on the runway, and he could tell from action on the rudder pedals that the instructor was applying brakes. There was no apparent braking and the airplane departed the runway. It continued through a muddy overrun area, back onto a taxiway, and then it contacted a block wall. The airplane was secured and subsequently pushed to a maintenance facility. Witness statements in the Santa Paula Airport Association incident record notes that the airplane landed after the halfway point of the 2,650-foot-long runway, and witnesses thought the power was not all of the way off. The narrative section also notes two skid marks were evident before and after the overrun area. The Santa Paula Police Department report notes the private pilot said he touched down on the runway and began to slow down. However, he could not come to a complete stop and turn safely prior to reaching the end of the runway. The instructor stated they possibly misjudged the amount of distance remaining and braking power. He also said they might have hit water, causing them to slide. The annual inspection record for the aircraft dated August 30, 1998, indicated four brake pads and the right main tire were replaced, 163 hours prior to the accident. After the mishap a Federal Aviation Administration inspector examined the brake system. The inspector applied pressure to the brake pedals. Both pedals were firm and two men could not move the airplane.