delivered the Opinion of the Court.
This is an appeal by various parties in a consolidated multiple party negligence case from separate orders granting summary judgment on the issue of liability and judgments entered accordingly. The orders and judgments were entered by the district court of Silver Bow County upon application therefor by the moving parties following extensive pretrial discovery.
On August 26, 1968, a water truck owned by Silver Bow County and operated by its employee, Neil Bolton, had an apparent brake failure and careened down a steep grade on Montana Street in Butte, Montana. It struck numerous vehicles, some of which were occupied, and crashed into the showroom of the Wilson Motor Company destroying the building. Numerous suits were filed against Silver Bow County for personal injuries and property damage. In each instance the defendant Silver Bow County filed a third party complaint naming Roberts Rocky Mountain Equipment Company and Mack Trucks, Inc. as third party defendants based upon *372alleged negligent design of the air brake system and negligent installation of a power steering unit.
Subsequently Neil Bolton became a defendant and third party plaintiff with Silver Bow County. Two of the plaintiffs, Joseph L. Wilson, d/b/a Wilson Motor Company, and his property insurer, Hardware Mutual Insurance Company, filed an amended complaint naming Silver Bow County, Bolton, Roberts Rocky Mountain Equipment Company, and Mack Trucks, Inc., as parties defendant. The instant case represents ten suits which were consolidated for pretrial purposes, including rulings on the motions for summary judgment involved in this appeal.
Three motions for summary judgment were presented to the district court: Motion #1 asked the court to rule that the liability of Silver Bow County was limited to the extent of its liability insurance coverage. This motion was granted and is not involved in this appeal. Motion #2 was filed by plaintiff Georgia Reid, who asked for entry of summary judgment against defendant Silver Bow County on the issue of liability. It was stipulated by counsel for all plaintiffs that the decision of the court on this motion would control the suits of the other plaintiffs. The district court granted summary judgments in favor of all plaintiffs against defendant Silver Bow County on the issue of liability. This order and the partial summary judgment entered accordingly is being appealed in the instant case by defendants Silver Bow County and Bolton. Motion #3 was a motion for summary judgment and dismissal from all consolidated cases by defendants and third party defendants Roberts Rocky Mountain Equipment Company and Mack Trucks, Inc. The district court granted this motion and entered judgment thereon, from which Silver Bow County, Bolton, Joseph L. Wilson, d/b/a Wilson Motor Company are appealing in the instant ease.
Pretrial discovery, principally by deposition, disclosed that the water truck in question was a 1957 Mack truck which had *373originally been purchased by Roberts Rocky Mountain Equipment Company. Roberts in turn sold it to the Anaconda Company, where it was used as a water truck. In 1964, Roberts again acquired the truck from the Anaconda Company, who traded it in on a new unit. Roberts refurbished the truck and in late June or early July 1965, sold it to Silver Bow County. The truck had always been equipped with air brakes, but it did not have power steering. Silver Bow County returned the truck to Roberts in March 1967 to have a power steering unit installed. The power steering unit was air operated and utilized the air tank already on the truck. This air tank also supplied air for the brakes.
On August 26, 1968, the water truck was dispatched to North Montana Street to clean the county streets just north of the Butte city limits. Bolton, the driver and an employee of Silver Bow County, flushed North Montana Street with four or five loads of water he obtained from a nearby fire hydrant. Up to this point, the brakes and the power steering unit were working perfectly. In each instance Bolton used the brakes to stop at the hydrant.
Bolton returned to the fire hydrant to refill the truck. He parked the truck on the west side of Montana Street facing south with the wheels turned to the right. When the truck was filled, Bolton got back into it, disengaged the clutch and started the engine. When the clutch was disengaged, the truck started to move. Bolton turned the truck to the left and attempted to gear it down from the second lowest gear to the lowest gear. He attempted to apply the brakes to shift into the lowest gear but when he did so, the brake pedal went all the way to the floor and he had no braking power whatever. He began racing the motor in an unsuccessful attempt to build up air pressure to operate the brakes, throwing the gears into neutral so as not to accelerate the speed of the truck in the process. There was no warning buzzer to indicate that the air pressure had been lost, but there was an air pressure *374gauge for the braking system on the dash which he checked and everything appeared normal at the time he got in the cab. The truck continued down Montana Street picking up speed, striking several vehicles, and finally crashing into the showroom of the Wilson Motor Company building.
The deposition of Charles Herndon, a licensed professional engineer and an associate professor of engineering at the Montana School of Mineral Science & Technology, was taken. He examined the water truck after the accident at the request of Silver Bow County. His examination revealed that when the wheels of the truck were placed in an extreme left-hand position, the left front tire would rub against one of the air lines of the power steering unit. His examination disclosed that the outer cover of the air line had been worn through and that there was a quarter inch hole in the air hose. This hole would allow air to escape into the atmosphere rather than operating the power steering. Herndon indicated that on this particular truck, the escape of air through the power steering unit, in his opinion, would deprive the truck of any braking power. He expressed his opinion that this one particular air hose was installed incorrectly so that the wheel could strike it.
Herndon further testified safe operation of the truck required that it have an audible warning device to warn of low air pressure in the braking system, and that he could find none on the truck during his examination and inspection. He also indicated that the power steering unit should have some type of device to control the air pressure, once the system started to leak. He stated that for safety purposes such a device should be located where the driver could close the line. In his inspection, he found no automatic or manual valve which would preserve air pressure for operation of the braking system on the truck if the power steering unit began to leak air.
The deposition of Harry Powley, parts manager for Roberts *375Rocky Mountain Equipment Company for six months, and parts man for Roberts for the preceding 10% years, was also taken. He testified that it was standard practice in the industry to equip trucks with audible warning systems and the water truck sold to Silver Bow County was equipped with such a device. He stated that Roberts had installed the power steering unit on the water truck in March 1967, and that it had been ordered from Mack Trucks, Inc. He stated the unit came in a kit and should have included both an automatic and manual shut-off valve, although he had no knowledge that they were actually installed on the truck. Powley indicated that the automatic shut-off valve was designed to shut off the power steering when the pressure in the air system drops below 55 pounds per square inch, and to preserve the remaining air pressure for operation of the air brakes. He also thought the manual shut-off valve was mounted on the outside frame of the truck where it could not be activated by the driver while sitting in the cab.
Alex Zbitnoff, the county surveyor, indicated that he did not believe the water truck was equipped with an audible warning device to indicate loss of air pressure. He also expressed the opinion that if the water truck had been free wheeling or out of gear and had attained sufficient momentum, the brakes of the truck would not have held it.
The shop foreman for Silver Bow County at the time of the accident, Prank Kinsella, testified that after the accident he became familiar with the power steering unit that Roberts installed and testified as to the purpose of the automatic and manual shut-off valves. He testified that he had no knowledge as to whether the valves were on the power steering unit at the time of the accident.
The first issue for review upon this appeal is whether the district court was correct in granting summary judgment to all plaintiffs against defendant Silver Bow County on the issue of liability.
*376Rule 56(e), M.R.Civ.P., provides the standard for determining if summary judgment should be granted, in this language:
“# # * The judgment sought shall be rendered forthwith if the pleadings, depositions, answers to interrogatories, and admissions on file show that there is no genuine issue as to any material fact and that the moving party is entitled to judgment as a matter of law * *
A succinct statement of the controlling principle under this rule is found in 3 Barron and Holtzoff, Federal Practice & Procedure, § 1234, p. 122:
“The question to be decided on a motion for summary judgment is whether there is a genuine issue of fact and not how that issue should be determined. The hearing on the motion is not a trial * *
Rule 56(c), M.R.Civ.P., expressly provides for a partial summary judgment on the issue of liability:
“A summary judgment, interlocutory in character, may be rendered on the issue of liability alone although there is a genuine issue as to the amount of damages.”
Reviewing the pretrial discovery as a whole, we find that there are genuine issues of material fact presented concerning the liability of Silver Bow County. Initially, there is the ultimate factual question as to whether Bolton’s acts or omissions were those of a reasonable man under the circumstances. His testimony upon deposition indicates the braking system on the water truck had been operating properly up to the time of the accident; implies that he looked at the air pressure gauge on the dash which showed sufficient air pressure to operate the braking system when he entered the cab after filling the water truck at the hydrant; that he disengaged the clutch in order to start the motor, pressed the starter button and started the motor, turned the wheels to get in the downhill lane of traffic; that the truck began moving faster than he desired; that he attempted to apply the brakes to shift from the second lowest gear to the lowest gear but *377found he had no braking power; that he accelerated the motor while the gears of the truck were in neutral in an unsuccessful attempt to build up air pressure to operate the braking system without accelerating the speed of the truck; and, that the truck struck several cars and the Wilson Motors building. Whether any acts or omissions on the part of Bolton conformed to the standard of care of a reasonable man under the existing circumstances, is patently a jury question not subject to determination by the judge on motion for summary judgment.
While it is argued that Bolton was negligent per se by reason of violation of section 32-21-108, R.C.M.1947, prohibiting traveling on a down grade with the clutch manually disengaged, a well recognized exception is the case of an involuntary violation in an emergency due to circumstances beyond his control. Bale v. Perryman, 85 Idaho 435, 380 P.2d 501; Discargar v. City of Seattle, 25 Wash.2d 306, 171 P.2d 205; Ornales v. Wigger, 35 Cal.2d 474, 218 P.2d 531. The application of this exception raises factual questions.
In addition, there are numerous factual questions involved in determining whether any acts or omissions with which Silver Bow County is chargeable were the proximate cause of the accident. Aside from all other considerations and irrespective of the existence of negligence per se, the question of proximate cause remains a jury question. Pollard v. Todd, 148 Mont. 171, 418 P.2d 869; Faucette v. Christensen, 145 Mont. 28, 400 P.2d 883. Accordingly, it cannot be adjudicated upon motion for summary judgment where, as here, factual issues concerning negligence and causation are presented.
The second issue for review is whether the district court was correct in granting summary judgment and dismissal of Roberts Rocky Mountain Equipment Company and Mack Trucks, Inc., as defendants and third party defendants in all the consolidated cases.
Roberts and Mack Trucks initially contend the grant of *378summary judgment and dismissal as to them was correct, because the acts and omissions of Neil Bolton constitute independent, intervening acts of negligence absolving them from liability. Suffice it to say that our previous holding that material issues of fact exist concerning any negligence on his part proximately causing the accident renders this contention untenable.
Next, Roberts and Mack Trucks argue that the third party complaints of Silver Bow County do not state a claim against them, because there is no right to contribution among joint tortfeasors in Montana and there is no right of indemnity until after payment. This argument misconstrues the gist of the third party claim of Silver Bow County against Roberts and Mack Trucks. Silver Bow County contends it was not negligent and no act or omission with which it is chargeable proximately caused the accident and that liability rests solely on Roberts and Mack Trucks. Here also, our previous holding that there are material issues of fact as yet unresolved concerning the liability of Silver Bow County and Bolton, renders the application of joint tortfeasor and indemnity principles premature. Accordingly, this contention fails.
Finally, Roberts and Mack Trucks assert that the amended complaint of Wilson Motors and its property damage insurer against them does not state a claim based on § 402A of 2 Restatement of Torts 2d, because neither plaintiff is a user or consumer entitled to relief within the meaning of that section and also because some courts have held that this section does not allow recovery on property damage claims. We find it unnecessary in this ease to determine whether § 402A should be adopted as the law of Montana.
The gist of the claim by Wilson Motors and its property damage insurer against Roberts and Mack Trucks is negligent design and installation of the power steering unit, constituting the proximate cause of the accident. The district court previously denied a motion to dismiss for failure to state a claim. *379Ultimate material factual issues remain unresolved following pretrial discovery: (1) Was the power steering unit in fact improperly designed or installed? (2) If so, was this the proximate cause of the accident? Professor Herndon’s deposition tends to support both improper design and installation. The ultimate questions of proximate cause remain unresolved. Accordingly, we are unable to say as a matter of law that the claim of Wilson Motors and its insurer should be dismissed.
It is argued that there is simply no basis for liability on the part of Mack Trucks inasmuch as their last connection with the water truck was in 1957, substantial changes were made in it by installation of the power steering unit in 1967, and assumption of the contractual duty of repair and maintenance by Silver Bow County all relieve it from liability. If these were the undisputed facts, there would be some merit to Mack Truck’s position. However, the deposition of Harry Powley, the parts manager for Roberts, indicates the contrary. In testimony concerning the power steering unit installed on the water truck in 1967 prior to the accident, Powley had this to say:
“Q. I believe we have mentioned Air-O-Matic? A. That is a brand name of the supply unit. This is the original manufacturing company for the Air-O-Matic.
“Q. You deal with that company generally? A. No. This particular unit was purchased through Mack Truck.” (Emphasis added)
And again:
“Q. Do you have that, or since you do have the units, do you have one available in the shop? A. No. They are a special order item only. I assume you are referring to the steering unit.
“Q. In other words, you had one when you installed it back in 1967? A. I ordered it special for the application.
“Q. In 1967? A. Right, for Mr. Zbitnoff.” (Emphasis added)
The foregoing testimony indicates the power steering unit *380was purchased in 1967 from Mack Trucks and if it was in fact negligently designed, there is a possible basis for strict products liability against Mack Trucks. Although Mack Trucks argues that the testimony of Powley, heretofore quoted, was clearly erroneous and was cleared up later in his deposition where he indicated that the power steering kit was ordered from Air-O-Matic, it is dear that in this later testimony Powley was referring to a power steering kit for the truck following the accident:
“Q. You have testified that these kits must be ordered from Air-O-Matic? A. Yes.
“Q. Did you order one of the systems for the county when they replaced it? A. No.” (Emphasis added)
For the foregoing reasons the order granting summary judgment in favor of Roberts and Mack Trucks and dismissing them from the consolidated cases was error.
Accordingly, both orders for summary judgment herein appealed and the judgments entered in conformity therewith are ordered vacated. The consolidated cause is remanded to the district court for further proceedings not inconsistent herewith.
MR. CHIEF JUSTICE JAMES T. HARRISON, and MR. JUSTICES HARRISON and DALY, concur.