M&R Automotive is a leading auto repair shop serving Menlo Park, Atherton, Daly City, Palo Alto, and Belmont. We do first-class work so you can hit the road confident that your problems have been solved. Driving is an unpleasant experience without a functioning A/C. For A/C repair, bring your ride to us for cool and comfortable driving.


Brake Replacement

Your car’s braking system is the first line of defense in an impending accident. Driving a car with bad brakes puts the driver and other road users at risk of an accident. On the other hand, ensuring your vehicles have well-functioning brakes can save your life and other road users. Therefore, ensure your brakes are in good condition before driving.

A good braking system is important to a safe journey. At M & R Automotive Repair, we offer brake replacement services needed for the safe operation of the vehicle. We have expert technicians trained to fix your vehicle brakes. So you can be assured that your car is in safe hands.

SMOG Check

We are a STAR certified SMOG check station. If you need a smog check to register your vehicle in California, we can help. Give us a call if you have any questions about getting your vehicle smogged, or click the button below to schedule an appointment to bring your vehicle in.

How Air Conditioning Works

The compressor pumps refrigerant through the system, cooling the outside air before blowing it into the cabin. Your car’s refrigerant can absorb heat, carry it to another structure, then offload that heat and become cold. It is also a dangerous chemical. You need specialized equipment to work on an air conditioning system. Refrigerant can be caught and recycled. Because refrigerants deplete the ozone layer, we don’t want them escaping into the atmosphere. Evacuating refrigerant into the air is illegal.

If your refrigerant needs to be topped up, it must be with the same kind the system was designed to use. For many years R12 was the standard. It was effective and cheap but was implicated in the depletion of the ozone layer. Its use in the US was banned in 1994.

Most cars on the road today use R134a refrigerant. Thought to be kinder to the environment, since 1994 all cars use this refrigerant. Since then, R134a has been discovered to have greenhouse gas potential, deplete the ozone layer, and persist for many years in the atmosphere. After 2021 this refrigerant is no longer used in new cars.

R1234yf replaced R134a in 2021. This new refrigerant breaks down faster, contributing less to global warming. It’s also compatible with R134a.


If your refrigerant is low or gone, you’re A/C unit won’t work as it should. The symptom of this is warm air blowing through your A/C ducts. After determining the cause of your low Freon, our technicians will rectify the issue and get you on the road in comfort.


Refrigerant molecules are tiny and can slowly pass out of the system. If there is no leak, a small amount may be added to return your A/C to correct operation. Also, there may be a poorly seated O-ring at a joint in the system. Our technicians can troubleshoot a leak and implement a recharge as quickly as possible at an affordable cost. They will evaluate the system to confirm all leaks are resolved and that no other issues are causing improper operation.


Your vehicle’s AC unit will not work as it should if the evaporator, condenser, and compressor malfunction. The condenser releases heat; the part located in the front of the engine compartment looks like a small radiator. The compressor pumps refrigerant around the A/C system. The evaporator is located in front of the firewall. It uses cold refrigerant to cool ambient air blown into the cabin. Any of these parts can leak or malfunction. We will quickly ensure these three essential parts of your A/C unit work as they should.


The A/C dryer filters the circulating refrigerant. Because it can become filled with contamination, the dryer needs to be replaced on schedule. Ask our technician for advice on this matter.