The problems with NA air conditioners

There are many cases when the NA6CE and NA8C air conditioners malfunction.
The A/C doesn’t function (or functions bad), there is a strange noise coming from the compressor.
You had it repaired but it stopped functioning again. Haven’t you had this kind of trouble?

The fact is, that to repair the A/C the most necessary things are the knowledge and the technique. Furthermore, it is important that the customer understands the situation.
For example, some might think that if there is a problem with the compressor, it is enough to repair the compressor. Or if there is not enough gas, it is enough to refill it. This kind of easy maintenance might lead to big problems.

Unfortunately, the deteriorated parts mean the A/C’s whole deterioration and this means that the user has to be prepared for big expenses.

This is the reason why Maruha made a plan of using the NB A/C kit to NA6 and NA8.

All the necessary parts are included in the kit.
R12 has been changed to R134.
We think that it is better to buy a new kit than to pay a big amount of money for the repair.

The installation

In regular cases the installation takes less than a day.
Why can an easy repair lead to troubles?

The usual way of dealing with A/C

1. First, if the efficiency is bad, the gas is being refilled and then the efficiency is checked again.
2. It is difficult to get R12 and for this reason Freon is being used as a substitution.
3. By adding additive agent the noise from the compressor is being suppressed.
4. The compressor is being exchanged with a rebuilt one.

This kind of repair method is usual but there are many problems.

First, let us show you the construction of the air conditioner.

The theory is easy but to the repair the technique and knowledge are important too.

The problems of each part


If there is some strange noise coming from the compressor, it means that its life is coming to an end.
In many cases rebuilt ones are being used.
However, the products’ quality changes depending on the maker.
Another problem is the metal powder.
Very fine metal powder is circulating inside the air conditioner unit.
This metal powder becomes the reason for clogging.

By covering the small holes like that of the expansion valve the gas becomes filled up sufficiently. But even with this the cooling effect might not get better.
Exchanging only the compressor doesn’t solve the problems.

The brand-new compressor comes with a magnet switch and for this reason it is safe. Note that in some cases the magnet switch is being sold separately.

Condenser and receiver

Even the condenser that is full of dirt is a part that has to be exchanged. If the cooling effect of the gas deteriorates, it means that the air conditioner’s efficiency lessens very much.
Furthermore, the receiver’s deterioration is very bad too.

Cooling unit

The condenser is being cooled by air and the cooling fan.
The new kit contains the fan unit and a perfectly functioning motor fan.

The pipes

Metal powder and dirt pass through all these pipes. It is difficult to clean them.
If you have them cleaned one by one, the cost will be very high.
The joints of each part are deteriorated and can be the cause of gas leaking, that’s why a new O-ring is necessary.
If it’s a new kit, the O-ring for R134 is included.

Chamber unit

The unit is in the back of the dash panel.

The evaporator and the expansion valve are set up at the core case.
The chamber unit can also be the reason for the bad smells.
When purchasing a second-hand car you might worry about the bad smell when the air circulates.
However, all these worries can be solved by a new unit.
At the time of the air conditioner’s repair the chamber unit has to be exchanged.

The coolant

R134-a has been the coolant (gas) used since NA8.
This can be still purchased for a stable price.
R12 is difficult to purchase. Furthermore, its price is high.

A/C belt and stays

The new kit contains the necessary belt and all the minor parts like the stays and brackets. All parts are new.

We at Maruha care for the best quality and the best driving experience. Feel free to contact us with any questions.


Note that in the case of some car types there is additional work to be done:

1. The NB A/C pipe’s position is different from that of NA and for this reason it is necessary to make a hole on the bulkhead.

2. If turbochargers / superchargers or other tuning parts have been set up, they have to be removed when the A/C kit is being installed.

3. The air conditioner’s compressor’s bracket is fixed to the engine block with bolts. There are cases when these bolts break and get stuck in the block. It might take a lot of time to remove these bolts.


Maruha Motors Co., Ltd.
Ushizuma 2095-6, Aoi-Ward
421- 2106 Shizuoka city, Shizuoka prefecture
TEL: 0081-54-294-0076
FAX: 0081-54-294-1312