The Mitsubishi Pajero Owners Club®

[morphgarth]

I am trying to recharge my aircon on a 92 2.5 TD Paj. It had R12 but was retrofitted with R134 last year, no other components were changed for compatability. It has since lost it's ice cold feel. The recharge canister I have says to charge via the low pressure side. There is a blue inlet on the front of the compressor and a red on the top. Common sense tells me red spells danger and must be the high pressure but 50/50 odds aren't good enough!!!! Please could anyone advise me on which inlet to utilise.

Many thanks in anticipation

Morphgarth

[Google]

[Polly]

I'd like some advice on this subject, too. Is this something you can do yourself or does it have to go to a garage? If it needs a garage, is it something that most of them do or is it specialised? Either way, how much is it likely to cost, just roughly? Thanks.

Polly

[Sam-F]

The high presure in right at the front the low presure is above the pump if it was changed to R134a the service port should have been changed to the push fit type and they are different sizes so you cant mix them up (high is bigger)

[phil.p]

recharging needs to be done by someone that specialises in auto a/con ,it needs to have the correct gas pressure

[Polly]

[quote="phil.p"]recharging needs to be done by someone that specialises in auto a/con ,it needs to have the correct gas pressure [/quote]


Great, thanks

Polly

[more x 4]

or you can buy a DIY kit and as it says on the tin

[gwyneddcrafts]

Get it done by specialist. Never had a paj done but my old 4x4 was around £100.

[monday]

There is a difference in working pressure between the old R12 and the new R134A, the later being higher. If your compressor was not replaced to handle R134A, you will almost certainly loose your Freon charge again. The problem is with the shaft seal of the compressor. R134A will leak through due to its higher working pressure.

Personal note:
The cost of a Freon charge is a fraction of the cost of having a new compressor installed. Loosing R134A (which is CFC free) into the atmosphere will, supposedly, NOT damage the ozone. A choice of addressing the problem by replacing the compressor (costly though) or living with the fact that you will have to get a Freon charge once and while.

[Polly]

[marcsparks]

[monday]

When scientist declared that R12(freon) was thought to be the cause of the growing hole in the ozone, an affordable solution was sought. Therefore, because of the discontinuation of production, the great theory of supply and demand took over.

A suitable replacement was sought. One of the foremost leaders was a refrigerant named R134. Many other substitutes emerged such as Freeze12 and even gasoline. (Gasoline is a great refrigerant but has some unpleasing volatile side effects.) Most manufactures decided the best replacement was R134. Many changes had to be made in the air conditioning system to accommodate the new refrigerant. New hoses, accumulator (or sometimes known as receiver drier), expansion valves, compressors, service fittings and refrigerant oils were first thought to all be needed. R134 conversions were initially involved and expensive.

As more conversions were done the need to do some of the things decreased because better information was available about the characteristics of R134.

R134 became popular with most manufacturers in 1994. Almost all cars and trucks built prior to 1994 had R12(freon) installed in their air conditioning systems.

To change over a pre 1994 vehicle to R134 several things have to be checked. Conversions are now the most cost efficient way to repair a major problem with an air conditioning system. Conversions should be investigated according to cost and feasibility. Check with your service advisor to see if your vehicle would be better off with R134 or remain with R12.

One of the biggest differences between R12 and R134 is the size of the molecules, which means that a small refrigerant leak in a R12 system is a huge leak in a R134 system. Therefore, thorough leak detection must be done and all leaks repaired before attempting conversion. Expansion valves or orifice tubes must be replaced to handle the difference. Suitable or compatible compressors must be in place and a new accumulator or receiver installed.

Most existing hoses on late model vehicles such as your 92TD are suitable for conversion. New R134 service fittings are installed to make sure that someone does not contaminate the system with the wrong refrigerant. Sometimes it is required that a new or additional condenser-cooling fan be installed.

The size of R134 molecules is a problem. Small leaks on an old R12 system are large leaks on the new system. The compressor has to be driven via pulleys and a fan belt through a rotating shaft in the center of the unit. The shaft seal on R12 compressors are not designed ot hold the smaller molecules of R134.

R134 tends not to be as cooling efficient as R12 on some vehicles and may not seem as cold as you might like. Compressor pressures tend to run a little higher than freon systems and sometimes require the addition of an auxiliary cooling fan especially on smaller vehicles and dual unit vehicles such as vans and large SUV's.

Conversions should be done when a major repair is needed or when it is cost effective to your situation. Conversions are not recommended for minor repairs, on vehicles that do not have a problem to begin with or in some cases, vehicles with dual air conditioning systems

[Polly]

Well, marcsparks had me understanding what was going on but Monday has confused me further Is it not Sunday Oh dear, perhaps I should go back to bed

Anyway, what's the upshot for my 1990 MK1? Sweat to death in the summer or have it re-gassed / converted? And, since it needs to be done by a specialist, where do I go to? Thanks.

Polly

[Sam-F]

[Polly]

[monday]

geeez