O. L. T.

iTrader: (17)

at only 45 miles every 5 months, it isn't too much concern (but thanks ) This car is my old hooptie. My sandstone one get's most of the love. There's a lot in store for the future though on this one.

Overclocker

Another great write up with pics.

Gonna bookmark this one for sure. Thanks Brian.

gserep1

The AC compressor does not have to be removed on either the 300 or 400 engine to gain access to the water pump. Just remove the bolts and the front bracket above the compressor.

mkorsu

Great write up OLT!!!!!!!!

Just found that my compressor is leaking and I need to remove & possibly replace. (Maybe I'll get lucky and will be able to just get away with replacing the seals).

This DIY is EXACTLY what I needed to assist me with the project.

Thanks again!

fooldall

Just a quick couple Q's on this older thread- How long do you have to replace the compressor before you should start worrying about your drier? Someone told me you need to replace both of those items at the same time because the drier absorbs ambient moisture.. is this true?

Once the compressor is replaced, what is the appropriate pressure for our sc400's? I seem to remember someone saying the "ok" range on those refill kits were too high for the sc400.

Also, any maintenance that can be done on the compressor coil, like, just general cleaning procedures for max efficiency and the like??

Thanks, fellas!

mitsuguy

iTrader: (2)

first off, what year vehicle?

secondly, retrofit or no?

thirdly, those "Refill kits" we refer to as "black death in a can"

drier should always be replaced when doing any work that has had the system open for any amount of time... did the compressor just give up the ghost, or what happened?

fooldall

Sorry, Mitsuguy-

It's a 1992 SC400. Yes, it's been retrofitted to R134a.

Basically, here's what's happening-

In the mornings, it'll blow cool air, not cold- and in the evenings, same thing. During the hottest parts of the day, it will blow cool enough to make the car bearable, but not what I'd consider acceptable performance. I took it to a shop, where the checked for leaks (no leaks) and vacuumed and refilled the system. I have my doubts about the shop though, they didn't seem know the "correct" pressure the system should be at..they refilled it to, i think, 38 psi. Nothing seems to be wrong with the compressor, at least. No blinking AC light (well, it did it once about a year ago but never did it again) and seems to engage normally. While playing with the pressure a bit, I noticed that when I drained some R143a out, it blew cooler..but I'm not sure if this is the correct way of doing things. I saw a reciept when i bought the car where the guy had the compressor, dryer, etc changed when he retrofitted the car about 3 yrs ago. Still blew a just SLIGHTLY cold even when i bought it about two years ago.

Anyway, another question I'd like to ask is if there is any way to clean the compressor coil inside the car...maybe it's also clogged with dust, etc- i did my own cleaning of my house A/C A coil (just under the air handler) and it made a WORLD of difference. I was just wondering if the same thing can be done on our cars...just maybe clean the intake?

Thanks!

mitsuguy

iTrader: (2)

Well, first off, pressure is not an accurate way to judge how much refrigerant is in a system... It must go by weight... our cars call for 2 lbs of refrigerant, being that yours has been converted, 30 oz is the correct charge...

you may just have a problem that our evaporator cores and condensers were never designed to be used with HCF134a... there is an evaporator core inside the car that can be cleaned (assuming thats the thing you are talking about in the home unit)...

fooldall

One more thing- after the A/C diag i ran, it gave a code 41 - Air Mix Server Motor Circuit..

Also, where would I go to clean the evap core?

mitsuguy

iTrader: (2)

evaporator core is in the dash... granted you don't need to cap it off and remove it, here are the instructions:

mitsuguy

iTrader: (2)

and here's code 41 troubleshooting:

fooldall

Wow, Great info! Do you have a service manual or something? If so, where can i get one? I really like the concise descriptions and methods of repair..really cool.

Thanks again for taking the time to describe this to me, i really appreciate it.

So, according to the description listed above, I access the evap core (just for cleaning) through the footwell.. good info..


Also, have you ever replaced a servo motor? Does it require any special tools? I am assuming before I tackle anything else in the A/C system, i should take care of this code 41 thing. At the shop I was at, they said there were no leaks or anything- so I should be ok there.. Any other suggestions? It seems to me that based on what the servomotors function is, and my symptoms- incorrect air mix seems like a likely culprit.

Thoughts?

mitsuguy

iTrader: (2)

I agree about the air mix being the issue - sounds like the air mix door or servo is stuck keeping a little air still coming over the heater core...

I have never replaced one in the SC, however I've never needed anything other than basic hand tools on any other car...

The info comes from Mitchell, our company has a shop subscription

fooldall

Yeah, i suppose that I'll go ahead and adress that issue first- since it seems to me that replacing other expensive parts would be a waste of time if this component is having issues.

Any info in your guide about how to actually get to this part? Where is it, etc.. unfortunately, i have no idea where to begin looking.

Thanks for the info, i really do appreciate it, I love this car- even for it's age and cosmetic flaws it's still the smoothest and coolest car i've ever owned..

SCpwner

Can you just unplug the AC or do you have to completely remove it?