[DML] Re: AC Rubber tubing

["sweetp01569" <paul.sweet@xxxxxxxxxxxx>]

Thanks Jim,

My compressor and clutch are OK, and believe my condensor and 
evaporator are relatively clean.  I ordered a new accumulator, VOV 
orifice tube, low pressure cycling switch and pressure relief 
valve.  When I receive these items, I will make an appt with the AC 
shop and request they do the flush to get out the old oil, leak test 
and refill with the proper amount of R134A (which is 2 to 2.2 lbs, 
right?).  One other question.  Should I change all the o-rings, even 
for fitting or hoses that I am not replacing, or best of left alone 
for now?

Thanks again,

Paul

 on --- In dmcnews@xxxxxxxxxxxxxxx, "Jim Reeve" <dmc6960@...> wrote:
>
> Well, if all the previous owner spent was $34, it certainly wasn't
> done properly.
> 
> First and foremost, the R12 oil is still in there.  A no-no for the
> long term, but usually shows no ill effects for the near term.  The
> oil is critical for the compressor operation. Incompatible oil is 
said
> to gum up and eventually ruin the compressor. For now, if your
> compressor and clutch operate fine, I wouldn't bother changing 
them.
> Have an A/C shop do a flush when you have the remaining 134a
> evacuated. Not sure what it involves, but it is supposed to get the
> old oil out. My compressor clutch was failing, and I also had 
leaks in
> a few different spots on it. (How do I know? Read on...)
> 
> The hoses themselves probably arn't the source of your current 
leak. 
> The old A/C hoses dont tend to leak 134a if they have been used in 
the
> past by R12.  They would leak if you put in brand new (old) R12 
hoses
> and charged with 134a.
> 
> The condensor is probably ok and doesn't need replacing, but it 
may be
> full of bugs, dirt, road-grime, etc. after 25 years reducing its
> effectiveness. I chose to replace mine with my conversion since I
> needed a new radiator anyways, then while I was at that, might as 
well
> replace my cooling fans too. I bought Toby's new low-power high-
flow
> fans, can't wait to turn them on! The higher airflow not only
> increases the radiator's effectiveness, it also increases the A/C's
> effectiveness.
> 
> Next comes the high pressure switches.  They arn't critical for 
normal
> function, but are a nice safety feature incase of overcharge, stuck
> compressor, or failed cooling fans.  John Hervey's new hoses dont 
have
> ports for these, nor on the new condensor (like some D's), yet he
> still sold me a new high pressure switch and relief valve, need to
> talk to him about that.
> 
> The Orifice tube (in the high pressure inlet for the evaporator)
> should be replaced if you do the high pressure short line, but it
> wouldn't be critical if you didn't.  Since 134a has less cooling
> capability, a new type of orifice tube, called a Variable Orifice
> Valve or Smart VAV has been developed to assist performance.  If 
you
> do replace it, replace it with one of these.
> 
> The Evaporator is the most difficult part to replace.  Thankfully, 
it
> is the least necessary to replace.  You need to be carefull
> disconnecting the lines to it to make sure you dont twist its metal
> tubes and cause a leak.  Me being super thourough with my rebuild, 
I
> removed mine and cleaned it out.  Junk and debris get in through 
the
> fresh air intake and plug it up.  Back in 2001 I was able to
> significantly clean it out and increase airflow by reaching my arm 
in
> through the blower motor opening and pulling out gunk. This time I
> wanted it completely clean so I simply (or rather not-so-simply)
> removed it.
> 
> Now comes the Accumulator/Dryer.  This is where the excess 
refigerant
> and oil is stored in the system. It also contains a desiccant to
> remove stray moisture from the system.  This should certainly be
> replaced if you do nothing else. The low pressure cycling switch is
> also attached directly to this.  I have observed a moderate failure
> rate with this part, so I would also recommend replacing it.
> 
> Now, for those who kept reading to find out how I knew about 
certain
> leaks, here it is.  I had no dye in my old system. Didn't need 
it.  I
> watched for rapid dirt and grime buildup on my A/C components.  
When
> there is a very small leak, the escaping refigerant will take a 
little
> of the oil with it. This will stick to the spot its leaking from, 
and
> cause it to get dirty much quicker than other parts. I had 3 leaks 
in
> my previous system. Two on the compressor (O-rings for the high/low
> pressure line connections [repairable with new O-rings], and one on
> the weep seal for the clutch shaft [not repairable]), then also a 
leak
> on the high pressure line connection to the evaporator.
> 
> Other things to note, on ANY connection that is taken apart, the
> O-ring should be replaced with a 134a compatible GREEN O-ring. It 
is
> designed for it. John Hervey's new hoses have the green O-rings on
> them. The only one I had to buy was for the evaporator/accumulator
> connection.
> 
> One more reminder to make sure your long high-pressure line is 
CLEAR
> of the steering shaft!!!  This goes for those installing new hoses,
> and those who have never touched their A/C systems! You dont want
> rubbing which WILL blow the hose. I personally know TWO Delorean
> owners this has happened to.
> 
> Make sure you have 19mm, 22mm, 27mm, and 32mm wrenches.
> 
> Jim Reeve
> MNDMC - Minnesota DeLorean Club
> DMC6960
> 
> --- In dmcnews@xxxxxxxxxxxxxxx, "sweetp01569" <paul.sweet@> wrote:
> >
> > Thanks for the great replies.  I didn't do the conversion.  It 
was 
> > done by the previous owner in March of 2004 (about a year before 
I 
> > bough the car).  The record shows he bought a $34 R134A 
conversion 
> > kit.  This doesn't sound like he replaced any major parts, does 
it?  
> > How extensive is a "kit"? I think I should probably change the 
tubes 
> > and major components that I am able to, then bring it to the 
shop 
> > for final tweaking and refilling.  Is that reasonable, or are 
there 
> > other items to be aware of when replacing components?
> > 
> > Thanks,
> > 
> > Paul
> > 
> > --- In dmcnews@xxxxxxxxxxxxxxx, "Jim Reeve" <dmc6960@> wrote:
> > >
> > > The spliced lines are quite nice for ease of install.  Andy is 
> > right
> > > that the hardest part is getting the low pressure line through 
the
> > > frame by the gas tank (which really wasn't that hard).  It 
helped
> > > having Andy assist me, in that I could bend down the frame 
slightly
> > > (not a permenent bend, just a flex) and guide the end over the 
tank
> > > plate nuts while Andy actually pushed it through.  It can also 
be
> > > difficult to separate the nuts and the lines.  You need to 
spend 
> > $75
> > > on a 32mm, 27mm, and 22mm wrench.  19mm is also necessary but I
> > > already had one of those.  There is not much room to work the 
> > wrenches
> > > but it is possible (hey, they got them on there didn't they?). 
On 
> > the
> > > first car I did a few years ago, I could not separate the high
> > > pressure line from the evaporator.  I got the nuts apart, but 
the
> > > lines would not disconnect.  With more time they probably 
could 
> > have
> > > come apart, but I didn't have any then.  My car which I'm in 
> > progress
> > > with was no problem.  If your doing all this, replace the 
> > accumulator
> > > and orifice tube as well (unless you did that with your 
original
> > > conversion).
> > > 
> > > Other misc. notes....
> > > 
> > > Be sure to keep the main high pressure line away from the 
steering
> > > shaft.  Many owners have had sudden AC failure when this hose 
was 
> > warn
> > > through by the shaft.
> > > 
> > > Also, John Hervey has not been as responsive as he has been in 
the
> > > past.  When I made my original order almost everything came as 
it
> > > should.  I emailed him many general questions about the parts 
and 
> > two
> > > that were missing, no responce.  I called him a few times then
> > > eventually got through to him to get one of the parts that 
didn't
> > > arrive, but I still dont have the other one yet.
> > > 
> > > When I arrive in Chicago, every component in my A/C system 
will be
> > > brand new except for the evaporator, which I removed and 
throughly
> > > cleaned.
> > > 
> > > Jim Reeve
> > > MNDMC - Minnesota DeLorean Club
> > > DMC6960
> > > 
> > > 
> > > --- In dmcnews@xxxxxxxxxxxxxxx, "sweetp01569" <paul.sweet@> 
wrote:
> > > >
> > > > I had my R134A recharged last summer, and the AC felt nice 
and 
> > cold at 
> > > > that time  This year, I really don't feel any cold air 
coming 
> > through 
> > > > and the compressor just turns on and off for about a second 
> > every 5 
> > > > seconds or so.  I suspect my charge is gone.  I read that 
older 
> > R-12 
> > > > rubber tubing (I suspect those that run under my car are 
> > original) 
> > > > will actually let the R134A pass through the molecules of 
> > rubber, 
> > > > resulting in a slow leak over the winter.  Is this true?  If 
so, 
> > is it 
> > > > worth investing in Special T's spliced tubing (I don't have 
time 
> > or 
> > > > patience to lift the car body to replace with whole 
sections) 
> > and 
> > > > replacing the long runs under the car?  Can I just replace 
them 
> > easily 
> > > > myself, or do I need an AC shop to evacuate any remaining 
R134A 
> > for 
> > > > safety/environmental reasons - or is there not enought to 
worry 
> > about 
> > > > if I open and replace the tubing before I bring to an AC 
shop to 
> > > > recharge?  Any advice on this subject is appreciated.
> > > > 
> > > > Thanks,
> > > > 
> > > > Paul
> > > > Vin 10944
> > > >
> > >
> >
>









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