[DML] Re: AC Rubber tubing
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[DML] Re: AC Rubber tubing

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,


 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 
> to gum up and eventually ruin the compressor. For now, if your
> compressor and clutch operate fine, I wouldn't bother changing 
> 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 
> The old A/C hoses dont tend to leak 134a if they have been used in 
> past by R12.  They would leak if you put in brand new (old) R12 
> 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 
> replace my cooling fans too. I bought Toby's new low-power high-
> 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 
> function, but are a nice safety feature incase of overcharge, stuck
> compressor, or failed cooling fans.  John Hervey's new hoses dont 
> 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 
> do replace it, replace it with one of these.
> The Evaporator is the most difficult part to replace.  Thankfully, 
> 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, 
> removed mine and cleaned it out.  Junk and debris get in through 
> 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 
> 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 
> 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 
> 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.  
> there is a very small leak, the escaping refigerant will take a 
> of the oil with it. This will stick to the spot its leaking from, 
> cause it to get dirty much quicker than other parts. I had 3 leaks 
> 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 
> 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 
> 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 
> 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 
> > done by the previous owner in March of 2004 (about a year before 
> > bough the car).  The record shows he bought a $34 R134A 
> > kit.  This doesn't sound like he replaced any major parts, does 
> > How extensive is a "kit"? I think I should probably change the 
> > and major components that I am able to, then bring it to the 
> > for final tweaking and refilling.  Is that reasonable, or are 
> > 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 
> > > frame by the gas tank (which really wasn't that hard).  It 
> > > having Andy assist me, in that I could bend down the frame 
> > > (not a permenent bend, just a flex) and guide the end over the 
> > > plate nuts while Andy actually pushed it through.  It can also 
> > > difficult to separate the nuts and the lines.  You need to 
> > $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?). 
> > 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 
> > > lines would not disconnect.  With more time they probably 
> > 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 
> > > conversion).
> > > 
> > > Other misc. notes....
> > > 
> > > Be sure to keep the main high pressure line away from the 
> > > shaft.  Many owners have had sudden AC failure when this hose 
> > warn
> > > through by the shaft.
> > > 
> > > Also, John Hervey has not been as responsive as he has been in 
> > > past.  When I made my original order almost everything came as 
> > > should.  I emailed him many general questions about the parts 
> > 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 
> > > 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 
> > > cleaned.
> > > 
> > > Jim Reeve
> > > MNDMC - Minnesota DeLorean Club
> > > DMC6960
> > > 
> > > 
> > > --- In dmcnews@xxxxxxxxxxxxxxx, "sweetp01569" <paul.sweet@> 
> > > >
> > > > I had my R134A recharged last summer, and the AC felt nice 
> > cold at 
> > > > that time  This year, I really don't feel any cold air 
> > 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 
> > 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 
> > is it 
> > > > worth investing in Special T's spliced tubing (I don't have 
> > or 
> > > > patience to lift the car body to replace with whole 
> > and 
> > > > replacing the long runs under the car?  Can I just replace 
> > easily 
> > > > myself, or do I need an AC shop to evacuate any remaining 
> > for 
> > > > safety/environmental reasons - or is there not enought to 
> > 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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