AC restore ... replace hoses, or not?

[jeffbottman]

Here is about the millionth AC thread. I want to bring my '86 targa AC to a state of very good reliability. Should I replace the hoses as a matter of course, or trust that the 30 year old hoses are adequate? I know some forum members, such as wwest, believe the original hoses should be good if augmented with a pressure relief valve. I plan to run modern R134 refrigerant. I recharged my system last summer but it only lasted for a month or so.

I'm happy to spend the $$ and effort to replace hoses, but would like your opinions on whether it is a good investment.

--Jeff

[Canada Kev]

I think you may have answered your own question...

Originally Posted by jeffbottman

I plan to run modern R134 refrigerant. I recharged my system last summer but it only lasted for a month or so.

[Arne2]

I replaced mine, going on year 3 with R134a with no loss of charge. I'd recommend it.

[gregwils]

"I'm happy to spend the $$ and effort to replace hoses, but would like your opinions on whether it is a good investment."

Frankly, I would consider it a necessary investment. Did mine two years ago.

[david.avrahami@]

IF $$ are not an issue...you should get a full kit from Griffith that includes hoses, condensers, evaporator etc, and have it installed.

[DaveMcKenz]

You seem to be assuming your leak is from your hoses. This may or may not be true. It certainly would be good to replace your hoses, but you may have a compressor leak or othe leak source. I would probably try to diagnose first then treat the problem.
Good luck,
Dave

[tirwin]

Jeff,

If you are going to run R-134a and you have stock hoses, you should replace with barrier hose. If you choose to buy the replacement hose from Griffiths it should come with a pressure switch installed, which the factory setup did not have.

You will read all kinds of lunacy here, but it's just that simple.

Before you do that though, I would check out the rest of your system. A month is pretty quick to lose refrigerant. You could very well have a leak somewhere else that needs to be addressed too. Maybe you could take it someplace that has a leak detection capability.

At a minimum you need to replace the receiver/drier at the same time you do the R-134a conversion.

While you are in there you need to check out the squirrel cage blower fan in the nose for the front condenser. That is a potential fire hazard. In the late 80's -- not sure what year the change started -- Porsche added an inline fuse. If your car doesn't have one, then add one yourself. It is cheap insurance. Lots of car fires have started because of that little fan.

It is also a good idea to test the fan. Be very careful with the clips that hold the plastic housing together when you go to remove it. The plastic tends to get very brittle with age. If the motor needs to be replaced (a good proactive measure), you have two choices. There is a teeny Allen head set screw that holds the squirrel cage fan onto the shaft. That little sucker is hard to get off. I broke off the tip of an Allen head in there. Hit it with Kroil or PB blaster before attempting to get it off. If you bugger it up like I did, Griffiths (Keuhl) is the only place I know of that sells both the fan and the motor together. And the way the new fan attaches is MUCH better. The original squirrel cage fan is NLA, so just be aware of that. If you can get the old fan separated you can just buy a replacement motor from Pelican. If you can't, call Griffiths and buy the complete unit.

Also, pull your evaporator and clean it thoroughly. I think in discseven's thread there is a good discussion on cleaning/flushing the evaporator.

Giving Charlie Griffith a call won't cost you anything either...

[uwanna]

Took off all the old hoses on my '80SC when I replaced all the main components with O-ring type components. Gathered up the whole bundle and trucked on down to the local industrial hose and fittings company. Most resonable size cities have one
that service hydraulic as well as AC type hoses.
The company I used completely duplicated my whole set of hoses with new barrier hose
and brand new fittings. They offered the older large diameter hose as well as the newer reduced diameter. The only fitting they didn't have was the U shaped one from the compressor to the deck lid condenser, but they can uncrimp and use your old one.
They also "clocked" the fittings 100% correctly.
Here's the best part, turn key cost, right at $125. Yea, you read that right $125.
By the way, it was one day service!

[uwanna]

Got a PM from a Pelican asking about how to find a "hose company"
The company I used is (Royal Brass &Hose)
Here's their website. They are located primarily in the southeast. Check their locations on the site. Good folks, and top drawer service!
Royal Brass and Hose

If you aren't lucky enough to be close to any of their locations, search for the same type of company near you. Hoses and fittings are their business, and most will be more than willing to have your business.

[wwest]

Originally Posted by jeffbottman

Here is about the millionth AC thread. I want to bring my '86 targa AC to a state of very good reliability. Should I replace the hoses as a matter of course, or trust that the 30 year old hoses are adequate? I know some forum members, such as wwest, believe the original hoses should be good if augmented with a pressure relief valve. I plan to run modern R134 refrigerant. I recharged my system last summer but it only lasted for a month or so.

I'm happy to spend the $$ and effort to replace hoses, but would like your opinions on whether it is a good investment.

--Jeff

First, the use of a pressure relief valve, HPRV, is no longer legal.

But you probably meant to say pressure switch to limit compressor operational pressure, a binary or trinary pressure switch. The latter in most common use today.

How many miles on your car, car overall condition, hose condition...?

Both the EPA and DuPont have made public record of the fact that non-barrier A/C hoses that have been previously "conditioned" via the use of R-12 and/or R-12 lubricant will not leak R-134a refrigerant at an appriciable level.

Please note that there are other conditions to consider other than leakage via hose permeation.

Who recharged your system with R-12 without recommending that you add a pressure switch first. I use Gene's Automotive in Bellevue, but be aware, he will not touch a US manufactured vehicle, not that it matters here.

Genes European Auto Repair

Your car has a unique feature in comparison to pre-84's. The cabin heat blower control module does double duty. The extra "duty" involves helping to keep the engine from over-heating when the cooling airflow from the engine fan does not suffice.

As you might guess, this is mostly on a hot day while the engine is idling or you're moving along slowly in stop and go rush hour traffic, say I-405 northbound of Bellevue at 4 PM on a Friday.

The module has 2 inputs that facilitate this extra functionality, an input from the speedometer sensor, and one from an engine oil temperature sensor. If the engine temperature begins to rise beyond the "norm" during consistently low speed operation the cabin blower is powered, helping to cool the exhaust manifold and thereby reducing the radiant and convection heating of the engine itself.

In your case, with A/C, it obviously also helps the condensation of refrigerant in the rear lid condenser while also ducting a substantive portion of the heat from condensation around the engine.

My '88 Carrera has a trinary pressure switch installed with the third element wired, spliced, into the engine oil temperature sensor connection to the cabin blower control module.

There are also a couple of modifications I have done to get more airflow through the cabin heat blower.





The engine fan outflow to the cabin heat blower is now blocked off, closed, and the cabin heat blower intake is open to atmosphere.

More to come....

[wwest]

Originally Posted by uwanna

Took off all the old hoses on my '80SC when I replaced all the main components with O-ring type components. Gathered up the whole bundle and trucked on down to the local industrial hose and fittings company. Most resonable size cities have one
that service hydraulic as well as AC type hoses.
The company I used completely duplicated my whole set of hoses with new barrier hose
and brand new fittings. They offered the older large diameter hose as well as the newer reduced diameter. The only fitting they didn't have was the U shaped one from the compressor to the deck lid condenser, but they can uncrimp and use your old one.
They also "clocked" the fittings 100% correctly.
Here's the best part, turn key cost, right at $125. Yea, you read that right $125.
By the way, it was one day service!

And how many DAYS involved in Remove & Replace...??

Laying on your back....?

[uwanna]

Originally Posted by wwest

And how many DAYS involved in Remove & Replace...??

Laying on your back....?

One day to remove and have new hoses made, second day to replace. Had car up on four tall 6 ton jackstands, so remove and replace a piece of cake! A hell of a lot easier than doing a valve adjust laying on your back and going thru all the contortions neccesary!
I'm not allergic to a little work Williard!

[tirwin]

Originally Posted by wwest

And how many DAYS involved in Remove & Replace...??

Laying on your back....?

So your argument against R&R'ing the hoses is work? You crack me up.

Best to never drive the car then or else you might need to replace the clutch one day!

[wwest]

Originally Posted by tirwin

So your argument against R&R'ing the hoses is work? You crack me up.

Best to never drive the car then or else you might need to replace the clutch one day!

Just wait until you're approaching 75...

Just DIY replaced the tailpipe on our '93 Ford Ranger, 140,000 miles.

No reason for laying on your back DIY if it can be reasonably avoided...

[wwest]

Nostalgic AC - Binary Switch w/ R-134a Discharge Port 7/16" - AC Pressure Switch - Oil & Switches

[uwanna]

Originally Posted by wwest

Just wait until you're approaching 75...

Just DIY replaced the tailpipe on our '93 Ford Ranger, 140,000 miles.

No reason for laying on your back DIY if it can be reasonably avoided...

Hey pal, not so fast! I'm 72, but obviously I'm in a lot better shape than you are.
Just pulled my engine/tranny for refurb and completly replaced the entire suspension front and back last year. Like I said, some of us are not afraid of a little work! Keeps you young! Just ask Tirwin if I can "cut the mustard"!

[tirwin]

Originally Posted by wwest

Just wait until you're approaching 75...

Just DIY replaced the tailpipe on our '93 Ford Ranger, 140,000 miles.

No reason for laying on your back DIY if it can be reasonably avoided...

I'm not going to mention names but there happens to be someone that posted up above pretty close to that age that crawls around under Porsches every bit as good as me, if not better. **cough** uwanna **cough**

You can wish the problem away. Doesn't work too well. Replace the hoses and be done with it. If you want something to be done right, you have to do the work or pay someone to do it for you. I didn't particularly want to have my car off the road for 9 months but I'm glad I did the work. A job well done is very rewarding. When you do something half-ass, that's usually what you get.

[wwest]

Discard the Nostalgic binary switch in favor of the Red Dot trinary pressure switch.

325 PSI compressor pumping limit, safe for our "legacy" non-barrier hoses.


Red Dot Trinary Pressure Switch - Generation II 71R7500 For Sale - DVAutoParts.com

[wwest]

Originally Posted by tirwin

I'm not going to mention names but there happens to be someone that posted up above pretty close to that age that crawls around under Porsches every bit as good as me, if not better. **cough** uwanna **cough**

You can wish the problem away. Doesn't work too well. Replace the hoses and be done with it. If you want something to be done right, you have to do the work or pay someone to do it for you. I didn't particularly want to have my car off the road for 9 months but I'm glad I did the work. A job well done is very rewarding. When you do something half-ass, that's usually what you get.

My suggestions are only "half-assed" if you disbelieve the EPA and DuPont.

Then there is the "misery loves company" group.

Having spent lots of time and/or money doing something only to subsequently to find that it was all NEEDLESS.

[wwest]

Originally Posted by uwanna

Hey pal, not so fast! I'm 72, but obviously I'm in a lot better shape than you are.
Just pulled my engine/tranny for refurb and completly replaced the entire suspension front and back last year. Like I said, some of us are not afraid of a little work! Keeps you young! Just ask Tirwin if I can "cut the mustard"!

Took me YEARS to get the '78 Targa into "shape", damn rubber clutches, now 100,000 miles+ and the only DIY required is regular maintenance routines.

One clutch DIY for the '88 Carrera, otherwise lots of DIY A/C experimentation, alos 100,000 miles+.

2001 C4...., Maybe a battery or 2 in the ~25,000 miles.

Intelligently avoiding un-necessary work does not equate to being afraid of work.

Of course a couple of Advils always helps.