How often should A/C hoses be replaced? - Page 2 - PeachParts Mercedes-Benz Forum

dkr · #16 06-20-2017, 01:24 AM

I would agree with that... if you're going to do it right. So, what is the final solution? Pre-emptively replacing the compressor as well? What about the evaporator? What about the fan? What about the climate control unit and the vacuum bits under the dash? Your job of doing it right could take dismantling much of the car ... that is if you want something that has all brand new parts. If you don't do that, then your job done right will come with a lot of fine print. And I stand by what I said -- there are issues with technician quality especially on large jobs and there are quality issues with replacement parts. Where do you draw the line?

Dkr.

ah-kay · #17 06-20-2017, 01:40 AM

Quote:

Originally Posted by dkr

I would agree with that... if you're going to do it right. So, what is the final solution? Pre-emptively replacing the compressor as well? What about the evaporator? What about the fan? What about the climate control unit and the vacuum bits under the dash? Your job of doing it right could take dismantling much of the car ... that is if you want something that has all brand new parts. If you don't do that, then your job done right will come with a lot of fine print. And I stand by what I said -- there are issues with technician quality especially on large jobs and there are quality issues with replacement parts. Where do you draw the line?

Dkr.

x2. It takes a lot of $$$, blood and sweat to do everything right in a 30+ years car. Well, get a new car.

HuskyMan · #18 06-20-2017, 09:52 AM

Let's face reality; keeping a 30+ year old car going is not for the faint of heart. That said, a quick visit to the mercedes benz dealer reveals a few items of interest. There appears to be quite a bit of plastic in place of steel on the new MB automobiles. The elegant wood trim that is on the pre 1992 cars also appears to be missing. OTH, there are some great safety and technological upgrades, i.e. side curtain airbags, blue tooth connectivity, etc that are appealing.

So.....it really comes down to TIME. We only have 24 hours in a day, what do you want to spend it on? Personally, I enjoy solving engineering problems, turning a wrench and getting greasy doesn't bother me a bit.

The other day I was reading an aircraft journal. It said there is a very small minority of pilots who are also A&P licensed. The journal went onto say this small group of pilots has a decided advantage. They know both how to fly the plane but also possess a thorough understanding of the mechanical makeup/design of the aircraft. In an emergency, the additional knowledge is PRICELESS.

Same on cars, the more you know and understand about the mechanical components, the better driver you are. One of the top MB mechanics I know said it best; "most people only require two things to drive; their ASS in the driver's seat and GAS in the tank."

Welcome to stupid street.

ILUVMILS · #19 06-20-2017, 12:21 PM

Quote:

Originally Posted by leathermang

Follow your pro's suggestions...
and it would be SILLY to install dye...
for one thing it may contribute to something getting clogged up.. like the TX valve..
AND it WILL NOT SHOW you that the evaporator under the dash is leaking.. and likely not even at high spots in the ac hoses runs...
Suggest you read the AC thread in my signature.

I totally disagree. The dye mixes with the refrigerant oil, it won't clog anything. I've been using UV dye for many years and found it to be the single best method of diagnosing A/C leaks, and it will make it quite simple to detect an evaporator leak. I use a UV light to inspect the evaporator drains and have also used a bore-scope when necessary. This method became the standard routine when we realized the 140 S-Class had a problem with premature evaporator failure and we've been using it ever since.

FWIW, I work at an extremely high-volume dealer. We write between 1,300-1,500 repair orders every month and we'll most likely use UV dye on at least 100 cars before the summer is over. If there was an issue using the method described above I think I would be aware of it.

ah-kay · #20 06-20-2017, 12:29 PM

Quote:

Originally Posted by ILUVMILS

I totally disagree. The dye mixes with the refrigerant oil, it won't clog anything. I've been using UV dye for many years and found it to be the single best method of diagnosing A/C leaks, and it will make it quite simple to detect an evaporator leak. I use a UV light to inspect the evaporator drains and have also used a bore-scope when necessary. This method became the standard routine when we realized the 140 S-Class had a problem with premature evaporator failure and we've been using it ever since.

FWIW, I work at an extremely high-volume dealer. We write between 1,300-1,500 repair orders every month and we'll most likely use UV dye on at least 100 cars before the summer is over. If there was an issue using the method described above I think I would be aware of it.

You disagree with our AC guru here with all his signature links? It is unprecedented. Unfortunately I agree with you too.

83TD · #21 06-20-2017, 01:22 PM

The high pressure hose from the compressor to the condenser on my 83 300TD started to leak this spring so I took it to the local hydraulic shop but they sent me to the transport refrigeration operation along the Interstate and they were happy to rebuild it, using some new and some of the original fittings so it was a drop-in replacement. Not very cheap--$150--but I have cold air again.

I sent the ACC electronics to JamesDean last winter for refurbishing, and bought a new monovalve insert this spring so the climate control is working the best it has in a few years.

Peter

leathermang · #22 06-20-2017, 08:00 PM

Really...on the dye.... you will pay for the work and repair if the dye does cause problems ?
NO... many people are big on opinions when they have NO SKIN IN THE GAME...

To use the dye to check the evaporator you have to get access to it... which is a big job... IF you can even get a mirror and lights to where you can see the fins and tubes.

BUT to check for a leak with a sniffer...
you just turn on the AC and stick the sniffer up to the center vents....

vwnate1 · #23 06-20-2017, 10:55 PM

I'm in LaQuinta, Ca. right now where yesterday in the 120* F heat I was sitting at a red light when an AC hose (or something) blew, what a mess .

I suggest replacing the hoses because they're 30 + years old for goodness sake .

To - Day it's *only* 114* F and we're sweating like politicos on a lie detector .

ILUVMILS · #24 06-21-2017, 12:22 PM

Quote:

Originally Posted by leathermang

Really...on the dye.... you will pay for the work and repair if the dye does cause problems ?
NO... many people are big on opinions when they have NO SKIN IN THE GAME...

To use the dye to check the evaporator you have to get access to it... which is a big job... IF you can even get a mirror and lights to where you can see the fins and tubes.

BUT to check for a leak with a sniffer...
you just turn on the AC and stick the sniffer up to the center vents....

First of all, the use of UV dye is approved by Mercedes Benz for warranty diagnosis and repair. What does that tell you? So much for "NO SKIN IN THE GAME".

Concerning the use of sniffers, in my experience they give way too many false alarms. Not a single one of my 30+ technicians even own one.

Next, inspecting the evaporator is easier than you think. Did you miss the part of my post where I mentioned using a bores-cope??? Any MB that uses an evaporator temperature sensor simplifies it even further. Just remove the sensor and guess what's there? The evaporator!

Lastly, whenever I post an opinion I make sure to state it at the beginning of the post. The overwhelming majority of my posts in the Tech Help section are based on nearly 30 years of experience working on Mercedes Benz vehicles exclusively. I have great respect for many of the DIYer's on this forum but I think sometimes it's important to share my perspective from a professional point of view, and do it in such a way that isn't insulting or condescending. How am I doing so far?

Getting back to the OP, in my opinion the owner should simply fix what's broken and then re-evaluate on an as-needed basis............

engatwork · #25 06-21-2017, 12:51 PM

I've never had issues using dye.

vstech · #26 06-21-2017, 04:28 PM

Dyes are fine for the system in moderation.

I don't use them, but I like to replace any issues...

It better be a big leak in the evaporator to show with a dye.

leathermang · #27 06-21-2017, 10:31 PM

Quote:

Originally Posted by ILUVMILS

First of all, the use of UV dye is approved by Mercedes Benz for warranty diagnosis and repair. What does that tell you? So much for "NO SKIN IN THE GAME".

Concerning the use of sniffers, in my experience they give way too many false alarms. Not a single one of my 30+ technicians even own one.

Next, inspecting the evaporator is easier than you think. Did you miss the part of my post where I mentioned using a bores-cope??? Any MB that uses an evaporator temperature sensor simplifies it even further. Just remove the sensor and guess what's there? The evaporator!

Lastly, whenever I post an opinion I make sure to state it at the beginning of the post. The overwhelming majority of my posts in the Tech Help section are based on nearly 30 years of experience working on Mercedes Benz vehicles exclusively. I have great respect for many of the DIYer's on this forum but I think sometimes it's important to share my perspective from a professional point of view, and do it in such a way that isn't insulting or condescending. How am I doing so far?

Getting back to the OP, in my opinion the owner should simply fix what's broken and then re-evaluate on an as-needed basis............

REALLY ????? You think the Dealership has no skin in the game... if something messes up which you can not or do not want to fix they are standing there ready to charge I don't know how much per hour to get you back on the road cool... so they have nothing to lose......and potentially something to gain if the dye does clog something up...

So you compare HAVING to OPEN up the container the Evaporator is IN... to just sticking a sniffer in the vent opening in the car ? I had a leak in my 81 wagon evaporator and it went off like a Christmas tree... I knew I had a leak in the big line across the engine.. it would have been $150 but if the evaporator had a leak the car was not worth fixing. ( steering needed fix also)

Interesting NONE of your techs OWN a sniffer... or you ?

If that is the case how did you get your opinion about ' too many false positives' ?

False Positives are a RED HERRING for this reason...they know already they have a leak because refrigerant has leaked out.. what they need to know is where all of the leaks are located....
a person will be checking the system for leaks by using pressure and a small amount of some sniffable gas added to it.... if they follow the EPA recommended method...

I got my opinions about the dye by doing a lot of reading on Aircondition.com and ACKits.com

Dye may or may not work... sniffing will work if you follow the directions.

AND if you have any visualization abilities... you can understand that if your leak is at the TOP OF A BEND... or the TOP of the evaporator... the amount of dye which comes out may be impossible to see..... dye, just like oil, can pool in low spots... you can not plan on it being evenly dispersed through the system....so Where you install it relative to where you develop a leak later may make a difference

You are apparently planning on enough dye making it to the evaporator.. and leaking in quantities sufficient to see at the bottom of the fins.. dripping off..
OR running out of the condensation tube under the car..... those expectations have real world problems associated with them...

funola · #28 06-21-2017, 10:58 PM

Quote:

Originally Posted by ILUVMILS

First of all, the use of UV dye is approved by Mercedes Benz for warranty diagnosis and repair. What does that tell you? So much for "NO SKIN IN THE GAME".

Concerning the use of sniffers, in my experience they give way too many false alarms. Not a single one of my 30+ technicians even own one.
................

I bought a sniffer last year just to try out and ran a bunch of tests on it (and returned it). At first I thought it was great device to have. With more sensitive testing, I found it gives false alarms. Sure it works great if the leak is big, it will go off by just bringing the sniffer close to the vicinity of the leak. But then you can hear a big leak and don't need a sniffer lol. A very slow leak requires bringing the sniffer probe tip very close to the leak source and that is when it gives false alarm. When the tip touches a hose, condenser etc. it goes off even though there are no leaks.

leathermang · #29 06-21-2017, 11:14 PM

Quote:

Originally Posted by funola

I bought a sniffer last year just to try out and ran a bunch of tests on it (and returned it). At first I thought it was great device to have. With more sensitive testing, I found it gives false alarms. Sure it works great if the leak is big, it will go off by just bringing the sniffer close to the vicinity of the leak. But then you can hear a big leak and don't need a sniffer lol. A very slow leak requires bringing the sniffer probe tip very close to the leak source and that is when it gives false alarm. When the tip touches a hose, condenser etc. it goes off even though there are no leaks.

IF there are NO LEAKS you should not be using the sniffer...
you should be checking for leaks by pressurizing the system and watching the pressure level ...

What brand and model did you test ?
Not all things are of the same quality...
Did you read the instructions ? Did you need to change the tip ? Was the tip the heated type and working correctly ?
What method were you using to test ? Four oz of R22 in Nitrogen ? which is the recommended method to use the sniffer.. or whatever was in the system?

Don't let the tip touch the hose, condenser , etc...

I notice that you do not complain that the sniffer gave FALSE NEGATIVES.... LOL... you admit that they are sensitive...

Diseasel300 · #30 06-22-2017, 08:35 AM

Get real - unless you have a ton of vehicles to work on a sniffer isn't a worthwhile investment for the average car owner. Dye is cheap, it IS effective, and if you're using it properly it will not tear up your system. I've used dye in older Fords and never caused a failure, and they're very well known for issues with "black death". If the dye tears up your system, you have other problems.