W123 AC hoses and condenser - PeachParts Mercedes-Benz Forum

Demothen · #1 07-10-2016, 04:25 PM

So, I just reassembled my AC system after flushing, replacing the compressor, drier, txv. I tried to pull a vacuum but think I have a slow leak (yes, i know, nitrogen pressure test, etc - I don't have the gear for that, and havent found anyone that does. Lets skip the arguement please)

I noticed during reassembly that the short line that goes from under the turbo to the condenser had a bulge in the outer casing. I messed with that trying to feel if I had a vacuum leak there and the outer casing fell apart. Obviously I need to replace that line, but also the fitting where it connects to the condensor was pretty rusty internally so I was thinking about just upgrade to a parallel flow condensor and replacing all of the large diameter lines in the system. Some of them had a tiny bit of UV dye leaking through them. I had hoped they would last a few years without leaking a noticable amount but that seems unlikely after seeing the condition of the one under the turbo.

A few questions: Will I get good cooling with a new R4 and the parallel flow condensor? It looks like there is a kit for extreme temperatures with a 16x24 condensor, I would normally say it doesn't get extremely hot here, but this year seems to be disproving that.

Are the stock fluid hoses blue? (Condensor to drier, drier to txv). These seem to be much newer than the rest of the system, and in good shape so I was hoping to reuse them.

Would I be better off returning the compressor I have and buying the Sanden kit? It doesnt actually appear that the r4 compressor manifold is available anywhere. Since I have doubts about the condition of the larger diameter lines, I am wondering if its worthwhile to just go to the sanden. What is the real performance benefit to it?

OR: should I buy an AC hose crimper and rebuild all of my lines and use a parallel flow condenser? Anyone know of an affordable one for barrier hoses?

Sigh

funola · #2 07-10-2016, 10:26 PM

How about pressurize it with air which is 78% Nitrogen and get some Mega Bubbles to find the leak(s)? Some bicycle hand pumps go up to 150 psi.

Oatey 8 oz. Leak Detector-45801 - The Home Depot

I think you are better off sticking with the R4= cheaper, less work and perform about the same as the Sanden per Bill Grissom. The Sanden kit has belt stretch problems from what I read which sounds like the mounts are not sufficiently strong. I believe the last mod made to correct the problem was to add a bracket to the oil pan. I'd be concerned with that long term. Will the oil pan eventually crack from stress?

As for the hose under the turbo, it has a heat shrink cover over it. I think it is for extra protection against heat. As long as it does not leak with the Mega Bubbles, the hose is fine. I have a very slow leak somewhere in my system and bought some Mega Bubbles already. One of these days I'll get to it.

Demothen · #3 07-10-2016, 10:52 PM

That hose is definitely kapuut. The heat shrink is in good shape, but i could literally dig a finger into the hose and feel the cords inside it.

I guess there's no harm in pressurising the system with air and using soapy water to look for leaks, since I will have to drain the system and replace the drier again. I am hoping to avoid flushing and oiling the system again except for adding oil to the new condenser and drier since I haven't run it yet (also that was a HUGE mess)

How would you hook up a bike pump (or more likely my air compressor) to the system? Are the shraeder valves compatable? Or is there an adapter?

I found an outlet online that will sell custom built hoses for a very reasonable rate (35-55$ it seems, crimped). They can also rebuild custom hose assemblies if you ship them the old ones. I think all but the low side suction hose and the high side discharge hose and manifold are just standard style hoses with angled ends.

If I went with the Sanden kit I found, I would save having two new hoses made, but really that doesn't even out if I can get mine rebuilt with new hoses. I am afraid that if one of my large diameter hoses is bad, the others are probably not far from failure.

I do want to upgrade to a parallel flow condenser, it's getting close to 100 degrees here.

BillGrissom · #4 07-11-2016, 05:37 AM

Quote:

Originally Posted by Demothen

OR: should I buy an AC hose crimper and rebuild all of my lines and use a parallel flow condenser? Anyone know of an affordable one for barrier hoses?

Search my posts on this. You don't need an AC crimper (though I have one). It would look professional w/ Oeticker stepless ear clamps. You can use a "nail puller" to crimp the ears, even a cheap Chinese one. Many others would also work - Breeze smooth worm clamps, or older finger-locater worm clamps. They used those on many after-market AC setups (ex. my 65 Newport). I forgot the size of that hose, but standard size (-10, I recall). Buy "reduced barrier" if you want smaller OD. All on ebay. Cut-off the old crimps w/ hacksaw and/or cut-off wheel. An R4 works fine for me, as does a Sanden. Haven't tried parallel-flow, but people say 30% better.

Demothen · #5 07-11-2016, 09:39 AM

Oh wow, those clamps are a fantastic idea - if those are good to hold against the high pressures involved in the system. I could probably replace all of my hoses for about $100-$150 with those clamps and some bulk line, or maybe less after some shopping around.

I haven't had time to look through your posts quite yet, but I'll be sure to do so.

That would drop my cost from ~1200 to buy all new custom hoses and a Sanden kit to ~450 to buy a parallel flow condenser and rebuild all of my existing lines.

I'll have to do some shopping around, probably will go ahead and order the new condenser kit today to get ahead of the lead time. Thanks guys!

Demothen · #6 07-11-2016, 10:59 AM

Bill,
You mentioned that you have a crimper. If you don't mind me asking, what brand/model do you have? I've found a fairly inexpensive crimper that comes with dies for original thickness hose. Would that work with full size barrier hose? I feel like that might be a more reliable method than using the ear clamps. I'd rather spend a little more and be sure it will work than cheap out and worry about it failing, since I can't find a lot of mention of using ear clamps for HVAC work with barrier hose.

funola · #7 07-12-2016, 10:38 AM

[QUOTE=Demothen;3614336]That hose is definitely kapuut. The heat shrink is in good shape, but i could literally dig a finger into the hose and feel the cords inside it.

Quote:

I guess there's no harm in pressurising the system with air and using soapy water to look for leaks, since I will have to drain the system and replace the drier again. I am hoping to avoid flushing and oiling the system again except for adding oil to the new condenser and drier since I haven't run it yet (also that was a HUGE mess)

I did a test of the Mega Bubbles and also soapy water. Mega Bubbles wins hands down. Soapy water runs off too fast so you have to constantly apply more. Mega Bubbles lingers even on vertical surfaces and keep on producing bubbles. The test was 150 psi on my manifold gauge set and unbelievably there were micro bubbles at the ferrules! I am going to go test every connections on my test equipment before testing the car.

Quote:

How would you hook up a bike pump (or more likely my air compressor) to the system? Are the shraeder valves compatable? Or is there an adapter?

Basically you need a Schraeder valve to a ball valve to a Tee to a gauge and the system under test. You can make up something or buy the adapters HVAC Hose Adapters Valves and Parts - Yellow Jacket HVAC Supplies/HVAC Products to use with your manifold gauge set.

ah-kay · #8 07-12-2016, 10:59 AM

Quote:

Originally Posted by funola

How about pressurize it with air which is 78% Nitrogen and get some Mega Bubbles to find the leak(s)? Some bicycle hand pumps go up to 150 psi.

Shhhh...

Member here frown on using compress air. It has moisture, not 'dry' enough.

Demothen · #9 07-12-2016, 11:52 AM

Hmm, thanks guys. I may try that before I replace my condenser & drier. I'm going to have to open the system up again anyway, so moisture isn't the end of the world since they system is going to be open and I'll be putting in a new drier, vacuuming, etc.

Looking at my hoses again under UV light, aside from the one that is clearly bad - the others don't seem to be glowing from dye - they are just reflecting the UV(or probably more realistically, the near UV) back at the same color. So I think the rest of the hoses will be fine for a few more years. The company that's selling me the oversized parallel flow condenser upgrade offered to make me a new hose from the union under the turbo to the condenser, so I'll be replacing both hoses that connect to the condenser. Hopefully will have the new condenser kit in 2-3 weeks, so I'll be doing some other work on the car while I wait - probably new rear shocks and possibly reconditioning the fuel tank.

okto · #10 07-13-2016, 12:12 AM

Where are you seeing the Sanden kit for $1200? Last I checked (a week ago) the mount kit with the compressor was $500something with the two custom hoses it needs.

Demothen · #11 07-13-2016, 08:30 AM

I was pricing sanden kit + parallel flow + all new hoses at roughly 1200$

funola · #12 07-13-2016, 08:34 AM

Can you post links of your parallel flow condenser? Price? Does it require special hoses? Does it require custom mounting or uses existing mounting points?

Demothen · #13 07-13-2016, 10:43 AM

I bought the upsized parallel flow condenser from Klima. It comes with a new hose from the condenser to the drier, as well as a short extension to use on the input side of the condenser. It retains the original line from under the turbo to the condenser, but since mine's in bad shape I ordered a new one of those. It comes with custom mounting hardware that should require no modifications to the car.

The normal kit is 16x20, I opted for the oversized 16x24 condenser, which cost about 300$. I'd rather future proof the system for the minimal additional charge of the larger kit.

Since I spend a lot of time in stop & go traffic, I might upgrade my aux fan later to try to improve cooling at idle.

I've decided to retain the R4 compressor I already bought and installed, as well as most of the original hoses since they appear to be in fairly good condition. This saves me a substantial amount of money, and a ton of work. I had previously flushed the system, installed a new drier, txv, and compressor, and added oil per the FSM, but found that it wouldn't hold vacuum - much less pressure, presumably due to one very degraded hose and corrosion on the condenser's hose connections. Hopefully it will hold vacuum after replacing those parts, and I'm still trying to find a way to pressure test the system with nitrogen without spending an arm and a leg. If not, I'll be using UV dye and checking for leaks periodically while I'm filling the system.

My kit shipped out much earlier than anticipated, so I should have it later this week and will hopefully have it installed this weekend. I'll try to document the process, although it seems fairly straight forward from the instructions I received.

funola · #14 07-13-2016, 01:46 PM

If one original hose is bad, what is the chance the other hoses are good? I don't think you can tell by outside appearing of the rubber whether the hose is good or not. Either find what's leaking with pressure test & soap bubbles then replace what's bad, or premptively replace all the rubber with barrier hoses.

Cheap Nitrogen idea: Rig up a 20 lb propane tank as an air tank with a ball valve on it. Evacuate the air out of it and find someone with Nitrogen willing to fill it to 300 psi. I know Costco has Nitrogen to fill their tires maybe you can find one that is willing? Other sources of Nitrogen would be Home AC techs, and not Auto AC since almost none has Nitrogen in their shops.

Where are yo located? May want to update your signature.

Demothen · #15 07-13-2016, 01:58 PM

That one original hose was sitting pretty close to a lot of heat and an oil leak. The others are not showing any leaks under UV, and my system held static pressure fine before I opened it up. They do have slight surface cracks, but no signs of fluorescence or obvious damage.

I found a small disposable nitrogen tank online for ~$15 + shipping that says it's good for flushing or pressure testing systems. I just tried to contact the company that sells it, but they didn't answer their phone - was hoping to see if it was sufficient for at least a couple fills. I can rent a small tank locally for about $30, with another $30 to fill it - but they require a credit check, which I'm not wild about doing for something this trivial.

I have someone who is willing to loan me a regulator, so that problem's solved - as long as I can hook it up to my manifold or the car directly.