A/C Hose Rebuild or Replace?
 

Hello All - One of my A/C hoses just failed and is dripping freon all over the place. I figured the rest of my A/C hoses are probably right behind it.

The question is, should I replace these hoses or rebuild?
If rebuild, do any members here offer that service?

I also intend to replace the reciever/dryer & expansion valve while I'm at it. If there are any other "complimentary" parts I should replace, please let me know.

Thanks as always!

Personally for AC systems I replace hoses as they fail. Rebuilds are fine in my experience. Many AC shops have hoses they will crimp onto your existing fittings.

No need really to do drier/expansion valve unless you are chasing a problem related to those parts. I usually change out the drier and expansion valve pre-emptively only on compressor replacement.

Oh man.

Hate to say it, but how long is a piece of string,etc? Ultimately, it depends how far you want to take things.

Rollguy Rich made some hoses for me (excellent), I made a few for myself (completely fine).
Buying a $100 crimper and a length of #10 hose is pretty easy and straight forward.
If you plan on hanging onto the car, you might as well replace the old non-barrier hose.
Ideally you don’t have to keep opening up the system.

Re:parts, drier is essential. If you’re running 134a and still on the original expansion valve (larger orifice for r12), you might replace that as well. Here’s where it gets slippery… if you’re making hoses, you may consider throwing in a parallel flow condenser (makes huge difference with 134a), a larger aux fan and a modern sanden compressor, etc etc etc :)

I was a big fan of that cheap crimper till I noticed the big suction line between my evaporator and compressor leaks when I bend it. It seals fine under normal circumstances but when I loosened the mounting bracket to move it recently the hose gave out a good hiss at the crimp. It seals great when bolted down but when bent a bit it hisses.

Checked it out with the halide detector and it appears that my DIY crimp isn’t tight enough on the #12 barrier hose. This is a really chunky hose with a inner sleeve. Could be that I recycled the OE fitting with the shallow barbs. My theory is that the pressure of the Chinese hydraulic crimper is the same for all dies but on the bigger hose it has a bigger area to crush so the force is more distributed over the ferrule. Thus a weaker crimp on the huge hose. Maybe.

Bottom line I’ll probably be tearing the system down (again:() and taking the hose to a custom AC shop to get crimped on a superior tool at some point. Right now it seems to hold gas but it feels marginal. Perhaps I’ll have barrier hose barbs brazed on. I think the cheap tool works fine on the smaller stuff but the #12 barrier hose may be pushing its limits.

I rebuilt all hoses except the small liquid lines in my 1984 & 85. Hardest part is cutting off the crimp collars so you can reuse the fittings. M-B used thick metal. Buy quality AC barrier hose on ebay. I used a MasterCool crimper to crimp new ferrules. You could buy one and resell when done for maybe $10 loss plus shipping costs. Or use Oeticker stepless ear clamps. I used reduced size hose for the suction since #10 ferrules fit perfectly over it. I have boxes of hose and ferrules, though used much on my classic cars too.

Wouldn't be practical to do for you, given shipping costs and the need to mark the clocking of the fittings in the car. If you won't do above, take the hoses in to a shop, though they may balk at cutting the thick collars off, and doubt they could source the funky fittings M-B used.

Did you keep turning the crimper until the marks align? I usually go another half turn to be safe. That crimps it to size, not based upon force. I don't see the "cheap" in the MasterCool crimper, as it appears very well-made. Some ferrules may be a little loose and tend to crinkle too much when crimped down to the mark, to not press as evenly on the hose.

Try another pass on the suction hoses, but this time buy #12 reduced-barrier hose. A #10 ferrule slides on quite tight as I recall (needed a little oil) so will crimp tight and evenly. The thinner hose will bend better and look nicer, like on all current cars which use #10 suction hose. I don't know what M-B designers were thinking in using #12 size. Anyway the ID will be #12 so the system won't know you went smaller on the OD.

The problem with just grinding off the old ferrule and crimping on new hose, is that the factory fittings are "bead lock" style, and the hoses will not stay on the shallow barbs. It is best to weld on new barbs, or make completely new hoses with new fittings. If you are planning to use the R-4, new barbs will need to be welded onto the compressor manifold, and to the special fitting on the TXV. What I have done in the past, is to weld on a male Oring fitting instead of a barb on whatever factory manifold/fitting that is retained. That way the hose assembly has new Oring fittings on both ends, and can be easily removed/replaced without cutting off any old fittings. Of course I always suggest retrofitting to a Sanden, and replacing all the hoses (except liquid line), and changing out the factory condenser to a Parallel Flow.

I know Rich. You already warned me a few years ago. I’m an idiot and I didn’t listen. I just went ahead and did it and ended up here. I’m either going to braze on new barbs or just hand the hose to a local AC shop who specializes in recreating vintage hoses from old ones and have it done properly. I suspect they’ll either use braze on barbs or they’ll use new fittings. The fitting under the TXV is an oddball one.

The hose does seal but I don’t think it’s normal to give out a hiss when I flex the union between the rubber and metal. Luckily I built all the hoses with loops for safety wire for blow off protection.

My crimper is a Chinese master cool knockoff. I watched the master cool videos and their crimper makes nicer looking crimps. The use of reduced barrier hose sounds good. I think standard barrier #12 was overkill for this line.

My crimper has a hand operated hydraulic pump. I may not have gone far enough.

Thank you, I may have to do just this.

Thanks Shern, I'm starting to see this is a slipperly slope...
how long did it take you to rebuild the hoses yourself? I have 0 experience in that area.

Thanks Bill, how did you end up cutting off the crimp collars?

This information complicates things.. it makes sense. What's a guy like me to do? I have yet to find anyone that makes these hoses new.

We're talking mins here. It's a matter of cutting the length of hose you need, slipping the barb/ferrule or the bead lock fitting (whatever you choose), placing the collar in the crimper and crimping away.

The two I made were for the installation of a parallel flow condenser.

All of the fittings can be found on eBay. The trick is figuring out which fitting you need... flare, male insert o-ring, female o-ring... etc. It's actually not that complicated. Order the hose size you need, the fittings and you're in business.

I didn't have any experience either but it's a great way to learn.

Alternatively, There is a guy I found in Burbank -after much searching- who still makes custom hoses and is super knowledgable: Ben at Salerno A/C (1698 West Magnolia Blvd).
And of course you could always take a trip out to Rollguy and he'll sort you out.

It does complicate things. I was on the same fence a few years ago and I decided to skip brazing on real barbs. I didn’t trust my TIG skills to make a gas tight seal. And I am lazy. So I ground off the ferrules on the OE fittings and just crimped on new rubber despite being warned. This worked well on my hoses #6-10. I regret not doing so on the #12 suction line.

Another thing I learned in this process was not to do things piecemeal. For example I replaced my compressor, TXV and drier. Then later I discovered my discharge hose leaked. I rebuilt three hoses. Then I discovered my suction line was damaged. I rebuilt it. Then I realized my system didn’t cool that well on 134a. So I added a parallel flow condenser. Lots of recharging and evacuating. Drier swaps. Then my evaporator sprung a leak earlier this summer.

And I inquired here prior to all that. I was warned that I should consider a parallel flow condenser and a Sanden. Did I listen? No of course not. I just went ahead thinking it would work out differently for me and I’d magically get cold AC with the old serpentine condenser + R4 and R134a. :). I discovered I was wrong on my own. I learned a lot but at great time expense.

There is something to be said about making a careful plan about what you want and how to do it before proceeding. Depending on your desired setup you may want to upgrade the condenser and compressor. This will require custom hoses but luckily Rollguy has all that figured out for you.

At the end of the day I needed all new hoses. A new compressor. New TXV ( I converted to 134a). A parallel flow condenser. It was a daunting task to do in one swipe so I stupidly did it one piece at a time. This isn’t even mentioning rebuilding two ACC boxes and five vacuum pods. It’s a big job and it can be done more efficiently if you take a step back and think more holistically. In retrospect it reminds me of chess. You need to look further ahead than the immediate move.

My AC is working pretty well now but I took an inefficient path to get it working. If I had listened more here before cutting I would have arrived at cold AC with a lot less charging and drier swaps. And as I said above I’m probably looking at another tear down to rebuild my suction line after summer ends.

Just my 2c. I’ve learned a lot over the past few years. Some of it the hard way.

+1

Make a plan, do it all at once. Or over the winter…

I took a slightly less circuitous route, though I was standing on the shoulders of Sisyphean giants :).

Thanks Shern for your help and the contact in Burbank. Your report makes me more confident that I could make these hoses myself if I decide to overhaul the entire system.
Did you see a huge difference with Parallel Flow? We are in the same climate, as you know, and my current stock system does ok with San Diego heat.

It’s amazing how some hot weather can motivate an individual to get that AC working. The hard part is thinking it through when you have that single minded desire for that cold air.

To get back to the OP. What to do? I think if you just have a leaking hose, pull it off. Take it to an AC shop who can just crimp on some new rubber hopefully with real barbs. The MB OE barbs are like pseudo barbs. They are shallow grooves. If you are going to reuse the steel tubes see if you can get a barb brazed on.

Then put the offending hose back on the car. Evacuate and charge using the free loan a tool manifold and pump from Autozone. Drive and enjoy the last days of summer and fall. Start thinking about how your dream AC is going to be built while driving in comfort.

PF condenser is a must if you use R134a.

Thank you, that makes sense. I guess I was perfectly ok with my cooling performance before this leak. San Diego is relatively mild, and my OEM compressor and condensor keep up decently. This is why I'm hesitant to buy the farm, so to speak.
Also, do you happen to have an EPC page handy for part numbers? My copy is missing this section.

I don’t have PNs. Almost everything was recycled or replaced with 4 seasons stuff.

Are you running R12 or R134a?

I bet you have half a dozen shops who can build custom AC hoses in your area. This is the one I was going to go to near me. I just found them on Google.

https://www.cal-aire.com/

My experience comes with a very important caveat.
I am running an HC refrigerant: Duracool

So no. I didn’t experience a huge difference.
That said, going from R134a to duracool was dramatic.
Throwing in the PF condenser was like an Olympic swimmer shaving their arms.

Thank you. A previous owner converted my car to R134A, I do not know the extent of the conversion, most as everything looks stock to my untrained eye - just some shiny bits on the charge ports.

Thanks for that link, I didn't realize you were in Southern California also. I'm sure I can find someone who will do this for me.

Ah, that is an important caveat. I don't know what Duracool is, so I'll have to do some research on that. Thanks again, as always.

Another update, in case anyone is interested. I found this interesting website:
https://coldhose.com/products/build-a-custom-ac-hose

They make custom hoses, or you can send in an old hose for repair, or, you can simply buy your fittings from them. Seems like a resource I may use.

Anyone used these folks?

If you’re okay with your cooling performance you can hold off on the parallel flow condenser. My car really benefitted from the PF condenser. I converted to R134a. It went from cool to cold. I wouldn’t go back for anything. It will be a huge improvement for your R134a setup.

If you do switch you’ll need custom hoses. Then there’s the issue of the compressor which will need more custom hoses. The issue with using a service like cold hose is your hoses are made of bent steel sections and rubber sections. They probably cannot recreate the bent metal tubes with off the shelf components. That’s why you need to braze on barbs or male insert o-ring fittings on the metal sections then connect them with rubber.

It’s going to take a plan where you determine each element your system is going to have. That’s why I say don’t come up with something in the heat :) of the moment. Fix it now with a hose, recharge, then plan your dream system in the winter when you have a cool head.

Ahh got it. You just connected some dots for me with that post. Now I understand the braze-on component.
I like your plan, just going to fix the hose and plan out a bigger refresh.

Re question about cutting off the factory collars, it isn't easy. Cut lengthwise at slight angle and radially w hacksaw at the fwd end of collar, as you peel with locking pliers and prybar once you have enough sticking out to grab w a bench vise. The integral coll-o-crimp makes it much harder.

Should I put my mastercool line crimp set in the tool rental list?