W124 - aftermarket fuel hoses an alarming discovery

$388 for the set locally - it served its purpose of getting the car registered for road use. This would now fail, not only that its a genuine fire hazard. After only 2 years!

[@SuperBackhere]

Cohline is a pretty good brand for fuel lines. I recommend it if you can have access.

[@shaazy]

Do you know the exact size of the fuel hoses? daimeter that is?

[@USSEntrprise]

Cohline, Gates, or any of the prominent belt/tire manufacturers should be good. Here in norway, I only buy Double layered, reinforced fuel hoses from known brand names. I used to run aluminium braid shielded singel layer hoses (as they looked good and I was saving about 5$ per meter), when one day I though the air vents in the car smelled like fuel right after i started the car. Popped the hood with the engine running only to see fuel spraying about 30-40 cm up in the air from the braided hose... Never ever used one layer hose after that to say the least... buy quality hoses, theyre worth it in the long run. New double layer should also be ethanol proof, but make sure!

[@MiguelGarcia-iw6mc]

Cohline is one of the original OE manufacturer of fuel hoses for MB, BMW, Audi... But just be aware of counterfeits and search for high temp versios like cohline 2240 or similar. Not the 2192 low temp like I did for my W124 200D in the past.

[@MMWA-DAVE]

Fyi, Australia version cars have the return line fuel cooler - Theres a heat exchanger on the suction line to the compressor that refrigerates fuel returning to the fuel tank when the aircon is running. The theory behind this is reduced emissions of fuel vapours in the summer time. These little extra hoses as far as I remember are NLA genuine. But there is nothing stopping you from bypassing the cooler and running non cooler version hoses.

[@theundergroundlairofthesqu9261]

I'm in the USA and recently changed those hoses -- but yes, they are NLA from the dealer or anybody else. Amazon Hose in Tampa, FL, built me new stainless-mesh-covered hoses with my old fittings. (Amazon Hose is not related to Jeff Bezos' Amazon.) Note that the fuel pump system on our cars just goes at one volume, and most of the fuel sent forward doesn't get used and goes back to the tank -- a great way to transfer engine compartment heat to the gas tank and gasoline as you drive. And our gas tanks aren't getting any breeze on them, either. Also, cooler fuel makes for more power. I think it's a neat idea! (But I must admit when I first peered into the darkness I thought it was an old timey K/CIS on-the-block warmup regulator.)

[@CarswithNash]

I’m noticing problems with modern rubber components breaking down more and more and I have to wonder if some environmental regulation or something is affecting the way they are making rubber these days… My car still has all it’s original hoses in that area and they are all in great condition still.

[@jonalowe]

I had a Cohline aftermarket hose do that after only 3 years on my W140. It started leaking, and luckily I noticed it. Exactly the same failure mode. I replaced it with an OE Mercedes hose. Hopefully, it's better. Avoid Cohline hoses.

[@sukmyfuk]

I used gates barricade e85 fuel line on my w124 project even though I won’t be running e85

[@theundergroundlairofthesqu9261]

I replaced one long (medium dia.) hose back there about 5-6 years ago, and recently acquired all of the other hoses via my local dealer. I even got the fuel return line elbow-shaped for the other end of the tank from the dealer for a very fair price. (For the vapor return hoses, I needed to go buy two different sizes of Gates hose for vapor (PCV/EEC) which required a more head scratching by more local auto parts clerks than I can go into here. The dealer did have a new plastic check valve for the vapors, too. I mentioned Amazon Hose (not Bezos Amazon) in my comment last night. That was only for the two hoses to and from the fuel cooler in my engine bay. Everything else I've been able to buy. (M103, CIS-E, USA)

[@LilyoftheValeyrising]

I replaced most of my fuel hoses on my ‘75 450SEL with cheap fuel hoses (Autohausaz china). They leaked within a year. This is in Maryland USA so not extreme heat. How I discovered it: hadn’t driven the car in a few months (I drive the 450SL in summer) and my husband started the engine. My gut told me pop the hood and give a visual. The supply from the tank (left side engine) was SQUIRTING on the exhaust manifold. I was furious! I screamed for him to shut down the engine. The direction could have sprayed my face with gas if I was unaware. No fires thank god. I always wear safety glasses I’m thinking of full face shield wtf… I went and got new Mercedes brand hose that day from the dealer $45 for a meter. Is the dealer hose the aftermarket hose? Or the Chinese ones? I would suggest asking Pierre Hedary in Florida if he knows the best hoses.

[@vectortangent4803]

Bloody hell Batman, I’m going to check mine ASAP!

[@tony66au]

With the addition of higher amounts of hydrocarbon solvents into Auto fuels compared to the 80's and 90's your only solidly dependable high and low pressure fuel line today is Teflon and in the aftermarket Teflon fuel line both pressure and gravity is the quality alternative usually using A/N type fittings however any decent hose doctor/Hydraulic specialist will also have teflon hose stock for crimped fittings. Teflon provides total encapsulation, no weep, no vapour and initially introduced for methanol application in top fuel dragsters has since trickled down (Dad joke) to normal automotive use. So if you spec Teflon braided you should enjoy great quality for a long time.

[@wikketube]

I renewed all fuel hoses in my W126 with genuine MB ones this summer. Only after two months the fuel pump pressure hose started weeping some kind of fuel smelling vaseline, it was like the rubber was melting. I got a new one on warranty, and this one is keeping the fuel out still. But time will show. The old lines were 31 years old and still looked quite good. If I remember correctly, the pressure hose was manufactured by Cohline. But maybe it is the same thing like all other genuine parts - they are not so good quality as they used to be back in the days...

[@MMWA-DAVE]

this is very sad to see. I have intentions of buying genuine replacements but not so sure now.

[@MMWA-DAVE]

@Justinian Yi Very disappointing to hear. MB isn’t the same company it once was.

[@MMWA-DAVE]

@Justinian Yi btw, bosch has offloaded a lot of its classic parts to China. Rumours have it this started around the same time part numbers transitioned to F0- part numbers, though i can’t confirm.

[@jamz7058]

I'm following this trend i myself have issues with the fuel injector hoses for my 1973 MB 450SL. It was replaced 2019 with CRP Automotive Fuel hose dated 01/2019 purchased online at my favorite MB specific online store i will not mention which. Problem arrived when the leaks came from the clamps to each injector here and there so i just tightened each as needed. Now i can visually see the surface of each hose with fine cracked lines just like MMWA you not need to squeeze it to see it. I know for a fact that fuel hoses should be replaced and permeability should be low iam still trying to find a replacement. Hose marking are a start, look for SAE 30R9 working pressure is 100psi & permeability is low. But on your application for non pressure lines a fuel hose SAE30R14 does have a 35psi with low permeability. Good luck 🤞

[@Kridre]

When I was doing my rubber hoses going in to the transmission cooler I used Semperit brand hoses, almost 3 years later there sill look like new. I know fuel and oil are different, but this hose was the most expensive by 1m that I could find locally.

[@fo3]

I got some gates hose from either rockauto/fcpeuro or pelican for my car in Perth. I'm sure something is available locally if looking for e85 or submersible of decent quality though. I replaced engine bay hoses a couple of years ago but ignored the fuel tank to pump ones and chassis line to tank and they started leaking this year, so they all need replacing.

[@theundergroundlairofthesqu9261]

It's been a third of a century. I've changed every cooling hose and I'm halfway to changing every fuel hose. I suppose I should change some brake hoses, too!

[@mb.warehouse_find4221]

My 1995 S124 Estate/Wagon E320 had a big fuel leak underneath by the fuel filter/pump but not coming from there. It seems like it is coming from above the differential housing. Kindly assist by showing a disassembly chart of that fuel tank where leaks may be possible to originate besides the fuel filter/pump assembly area (covered by hard plastic shield). She has 236000 miles on odometer but still want to be driven fast (80 to 105mph) on the grapevine in California

[@jrt2924]

I dont know about australias fuel but atleast in finland i tried to buy hose for the rear pump feed and product book said it's good for pretty much any type of fuel but Retail sellers have noticed that additives or something within fuel causes hoses to fail prematurely althought they are still rated for diesel, regular, e85, methanol in US. Maybe similar issue going for you?

[@lisab3396]

Fuel Hose Specification >> SAE J30R6 You should be able to buy it from any Pro Trucking Repair Business. That hose shown on the car now appears to be Radiator and or Vacuum Grade Hose?

[@MMWA-DAVE]

This wouldnt surprise me. They were told its for fuel too

[@alanOHALAN]

Can you use silicone hoses?

[@chorgesviva]

Regarding the binary code dilemma. Many years ago I visited the production line in Stuttgart on several occasions and I seem to remember that at the start of the journey of the body shell down the line, a code reader scans to code on the slam plate and checks down the line that each individual specific item relating to the car's spec is in place (JIT delivery from outside suppliers). If the components were not already in place, then the body shell didn't start its journey. Hope this helps. Chris

[@MMWA-DAVE]

This makes perfect sense and is very logical. Thanks

[@MMWA-DAVE]

Do you remember if it was simply a stack of pre-punched unique plates which were simply assigned one per chassis, then stamped with appropriate numbers and then manually linked to the individual vehicles VIN using their internal systems for the manufacturing purpose? This is What i’m thinking.

[@chorgesviva]

I don't have actual knowledge of what you suggest but sounds like a typical Mercedes-Benz logical idea. FYI, I have two 124s and find your videos extremely useful.

[@RicardoMartinez-kr5qk]

have you checked out belmetric

[@MMWA-DAVE]

never heard of it, but looks good!

[@RicardoMartinez-kr5qk]

@@MMWA-DAVE ya they hVe a lot of good stuff

[@Wookieboner]

Can you source Cohline brand hoses? Do RHD cars use the same hose parts?

[@MMWA-DAVE]

for the rear it should all be the same. Theres only one variable at the front as far as im aware - the fuel cooler version (Australia has this) and non fuel cooler version.

[@MMWA-DAVE]

on the 103 cars there early and late variation at the rear but m104.980 cars should all be the same at the rear.

[@Wookieboner]

@@MMWA-DAVE I've got a 90 m104 car with the fuel cooler. I had not known these hoses were nla from Mercedes.

[@johnbower5732]

I called my uncle in Germany and had him send me fuel lines for my 84 300sd w126, because the ones here in the states are shit.

[@FordMercGuy]

Argh how annoying brother!! Certainly would hope to last atleast 100,000ks 😪 Would the place that did these for you guarantee their work? Since perhaps it's defects in the manufacture of the hoses across the range of hoses you have?

[@MMWA-DAVE]

all the hoses they made are complete sh*t. Its one of the 2 large hydraulic hose companies in WA. Nothing is as good as genuine MB. Unfortunately more than half are now NLA. Surely someone out there makes complete w124 fuel hose kits, of decent quality.

[@erichammond6434]

ortac 300

[@paramtrx9558]

I would sell you my 94 E420...black on black.. and only you. Thing is, it needs just as much work as the Red 124, and we drive on the wrong side of the road up here.

[@MMWA-DAVE]

LHD is the only option anyway for the v8 w124’s and im ok with that. I have no problem importing LHD car and driving it as is, its legal to do so too when 25 or older. I don’t really want to do a full resto again i just dont have the time anymore.

[@paramtrx9558]

@@MMWA-DAVE It's great to give your passengers a thrill! lol.. it's a 4 speed as we know but there is a fantastic place at the top of 2nd and 3rd.. Way to be awesome at something and be too busy to do it.. like me haha

[@MMWA-DAVE]

@@paramtrx9558 what i have planned for a 420 is to make it a sleeper, the m119 will be exchanged with a modified 5L and way more powerful than a 500 without the risk of harming the value of a rare and valuable car (500) 😃

[@paramtrx9558]

@@MMWA-DAVE It already is a sleeper if you ask me, sounds like a great plan tho.

[@joshuabenson2568]

Use wooden planks or rubber blocks to lift the car on your lift, that way you get more clearance to do the job! By the way, can’t you just use hoses from a completely different car? Only things that matter are diameter, length and the material being suited for your guy’s fuel. Shouldn’t be too hard.