Does anyone have a solution for the 124 501 35 82 hose? Mine last between 2 and 5 years, always blowing at the "T" at the most inopportune time (up a steep mountain in the middle of nowhere, etc.). They rarely "blow", they just pop a leak and so I'm usually able to McGuyver it and limp home but it ruins the day.

My 300d runs at 80-85 degrees C probably 98 percent of the time. It's really rare that I push it up over 100. The combo of a hot day, a/c on, and a mountain pass will do it though. When that happens, pop. I should be able to remember to turn off the AC but I forget.

See the pic below for this part. I envision a stainless steel or aluminum "t" replacing the formed part. Has anyone ever contemplated such a fix? I'd take my current hose which blew at the formed seam (2 yrs old), cut out the formed "T" and give it a whack but I thought if this thing existed somewhere it'd save me finding a fabricator to weld one up for me.

Seems to me a one-time solution for this age-old problem but perhaps I'm the only one with the problem...

If no ideas, does anyone with a reasonable amount of welding experience want to give me a hand with producing such an item? I'll pull the hose and measure the IDs with a caliper and figure out how long the tubes would need to be to reuse the existing cut hose. Just let me know the expected damage once I get you the measurements. I think that either SS or Alum would be fine. Welding a half bead around the circumference of each of the 3 ends would give the hose and clamps some security.

If it works out, perhaps a few others would be interested in purchasing one. If for nothing else, along with the appropriate clamps it'd be a great on-the-fly repair kit to keep in the toolkit or with the spare.

Attached Thumbnails

 

__________________
_____________________________________

Chris_87_300D
1987 300D - 415,000+ miles
1999 E320 - 220,000+ miles
2008 SL55
2019 Sprinter Diesel 4x4

Try a brass barbec t and hose clamps. Just go to hardware store and find right size and some hose clamps. You probably have restriction in line. Where on that hose, does the hole blow

__________________
What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

I'll have a look at the HW store...

It blows right at the T - where the formed piece attaches to the big hose (either at the top or bottom of the formed piece). The small attached hose goes to the overflow tank (dead end) and the big one is the main hose (seems to cool just fine, until it blows). I flushed it recently and everything seemed to flow ok then. I thought that the hose looked pretty good too.

I think that they blow because 1) the formed T design isn't ideal, and 2) lousy aftermarket parts.

From MBZ, this part is about $120. Fastlane has an Elaplast for around $75 which I'd expect is a quality part. All of the others are around $20 - $30 but apparently not worth even that. I like the metal T solution because it eliminates this as a failure point but I'll probably buy one from Fastlane or MBZ and then keep the T as a field service part for when the inevitable happens.

__________________
_____________________________________

Chris_87_300D
1987 300D - 415,000+ miles
1999 E320 - 220,000+ miles
2008 SL55
2019 Sprinter Diesel 4x4

The bigger question is why it's blowing. I've had my car to and a tick over 100*C on the gauge without popping the cooling system. Maybe your pressure cap isn't releasing system pressure above 1.4 bar as it should. BTW, that reservoir isn't an overflow tank since it's part of the pressurized system. There is an overflow tank in the right fender behind the wheel well liner.

Sixto
87 300D^2

Great point - I'll pick up a new cap. Should of thought of that one already.

BTW, does anyone know the part #s for (87 300D 603):

1) the 20cm/8.5" L shaped hose from the solenoid valve (by the battery) to the metal pipe that runs under the expansion tank and into the engine compartment [it's not very clear but it looks to have 124 832 53 94 printed on it - confirmed valid part #] and,

2) from the other end of the same metal pipe (by the turbo), the 25cm/10" U shaped hose from the pipe to the block [looks to have 124 832 54 94 embossed on it - confirmed to have been superseded by 124 832 81 94].

Absolutely correct on the pressure tank (got lazy in my description) but I didn't know that there was a real overflow...I thought it just spilled out back there. It's probably full of putrid goo. I'd better clean that out.

__________________
_____________________________________

Chris_87_300D
1987 300D - 415,000+ miles
1999 E320 - 220,000+ miles
2008 SL55
2019 Sprinter Diesel 4x4

X2 I've had mine to 110 (climbing a pass, A/C on 4 bikes on roof rack) and the hose didn't blow. I don't think that it has ever been replaced on my car. I'm sure it is over due.

How many times have you blown the same hose?

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

I'm on my 3rd. First time that I'm aware that it was changed was in 2005 (OE part w/ part # stamped on it, lasted 18 yrs), I replaced it with aftermarket. 1st aftermarket lasted 2 yrs. Looked for better aftermarket due to OE cost (that one lasted 5 yrs.) All three have blown in the same place and the rest of the hose looks good, which led me to think about a design flaw. No bloating, etc.

No obvious pressure issues in terms of head gasket leaks (coolant is perfectly clear, no bubbles coming in to the expansion tank that I've ever seen, no oil in the coolant, exhaust gas test came up negative a while back).

Also, it doesn't blow every time it goes > 110*C but that's when it does go. In Texas summer heat it used to almost touch the red line around 120*C pretty regularly but I solved that problem eventually with a new radiator. That might have killed the first aftermarket hose. The cap is a great, cheap place to start.

Sounds like this isn't a pervasive problem out there. New cap and avoid the cheap aftermarket parts and I should be back in the game. Thanks to all.

__________________
_____________________________________

Chris_87_300D
1987 300D - 415,000+ miles
1999 E320 - 220,000+ miles
2008 SL55
2019 Sprinter Diesel 4x4