SL/R230: ABC Hose Clarification
Thread Starter
Newbie
Joined: Jun 2020
Posts: 8
Likes: 1
From: San Diego, CA
2005 SL500, 2008 CLK350, 2013 S550 Weistec
ABC Hose Clarification
Hey Team,
I had a high pressure ABC hose burst on a car I just bought. I have ordered a remanufactured hose with a fitting from rebulidmastertech, fitted the whole thing back, primed the pump and when I started the car the fitting shot off again. It seems to me this hose goes from the left side of the front pressure valve block to the engine bay, behind firewall and then disappears towards the rear. Most surefire way to identify it is looking through the left front wheel well, there are 3 horizontal running high pressure hoses and this is the top one. Tried looking at abc diagrams but they are confusing as they show this hose to be the middle one. Anyway, I'm just trying to figure out what it does and where it goes (and which direction it flows) as I may just suck at fitting plumbing together but I might have an underlying issue like a clog or something. The car wasn't driven throughout this whole ordeal so I would rule out a bursting accumulator. Any help is much appreciated, can't wait to take this baby for a drive finally. Thank you!
I had a high pressure ABC hose burst on a car I just bought. I have ordered a remanufactured hose with a fitting from rebulidmastertech, fitted the whole thing back, primed the pump and when I started the car the fitting shot off again. It seems to me this hose goes from the left side of the front pressure valve block to the engine bay, behind firewall and then disappears towards the rear. Most surefire way to identify it is looking through the left front wheel well, there are 3 horizontal running high pressure hoses and this is the top one. Tried looking at abc diagrams but they are confusing as they show this hose to be the middle one. Anyway, I'm just trying to figure out what it does and where it goes (and which direction it flows) as I may just suck at fitting plumbing together but I might have an underlying issue like a clog or something. The car wasn't driven throughout this whole ordeal so I would rule out a bursting accumulator. Any help is much appreciated, can't wait to take this baby for a drive finally. Thank you!
Super Member
Joined: Sep 2018
Posts: 746
Likes: 185
From: Melbourne, Australia
2005 SL 500 R230
Pictures, please. And a shot of the fitting where it blew off. Most likely it's a mistake with a fitting or how the hose was fitted back.
The system runs at very high pressure so it all has to be up to the demands of around 3000 psi.
Blown accumulators can lodge bits of rubber in the pipes, but that would be unusual. Send photos.
The system runs at very high pressure so it all has to be up to the demands of around 3000 psi.
Blown accumulators can lodge bits of rubber in the pipes, but that would be unusual. Send photos.
MBWorld Fanatic!
Joined: Aug 2020
Posts: 1,329
Likes: 365
From: Gretna, NE
'03 SL55 Black, '03 SL500's Aegean, Mars Red, Tazanite, Alabaster, '11 S550 Flint Gray
The two lines closest to the engine, FB1 and FB2 are the struts. The first line 'around the corner' by the wheel is the pressure feed, which is the one you are talking about I believe. That line will dead head in the block when the blocking valves are closed. Any excess pressure would be from a faulty pressure regulating valve. A compression fitting blowing off is normally an installation issue. Did you remove paint and do you have grooves where the bite fittings dug in?
MBWorld Fanatic!
Joined: Aug 2020
Posts: 1,329
Likes: 365
From: Gretna, NE
'03 SL55 Black, '03 SL500's Aegean, Mars Red, Tazanite, Alabaster, '11 S550 Flint Gray
@MikeJ65 Should you remove the paint from the pipe before applying the compression fitting?
Thread Starter
Newbie
Joined: Jun 2020
Posts: 8
Likes: 1
From: San Diego, CA
2005 SL500, 2008 CLK350, 2013 S550 Weistec
Well gentlemen, I tried my best to remove all paint and to make sure that the cut end of the pressure pipe is as straight and clean as possible. Since the fitting is a bit fat it's pretty awkward to manuever the two hose bits perfectly parallel, but I did my best. As for the actual hose, it comes out the side of the valve block, and it's the one closest to the wheel, so it would be the rear one. I believe it's called something like pressure hose going to separation point on floor, and it goes to the rear valve block. I have no clue if it's a feed or a return line though. I'm starting to get tired of having a hundred dollars of pentosin spilled on my floor with each try though, so any advice would be very appreciated.
Also, there was no biting surface, I have a single stainless steel ferrule that slides on the end of the hose but it won't let the hose fully though, it's like there's this stop (or groove, sorry, second language, tricky concept) inside that makes it work like a hat with a hole on the top but it won't slide on past this 'stop'.
Also, there was no biting surface, I have a single stainless steel ferrule that slides on the end of the hose but it won't let the hose fully though, it's like there's this stop (or groove, sorry, second language, tricky concept) inside that makes it work like a hat with a hole on the top but it won't slide on past this 'stop'.
Trending Topics
MBWorld Fanatic!
Joined: Aug 2020
Posts: 1,329
Likes: 365
From: Gretna, NE
'03 SL55 Black, '03 SL500's Aegean, Mars Red, Tazanite, Alabaster, '11 S550 Flint Gray
If you are saying that the tube doesn't go completely through the ferrule, that is a problem. The tube should push completely through the ferrule and extend roughly half the tube diameter past it. You might have to deburr the end a bit better to get it on.
Once tightened, the ferrule should not be removable. You can pretighten each side, check the ferrules, and then reassemble.
Once tightened, the ferrule should not be removable. You can pretighten each side, check the ferrules, and then reassemble.
MB World Stories
The Best of Mercedes & AMG
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)
Verdad Gallardo
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
Thread Starter
Newbie
Joined: Jun 2020
Posts: 8
Likes: 1
From: San Diego, CA
2005 SL500, 2008 CLK350, 2013 S550 Weistec
Hey all,
I have successfully fixed the problem. Turns out I just got a ferrule one size too small. A $9 trip to Grainger and she's all fixed now! I used a 10mm twin ferrule that had to be purchased separately but hey it fixed it. As for rebuildmastertech's customer support I am less than happy, it's good to see my baby on her wheels again though.
Thanks again for all the help!
I have successfully fixed the problem. Turns out I just got a ferrule one size too small. A $9 trip to Grainger and she's all fixed now! I used a 10mm twin ferrule that had to be purchased separately but hey it fixed it. As for rebuildmastertech's customer support I am less than happy, it's good to see my baby on her wheels again though.
Thanks again for all the help!
