Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: ctaylor738 on September 24, 2022, 01:35:33

Title: Injection Line Repair
Post by: ctaylor738 on September 24, 2022, 01:35:33

I was troubleshooting a puzzling fuel flow problem on my 230SL.  Grasping at straws, I wanted to remove the pipe from the fuel filter to the injection pump to test it for obstruction.  When I tried to loosen the swivel nut on the cold start valve connection, the male fitting on the pipe broke off.  Most of the fitting remained in the swivel nut on the CSV line.  I removed the CSV line and buggered the cone nipple trying to remove the remains of the pipe's fitting.  I was able to save the swivel nut.

Replacement CSV lines are available for around $150 plus shipping, which would require a giant box.

So I found replacement cone nipples for $1.99 on Belmetric.

https://belmetric.com/solder-cone-nipple-uncoated-plain-steel-cohline-series-9010/

Belmetric also has swivel nuts.

I cut the CSV line close to the end, and filed off the remains of the brazing of the nipple to the line until he replacement cone nipple would slide over the line.  Then I cleaned both pieces with acetone, applied flux, and soldered the cone nipple to the pipe with plain old plumbing solder.  Cleanliness is key here.

I installed a new filter-to-pump pipe that Gernold supplied and reinstalled the CSV line and went on about my troubleshooting.  The problem seems to have been a weak fuel pump but with some strange symptoms that I may put in another Topic.

Anyway, this is an option if you need to repair a line or fabricate a new one.  Steel fuel line is available in various metric diameters online and at parts stores.

Picture of repaired line attached.

Cheers,

CT

Title: Re: Injection Line Repair
Post by: Kevkeller on September 24, 2022, 02:51:10

Thanks for the info.

Title: Re: Injection Line Repair
Post by: AndrewB on September 24, 2022, 10:13:07

Well done !

Title: Re: Injection Line Repair
Post by: stickandrudderman on September 24, 2022, 10:45:58

I think I'd be happier brazing rather than soldering.

Title: Re: Injection Line Repair
Post by: ctaylor738 on September 24, 2022, 13:03:17

Yes, so would I.  Definitely if doing this on the high pressure side of the pump.

But I have yet to find a shop that will take small jobs in the DC area.

And soldering with copper pipe is widely used for water supplies.  Household water (including ours) is around 50 psi.  I measured 9 psi coming out of the fuel filter.

The heated joint really pulled the solder in nicely, so I feel pretty good about the repair.

Cheers,

CT