Hard brake line repair/replace?
 

Folks,

I am in the midst of repairing rusted out fuel lines on the '85. While doing this I noticed the long rear hard brake line is badly rusted in small spots. It is not leaking, and the brakes work fine.

I am planning to POR-15 the small areas and put it back together.

OR

Can I put in a 6 inch hard line patch somehow with compression fittings? I dont want to replace the whole thing. Im already having too much fun with the fuel lines.

OR

Am I being a moron for not replacing the entire long length?

I think Im starting to go crazy with the rust related repairs. Never again will I buy a 123 from the rust belt.

dd

I think SAE requires flared fittings but personally from a technical standpoint, I would use stainless steel Swagelok fittings or similar.

I think they relaxed that requirement on rear brakes.

I would replace as much as seems like it is rusted. Check all the mounts for rust issues. Also, I would use flare fittings, no need for extra expense.

Don't use compression fittings! They probably won't burst on you, but they may squeeze the line enough to impede flow (ask me how I know).

Replacement Euro brake lines are available at AutoZone. If you want to patch, you can buy short lengths from AZ, the unions are available at Napa and the bubble flare tool is available from eBay.

They also sell the "Bubble" Flaring kits. I bought one several months ago it was about $24 from one of the Ebay Sellers and while a China Import is marketed by the too company OTC.

They may be available from the local autoparts but I did not look.

The best pic I could find on short notice:

Generic brake line from Autozone is very cheap. Potentially wrecking your car due to a half a$$ repair is expensive. Spend less than $10 and fix it right.

Scott

p.s. Autozone also rents the bending tool for free ($5 or so refundable deposit)

dieseldan,

i did the brake lines myself with a bending tool which I eventually did not use so much as well as the flaring tool. in the pictures posted above, i dont believe they are correctly labeled. its either single flare or double flare. possibly the hardest part is bending the lines that go outwards from the T-valve to the brake/hub area. might be different from your vehicle, but on my 300D Turbo, watch out, lots of bends on the road...

Best thing to bend them with the original taped side by side. And oh, practice like nobody's business. And probably the most key of all key tips: before you crimp the end, please make sure you put on the nut! because once you flare it and unless you cut it extra long, you're out of luck. You'll have to bend the whole thing again.

here are 2 links I collected along the way that helped:

http://www.pharmacy.arizona.edu/staff/wunz/NoABSTCS/DoubleFlare.html
http://www.carcraft.com/howto/50919/index.html

thanks guys. i should replace that line. i think i knew it all along.

trouble is that it's a nightmare to replace that 10' line back to the rear without a lift. i may limp this one over to the indy to do. id think with a lift and their skills they'd be able to patch it up very quickly and not cost too much.

dd

If they try and charge a lot find somewhere else. I had the lines replaced about a year ago and from what I remember the price was minor.

True enough. Lines are a PITA, but really not that time consuming on a lift.
But, if you can do the fuel lines, the brake line will seem easy, especially now that you've had practice....:D

DD,

I would replace the whole length. I tried patching in a piece with flare kit and could not get it so seal after many tries.

Paul

What if you DON'T have a lift? It looks like I'll need to replace mine. I do have jack stands, but even with those, it's not easy to manuever under the car and those rear brake lines don't look very easy to get to.

I don't think I'd want to try patching something like brake lines. I guess the hard lines run all the way from the master cylinder to where they attach to the hoses?

A Mercedes mechanic I spoke to last week told me that you have to drop the rear subframe assembly out to get to the brake lines. Is this true? If so, how does that work exactly? I see what he means because there is a joint from the main F-B line to the L-R lines which seems to be concealed by the subframe.