Installing new rear brake line on 87 TR

[tom h]

The inverted flare nut on my rear brake line (where it meets the flex tube to the rear axle) is mangled, http://www.turbobuick.com/forums/showthread.php?s=&threadid=81693&highlight=original , and among my several options I'd ideally prefer just to replace the entire line.

Assuming I have a correctly bent rear brake line (either GM original, or reproduction from Classic Tube or Inline Tube),

-- is it even possible to replace the entire rear line with the body still on the frame?? (some of the tubing retainer clips, have hold-down screws which appear nearly impossible to re-install, even if I can get them off).

-- Or is a tube union somewhere likely to be necessary?

-- And even if spliced, is it possible to "snake in" the rear portion of the brake line?? (The car is about 18" off the ground, but I cannot get it higher, nor can I get it to a lift in its present state)

 

[Jimn8or]

Do what you need to do to replace the line first. Next worry about hold-downs all being in the oem location. Last, DO NOT put a cheesy, or expensive, brass-joinery block in your brake system...this is simply looking for serious trouble some day down the road...for example if they fail and you hit someone and the insurance people find that brass block joiner in there, you will work for the rest of your life, to pay whoever you hit.
Some things on these cars are buggers to do right and some are not. The former far exceeds the latter. If in doubt, take it to a shop and pay them $100[?] to do it right.
My 2/5's of a dime.
Jim

 

[tom h]

Originally posted by Jimn8or
...Last, DO NOT put a cheesy, or expensive, brass-joinery block in your brake system...this is simply looking for serious trouble some day down the road...

If I absolutely had to, I'd consider a Swagelok steel tube union, it's special 2-ferrule design is vibration proof and the pressure rating of the joint exceeds the burst pressure of the tubing itself. But I'd rather not ... prefer to keep it "factory" looking.

My main concern is I maybe able to somehow extract the old tube ... but will I be able to get a new piece in? Especially if want to use a single length, and if the car height is restricted to about 18" off the ground (may not provide enough clearance to "roll" the tubing into position, but am not really sure).

 

[tom h]

well, I went ahead and ordered a replacement rear brake line from Inline Tube for $70, in Stainless Steel (OEM steel was $50).

Looks like it will be a PITA to replace, but will post back in a couple weeks ...

for sure, I will use a bit of anti-seize on the male nut threads, no way do I ever want this to happen again!

 

[jshilli1]

Its possible to install it all in one piece. The hard part is where it goes through the little hole right where it joins to the flex tube at the axle- the rest is easy! The only issue I found is it is nearly impossible to unbolt the tube clamp next to the crossmember because the bushing will not allow you to get a wrench in there- I trimmed off some of the rubber with a razor blade to make room for a socket.

 

[bruce]

I just replaced all my lines, and used the SS version from PST.

Couple really minor tweaks to get it to fit, and being SS not gonna have to worry about rust.
Also did the Russell AN Flex lines.

 

[tom h]

Originally posted by jshilli1
... The only issue I found is it is nearly impossible to unbolt the tube clamp next to the crossmember because the bushing will not allow you to get a wrench in there- I trimmed off some of the rubber with a razor blade to make room for a socket.

Which cross-memeber is this? If it's the transmission support cross member, I've had it off before, so removing it to gain access is do-able, just adds another hour or so to the job.

I'm already expecting this to be an all-day job!

 

[jshilli1]

Yes, its the tranny crossmember. Basically you cant get a socket on the bolt because the bushing is in the way. I don't think slicing off the corner of the bushing will hurt mine in any way- there's still like 2 1/2" square of bushing.

 

[Graham Hantz]

3 section replacement, inexpensive

Hi Tom,

Just wanted to let you know that I replaced the line from proportioning valve in front to just above the flexible tubing. I was able to use all the orig. hold-downs except for the one near the front DS wheel-well. If you'd want to know how I broke up the line to accommodate for the tight fit, let me know. I actually kept the patterns I used to pre-bend the tubing. I used over-the-counter replacement lengths and also didn't have much clearance off of the floor.

Best wishes,
Graham <graham.hantz@uscm.org>

 

[tom h]

This past weekend I succesfully replaced the rear brake line ... but what a PITA !

I used the Inline Tube S.S. line, it's a good fit & recommended. It needed just a tiny bit of hand bending to mate squarely to my new brass Combination Valve in front.

Oddly, the hardest part was removing the old line. I tried to remove it one piece, so I could figure out the "trick" in installing the new line, but kept encountering frustrations. I couldn't figure out how to remove the rearmost portion of old brake line, the portion behind the fuel filter.

I removed the transmission cross member to provide more removal clearance, but in hindsight that probably wasn't necessary.

In desperation I cut off the old line, near the fuel filter, and then it was fairly obvious how to remove the rearmost portion of the old line. Although it looked like it was folded in place like a knot or pretzel, by sliding the fragment of the old line forward, it came out. I hurried up and placed the new line in place, before I forgot how to do it!

Put the rear portion of new line into place first, then the front portion is easy.

I was able to get all the original tube clamps re-installed except for the one just rearward of the combination valve ... I think the lines will be fine without this one clamp.

Tips for anyone planning to do the job:

-- There are 5 tube-to-frame clamps to remove. The self-threading bolt is 13mm.

-- My old brake line was mostly dry, so not much fluid dripped out. To avoid a big mess, blow out the old line or temporarily install 1/4" Inverted Flare plugs.

-- Put a tiny bit of anti-seize on the male nut threads, but careful not to contaminate the inside of the line. A seized & damaged nut is why I had to do this @#% job in the first place.

-- If you're middle-aged, take 3-4 Ibuprofen tablets BEFORE starting the job . I was really sore from contorting my arms, shoulders, and head into weird angles, while laying on my back. A lift would've been nice, but the job can be done on 15"-18" jackstands.

 

[QuickWrench]

Just an FYI for those of you doing brake-line splicing...

On the rare occasion that you MUST splice the line, and not replace it (i.e. Line Lock, etc.), I agree wholeheartedly with Jimn8or...do NOT use a brass union.

Parker-Hannifin manufactures steel versions of the union pieces that will fit our application, and I've used them successfully on a couple of different TR's without incident. The components can be purchased through McMaster-Carr, and aren't too highly priced.

In my case, when installing a brake-jumper setup for maximum rear brake pressure, the line pressure can rise above 2,000psi. This could easily cause brass fittings to explode. The steel units are rated at over 5,000 psi...no WAY you're going to break them, and they won't round-off like brass if you have to remove them later.

Just my 0.02. 'later