Steel Hard Line Failure

[baggio421]

My brake pedal sank to the floor last week while driving under normal conditions. Narrowly avoided an accident. Brake fluid was pouring out from under the car in front of the drivers side rear wheel after I finally got it parked.
I was able to get the car up on jack stands last night to assess the situation. After further inspection, the steel hard lines running underneath the car are in bad shape. It seems that one of the lines running up to the front wheels ruptured while I was applying the brake. My "head mechanic" best friend looked at the lines and said all of them should be replaced. Not to sweet. All four lines coming out of the small box near the drivers side rear wheel well are completely rusted. Touching them slightly causes pieces to fall off.
After searching threads on this site and over the net I was unable to find anything relating to the procedure for replacing the lines. I have obtained a metal tube cutter, tube bender, and ISO flare kit. The only place I could find steel brake lines was NAPA. I figure they will probably have the nuts and fittings I will need as well. I have sprayed all the connectors that I could see with Blaster. I'm planning on doing that one more time today because everything is so rusted underneath.
My only questions are what is the factory diameter of the steel brake lines, are there any other special tools I will need, are there any tips on where to start and what not to do?
It seems to me this is a rare problem SHO owners will ever have to tackle. Any insight or suggestions would be much appreciated. Thank You.

 

[awb85]

I just spliced mine earlier this year (bought the car in Jan.). It's not too bad. Both of mine went (same area: a friend of mine who use to have a taurus had them rust out in the same place twice!).

It's not that bad of a job. However, I suggest either borrowing or buying a tube bender, as it is well worth it. There cars use an ISO flare, as opposed to a Double flare, so make sure you buy/rent the correct kit. If you decide to splice, buy brake line with the ISO flare already on it (3/16" line). This way you can use an SAE flare kit for the union (mine are by the rear drivers side door). The ISO flaring is a PINTA — the hardened steel lines don't like to "bubble."
You know that valve box in the rear? You'll probably have to use the threaded fittings from the old break line — I couldn't find new ones that would fit.

If you splice, you only have to flare one end of the line you buy, and can leave a factory flare on one end.

As to replacing the entire length? I wouldn't want to do it — unless the entire tube looked rusted, as if it might burst in the near future.

Good luck with what ever you do :thumbs_u:

 

[awb85]

OOOPS!

I skipped half of your paragraph

I was talking about the lines running from the front of the car to the distribution box — you're talking about the lines from the box to the break hoses.

I also read that you already bought everything — if you already have an ISO kit, don't worry, it's not that bad. (I just had to use lengths of 1" and 1/2" copper pipe between 1 and 2 feet long to increase leverage — there came a point where the handle became extremely difficult to turn. As I said, its hardened steel).

Yes, replace all four. They're not that long. And yes, hopefully NAPA will have what you need — I had horrible luck (and service) at a chain, so I used small local stores instead — they had exactly what i need.

It's 3/16" (also 4.75mm I think) break line. Be careful when buying unions — as there's two thread styles that are SLIGHTLY different sizes. Try threading the lines into the unions at the store to make sure they fit tight without ANY looseness.

Good Luck! I'll check back.

 

[baggio421]

Thanks for the tips and info. I went to the library yesterday and the 93 service manual had been returned. I did some reading last night and found a lot of useful information. I'm going to start pulling the lines out today. I'll let you know how things go. Unfortunately I'm going to have to replace the lines completely. They're so rusted and crumbling I don't want to have to do things twice.
Thanks again for the info.

 

[awb85]

In that case, one more thing I had to do is:

When forming the ISO flare I had excess squeeze out around the outer edge that prevented the line from fiting properly into a union and/or end fittings.
To get around this, I simply filed down the ridge enought to make things go together — it didn't have to be perfect.

Good Luck!

PS: Remember not to let the master cylinder run empty when bleeding. O, with this:

Mine inevitably drained since the rear lines were cut for my work to be done. My Chilton's manuel had directions on bleeding the master cylinder which seemed to work. Consisted of filling it with break fluid (Need 2 people here)
1. Then with a rag in the engine compartment under the fittings on the MC, open the rear line 1 or 2 turns
2. Have someone inside press down the break pedal. You'll see a little fluid and bubbles coming out around the threads.
3. Close the fitting, have your friend release the pedal.

You just repeat this operation until see not so many bubbles escaping (ie: the air is out). I wasn't too finicky about the bubbles — just went for a big reduction myself ( was taking too long for me at that point!!).

 

[algae]

replaced my rear lines recently. I found that each line is 10 feet long, so I saved the fittings, bought a 25 foot roll of 3/16 line and had alocal shop do the flaring. Installing the lines was a snap, the only problem is I forgot to take note of which line was which - something I'll sort out soon!!

algae

 

[93redATX]

Did this last year (in the middle of winter, no less). It was a PITA, simply because I couldn't find the right materials (read:fittings. Gave up and used the old ones, even though they were pretty beat up). Replaced the two lines that run from the front of the car to the rear distribution block. The hardest part as far as the bends go was a strange contortion the line goes through at the rear of the car; other than that it wasn't too bad.

Of course, freezing temperatures and having rust fall into your face made the experience thoroughly unenjoyable

 

[awb85]

a flare nut wrench works best on those brass fittings — it can be worth buying the correct metric size from your local store.

 

[baggio421]

Thanks to everyone for your insight and information, it came in handy for the repair job.
Sorry I haven't posted in a few days, been super busy.

The hard line repair was a success. My buddy and I replaced the lines from the rear distribution box to the front distribution box. Getting the lines out was not to bad. We had to be careful not to break any of the black plastic line holders. The only bad part of the job was the amount of rust falling into my hair and face. You'll have that from northern ohio winters and a previous owner who did not take good care of the car.
So, the line came out pretty easy. I could not believe how rusted the line was. It was falling apart from just touching it. We purchased new line, line couplers, and new fittings for the distribution box from Napa. It was nice cause the line we purchased from napa was already flared. We purchased about 10 ft for each line. The fittings for the distribution box were like 6 bucks apiece. The front fittings are smaller than the rear fittings. Remember that if you ever need to do this job.
Bending the line and hooking up the couplers wasn't too bad. Make sure you tighten everything nice and good. We had a few leaks during bleeding but made them go away with a few more turns. All in all it was not that bad, especially not having to flare and cut any lines. The guys at Napa were really helpful and new exactly what I needed.
Thanks again for everyones help. Now on to the next problem, the tranny.

 

[Yamaha V6]

FYI, for the record (as I found out recently)...

The rear distribution block is discontinued, no replacement listed. I got one off a locator service dealership in the area, luckily.

 

[Denny]

What if some dude took out that rear box before you ever got the car?

 

[Yamaha V6]

Then you have full brakes in the back, instead of proportional depending on the suspension load.

 

[Denny]

Then you have full brakes in the back, instead of proportional depending on the suspension load.

Is this a good or bad thing then?

 

[shonole]

Is this a good or bad thing then?

Yeah, is it?

 

[ViPER1313]

Has anyone had all new lines installed by a shop? What is a reasonable price for this job. My friends SHO just failed inspection for rusted hard lines running above the gas tank and up front near the master cylinder......