Funny, didn't think that would leak

[blitzkraig]

I purchased some stainless hydraulic lines from MSA, including one for the clutch. While I went to start my car when I was swapping carbs I noticed some smoking by the battery. I ran around with extinguisher in hand and saw smoke coming from a now burst and leaking clutch hose. This is what I found.

The plastic spurting out of the steel braiding makes it seem like there was too much pressure (doubt that's the problem). Some of the rubber at the end melted onto the hose. So that and the smoking makes be believe it was way too hot. But the car had been cooling down from running for 1/2 an hour. My only guess is that somehow there was electric current going through it? Any other ideas while I'm waiting for a replacement hose from MSA?

[Bambikiller240]

Originally posted by blitzkraig

I purchased some stainless hydraulic lines from MSA, including one for the clutch. While I went to start my car when I was swapping carbs I noticed some smoking by the battery. I ran around with extinguisher in hand and saw smoke coming from a now burst and leaking clutch hose. This is what I found.

The plastic spurting out of the steel braiding makes it seem like there was too much pressure (doubt that's the problem). Some of the rubber at the end melted onto the hose. So that and the smoking makes be believe it was way too hot. But the car had been cooling down from running for 1/2 an hour. My only guess is that somehow there was electric current going through it? Any other ideas while I'm waiting for a replacement hose from MSA?

Holy Schmoley! I can't imagine how the hose could get hot enough to fail. What would impart the heat? The exhaust system doesn't come close to the location of the hose on "normal" Z cars. Is is possible that the positive battery cable came into contact with the clutch hose and caused a short?

I could imagine the hose failing and squirting fliud onto the exhaust system. Is that a possiblity?

Let us know if you figure out the root cause of the failure. I have one of those S/S clutch hoses awaiting installation, but now I'm wanting to wait in case there is a reason for me not to do so.

[2ManyZs]

Only two things I can think of on that side of the engine that might have caused it.. either it was rubbing against the battery cable, or could it have been running against the starter?

It doesn't look like it's any longer than the stock one, but if it is longer, that's all I can think of. Or else it was just a faulty hose to begin with....

[blitzkraig]

Yeah I'm really puzzled by it as well. I've been staring in the engine compartment for about an hour trying to think of what could have done it. I'm guessing my best bet is that it had electrical current going through it based on the smoking and burned rubber. However, the battery nor the starter wires come anywhere near it! I'll look at it again tomorrow when I wire up a relay system for my headlights, maybe I've had a blindspot in my vision today. Anyway, is there any good reason why all my stainless braided lines had 'FOR OFF ROAD USE ONLY' stickers on em?

[tanny]

It does sound like somehow it shorted on a positive electrical source to get hot enough to smoke, unless your exhaust runs really close to it or you were welding on something nearby. As for the "for off road use only", the Forest Service uses Zs with flaming clutch hoses to start controlled burns. Seriously, this is an interesting post and I hope you figure it out before the new hose goes on. Victor.

[mdbrandy]

Do you have all the ground wires from the harness attached to the appropriate places on the car body? On mine, I think that's only the screw on the main harness as it goes along the frame rail a bit forward from the battery, and then the negative battery terminal to the firewall. Oh, and battery terminals themselves from the battery to the engine. If the smaller ones weren't connected, then could all the car's systems that aren't engine related have been passing their current back through the clutch hose and to the negative battery side that way?

I haven't looked at a schematic to see if there's any other path. Just a thought.

[Daniel]

It s sounds like a ground issue.If it was a positive short it would burn fast and loud like hitting the jumper cable ends together.If you go from battery neg to the motor you should have 0 volts.Then check to frame /battery and then motor/frame.The hose was acting as a wire.My guess is that a meter placed between the connections where the stainless lived will read 12v

[Bambikiller240]

Originally posted by blitzkraig

Yeah I'm really puzzled by it as well. I've been staring in the engine compartment for about an hour trying to think of what could have done it. I'm guessing my best bet is that it had electrical current going through it based on the smoking and burned rubber. However, the battery nor the starter wires come anywhere near it! I'll look at it again tomorrow when I wire up a relay system for my headlights, maybe I've had a blindspot in my vision today. Anyway, is there any good reason why all my stainless braided lines had 'FOR OFF ROAD USE ONLY' stickers on em?

If Electrical current is involved, you should see arc/burn marks on the S/S hose from the point of contact with the electrical system. If no arc marks are seen, I would suspect a defective hose and the smoke caused by fluid spraying the exhaust. If the fluid caught fire, it might melt the hose material.

The reason for the "OFF ROAD USE ONLY" stickers is that the hoses have not be subjected to Department of Transportation mandated tests. As it has been explained to me, the parts have not been submitted for the "Whip test" required for parts used on public highways. Some other manufacturers do submit their S/S hoses for DOT certification. My S/S brake hoses are not DOT certified but they have worked flawlessly for over 4 years.

[2ManyZs]

Uh Carl... how's the fluid going to get on the exhaust? Wrong side remember?

I'd say it was acting as a ground....... which isn't any better than it having direct current involved....

[Bambikiller240]

Originally posted by 2ManyZs

Uh Carl... how's the fluid going to get on the exhaust? Wrong side remember?

I'd say it was acting as a ground....... which isn't any better than it having direct current involved....

Yes, wrong side, but fluid under pressure can squirt some distance. Admittedly a W.A.G.

As you'all know, I don't understand electrical stuff too well but wouldn't there be some other indication of an electrical problem, like something not working, amp guage needle deflecting, melting of wiring (which should be more fragile than the S/S hose?

[blitzkraig]

Got my new clutch hose in last night. I've been having trouble with the car starting right away so I changed where the negative cable from the battery bolts to the firewall and now it starts great. I'm also not reading any voltage going through the clutch hose. I don't really feel like moving the negative cable back to see if it was the problem. I'm guessing that when I was trying to get the car started that one time, the current was trying to find a better way to ground and the clutch hose turned out to be easiest for it for some reason. Anyway, back on the road again!:cheeky:

[blitzkraig]

It happened again.

After a frustrating day at work I came home to investigate. I had been having the bad ground problem again and when I went to start the car this morning with the clutch pedal out the hose fried. I tested it for voltage tonight and didn't read anything off it but it got awfully hot when my girlfriend tried to start the car. Anyway, I've ordered a new hose again and bought a new ground cable which is now grounded thoroughly by a bolt to the engine block through the bellhousing. Just curious though, where do you guys connect the ground cable for your battery?