Help -- ruptured power steering pipe in Mobile, AL

[rv_safetyman]

Tom C, thanks for correcting me.  I am not at home, and did not have reference material with me, so I guessed at 2000 PSI (should have said it was a guess.

Trying to repair the tube in some manner would be my last choice.  If it is leaking, then its structure is compromised. We are talking about some pretty high pressures at times and a compromised tube makes the system vulnerable to another failure Even with the hose connected to it, it surely must be feeling some bending forces.  Replacing it with hose would be my first choice.

Jim

[luvrbus]

Repairs are done daily on heavy equipment with clamps,silver solider,brazing and compression fittings 2500 psi is nothing compared to some of those systems you guys get too complicated for me sometimes lol.

For me if a welder can reach it braze the sucker up and go on down the road it will last forever,like my friend Joe says why pole vault over a ant hill


good luck  

[white-eagle]

i looked up that morris coupling the Clifford mentioned.  that looks to me to be a good way to cover a hole and last forever, or at least until you get somewhere that can do a better job if needed.

driving doesn't sound like a good option, so i'd look into the forklift repair idea.

Make sure you let us know, please, what worked for you.  We pulled our engine last spring and (knock on wood) have not issues, but i'm interested in the solution you found.

[rv_safetyman]

Clifford, as usual, your solutions are pretty practical.  Since you were involved a bunch with construction equipment, I will defer to your approach.

The area where I would be concerned would be where the pipe had a fatigue crack - especially if it was close to the fitting/coupling.  This failure was wear, not fatigue and I think brazing it might not be a bad idea.

Like Tom, I looked up the Morris coupling.  I assume we are talking about this one:

http://www.morriscoupling.com/pdfs/Compression%20Couplings.pdf

I did not see a pressure rating for this system.  I would wonder if it would work because to the tight space and bend.

Jim

[Sean]

Folks, it looks like I have been less than clear about what I need, so let me add a few things.

First off, there is no way to take the pipe out to bring it with me anyplace.  It's 25' or so long and runs all the way to the area of the steering box.  None of that chase is accessible any longer, at least not without disassembling half the coach.  The repair will have to be made in-place, by which I mean squatting in a tight space above the tranny, accessible only by a hatch under the bed.  Even cutting the pipe off square is going to be a challenge.  Getting a welder or even a brazing torch anywhere near the actual cut is probably impossible.

I would love to just clamp something on it, but the break is in the middle of the bend.  As I understand it, these patches such as the Morris coupling Clifford has offered only work on straight sections, so that option is out.  Here is my best attempt at a photo of the cut, by lifting the pipe and getting the camera behind it.  It's a lateral groove, almost like someone went after it with a triangular file:



To be clear, I am not the least bit concerned about the hose or any fittings beyond the hard pipe.  I know where the Parker Store is and I am certain that they can make me a longer hose with the correct fittings.  My only concern here is how to repair the hard tubing itself.

After a bit of research, it appears there is a type of fitting made for this tubing called a "cut ring fitting", and it's even possible that the fitting on there now is of such a type.  If so, it might be reusable.  That said, I am not comfortable with my own skill and equipment in this realm to do the work.

As it happens, we are parked at a boat yard, and I had the yard guys come look at it.  They don't have fittings or tools for metric pipe (the OD is 22mm) but they have called their forklift service for me.  I am hoping they will have what I need and that their technician is small enough to squeeze down in there and do the work.

That said, I am still open to further suggestions, up to and including any sort of temporary repair that would hold enough pressure for long enough to get me to a proper shop.

Thanks, everyone.

-Sean
http://OurOdyssey.BlogSpot.com

[Seayfam]

If you can't get it fixed right there, it looks like you have enough room to cut a piece of hose to slip over the pipe, then you can use a hose clamp right over the damaged area. Screw that down tight and you will be good for a few miles. It should get you to a shop.

[Lee Bradley]

If that pipe is like the pressure pipe on my Neoplan, it is flared stainless steel. I had a piece shortened at a hydraulic shop and it is almost impossible to flare that size SS. The factory heats it red hot and then rolls in the flare. If you can find a compression fitting for that pipe, I would install it at the first accessible spot beyond the bend and replace that section with 4,000 or 5,000 psi hose.

[Busted Knuckle]

I think Lee has the right idea just cut the curve out of it and replace it with a hose.

The forklift repair guy will have a solution I can almost guarantee it!
  BK 

[artvonne]

  If the line was cut and a section of hose the correct i.d. were slipped onto the line, and secured with three or 4 HD high quality hose clamps, the repair would likely out live you.

  The Bus can drive without hydraulic assist, the big issue is damage to the pump. That is easily taken care of by either removing the belt (if its belt driven) or bypassing the line back to the pump.

  You could also clamp a piece of hose against the "wound" with a HD hose clamp. As long as you don't crank the wheel aggressively or hang on the stops making the relief valve scream, its never going to reach max psi and blow a ton of fluid out. Its almost zero psi not doing anything and likely only a 100 psi or so in light applications. That kind of temporary fix may leak, but you could manage it.

[bevans6]

if it's like my power steering it's way over 1000 psi in light applications at slow speed.

Brian

[Sean]

OK, here is the latest update, and further clarifications.

Forklift guys came out, shrugged and said they could not help me.  Neither the Parker Store nor the other hydraulic hose shop in town could help -- no metric fittings.

After calling around I found one shop in town that said they could probably fix it, but I'd have to bring it to them.  They are 20 miles away.  I am going to try to effect a patch (see below) to make it that far tomorrow.

If you can't get it fixed right there, it looks like you have enough room to cut a piece of hose to slip over the pipe, then you can use a hose clamp right over the damaged area. Screw that down tight and you will be good for a few miles. It should get you to a shop.

I hope so.  What I was able to source locally was a quality stainless hose clamp with solid (non-perforated) construction and some reinforced clear vinyl 250psi water hose, 19.5mm ID.  My plan is to try to clamp right over the break, as you suggest.  I'm sure it will leak, but as long as it keeps fluid in the pump the whole time I should be OK.  The reservoir looks to be about 2 gallons; I bought five gallons of cheap ATF at Walmart this afternoon.

If that pipe is like the pressure pipe on my Neoplan, it is flared stainless steel. I had a piece shortened at a hydraulic shop and it is almost impossible to flare that size SS. The factory heats it red hot and then rolls in the flare.

I would guess it to be the same pipe or very similar.  Looks to be steel of some kind, anyway.

If you can find a compression fitting for that pipe, I would install it at the first accessible spot beyond the bend and replace that section with 4,000 or 5,000 psi hose.

Hmm.  It is my understanding that "normal" compression-type fittings will not work on straight pipe in high-pressure hydraulic applications.  Which is why there exist "cut ring" fittings which actually bite into the pipe.  I am wrong about this?

I think Lee has the right idea just cut the curve out of it and replace it with a hose.

Well, sure, but the question is how to attach the hose once the pipe is cut and all it has is an unfinished end.

The forklift repair guy will have a solution I can almost guarantee it!

Good thing you said "almost", because otherwise I'd be making you come down here to help, making good on your guarantee...

  If the line was cut and a section of hose the correct i.d. were slipped onto the line, and secured with three or 4 HD high quality hose clamps, the repair would likely out live you.

This does not sound right to me.  These systems run in excess of 2000psi -- no way a hose clamp against smooth steel can stand up to that kind of pressure.  I would estimate the size of the hole in my system to be perhaps 1/16" by 1/8", and three gallons of fluid emptied out in less than a minute once the hole burst through.

  The Bus can drive without hydraulic assist, the big issue is damage to the pump. That is easily taken care of by either removing the belt (if its belt driven) or bypassing the line back to the pump.

Sure, it can be driven without the assist -- by a gorilla twice as big as me.  I weigh 145 soaking wet, and all my weight on one side of the wheel was not enough to crank me into this parking space.  I had to back and fill four times to do what would normally take a single shot.

That said, please say more about bypassing the line.  My pump is bolted to the engine gear train, so disconnecting it is not in the cards.  The break appears to be in the return line to the reservoir from the steering box.  Do I simply couple the supply line from the pump directly to the reservoir return and then top off the system?

You could also clamp a piece of hose against the "wound" with a HD hose clamp. As long as you don't crank the wheel aggressively or hang on the stops making the relief valve scream, its never going to reach max psi and blow a ton of fluid out. Its almost zero psi not doing anything and likely only a 100 psi or so in light applications. That kind of temporary fix may leak, but you could manage it.

Well, this is my plan, as noted above.  But I am guessing it is going to leak like a sieve when maneuvering at low speed -- I'm pretty sure the pressures are in the 2000psi range, not 100 as you suggest.

It's pouring rain here now, so I am going to wait until the morning to try to patch the line.  I'll top up the reservoir and we'll see if I get any assist backing out of the space without the clamp letting go.  If I can make the turn onto the main road, it should be no problem making it to the shop.

Again, I am still open to further suggestions, especially as regards a temporary repair.  I am wondering, for example, if completely encasing the pipe in a 1/4" thick layer of JB Weld for an inch on either side of the break would hold pressure long enough to make it 20 miles.

-Sean
http://OurOdyssey.BlogSpot.com

[fe2_o3]

Does your return line really have 2000lb pressure? Usually the pressure side will, but the return side won't...Cable

[desi arnaz]

run a self tapping screw into the hole and encase it in some jb weld

[robertglines1]

I agree with screw /maybe even clamp with hose clamp for extra insurance. in case it works loose.1/4 inch screw should thread rite in. 

[Sean]

Does your return line really have 2000lb pressure? Usually the pressure side will, but the return side won't...Cable

That's a great question.  The behavior is sure one of a high-pressure line.  When I trace it past the coupler, though, it heads off to the reservoir, not the pump, which is what is making me say that it is the return line.

When the line ruptured, with a loud "bang," I lost the steering assist instantly, not gradually as the fluid bled out.  Does that suggest that maybe this is really the supply line, and I'm not understanding the layout correctly?

My system actually has three lines going to the reservoir -- one from this pipe, and two (of differing diameters) from the pump.  IIRC, one of the lines to the pump is the reservoir supply and the other is the pressure relief?

-Sean
http://OurOdyssey.BlogSpot.com