Archived Hissing noise

[jClifford]

I have an 08 3500 Dually. It has developed a low hissing noise the seems to be coming up through the steering column. I hear it whatever gear the truck is in, whether the truck is moving or not. It stops when I apply the brakes and is intermittent as I turn the wheel.

 

[Bob4x4]

The liner in the hydroboost line has slipped.t0 verify it you can disconnect the line at the hydroboost pull the liner out and reassemble-your noise will be gone

 

[RustyJC]

I just had this happen last weekend on my 2011 towing the 5th wheel back home from a trip. The hydroboost line between the pump and steering rack (it's a 2WD) failed internally (the service tech's words), although it wasn't dumping fluid on the ground, resulting in a loud hiss that stopped whenever I turned the steering wheel or stepped on the brake pedal. The dealer replaced the hose, topped up the system, bruised my credit card and all's well again.

Rusty

 

[Wayne M.]

I believe the "internal failure" story. The inner liner of the hose breaks down/ collapses and wired things go on. It happens to brake hoses too.

 

[Bob4x4]

I believe the "internal failure" story. The inner liner of the hose breaks down/ collapses and wired things go on. It happens to brake hoses too.

What happens is the liner does not break down or collapse it shifts and travels into the hydroboost unit,the way the fluid hits the edge produces the noise

 

[jClifford]

Thanks to all. It was an easy fix. The inner tube slipped into the hydroboost unit by about 3 inches.

I saw on a video that you can simply slide the inner tube out completely. That took care of the hissing noise but I'm now wondering how long it will take the brake fluid to eat through the hose and state leaking. I guess a complete line change is next on the agenda.

 

[petersonj]

That took care of the hissing noise but I'm now wondering how long it will take the brake fluid to eat through the hose and state leaking.

Power steering fluid runs through this hose, not brake fluid.

- John

 

[Wayne M.]

BOB nailed it! That is a special hose with that liner in it.

 

[seafish]

So does the liner need to be replaced or can the hose be run without it??

Also curious why the liner slips…I guess its not full length??

 

[Bob4x4]

That's right Sea the liner is not full length.I have heard a lot of different theories why the liner is there I am not sure any of them are correct.I did have a customer who did not want to buy the hose and left with no liner,he has not reported any failure with the line yet.

 

[RustyJC]

I suspect, since the hose assembly is part steel and part rubber, the liner was intended to be positioned in the rubber section. Having said that, if the fit is loose enough that the liner can move, then I question its value since the hydroboost fluid would be able to get between the liner and outer rubber hose, exposing the outer hose to full system pressure as well as the fluid itself with the associated potential for chemical degradation. I know one thing for sure after having mine replaced....FCA is PROUD of the replacement hoses!!

Rusty

 

[seafish]

Bob and Rusty, thanks for the update,…sounds like running without the liner is OK then.

 

[jClifford]

Thanks. I knew that. Don't know what I was thinking about.

 

[cerberusiam]

I suspect the real answer comes down to $$. Rather than spend the dollars for the correct hose a cheap plastic liner was used to stop erosion and collapsing of the rubber line leading to contamination and catastrophic failure. Financially, selling new hoses makes much more sense that using one that would almost never be replaced.

 

[seafish]

So i could have one made up at my hydraulic shop from standard hyd hose if or when the oem booster hose fails??

 

[cerberusiam]

So i could have one made up at my hydraulic shop from standard hyd hose if or when the oem booster hose fails??

As long as those fittings are not some odd ball thing that is impossible to get you can likely get a better hose than OE made up at most hose shops. It will depend on what you have in that area, int he oil fields pretty much anything is available in hose. The other issue is whether they can make any custom bends on the ends outside the standard. 12 inches of metal bent in 3 dimensions they don't like or won't tackle a lot of times.