Power steering return line keeps blowing at cooler 95' 7.4 Bravo1

[tango13]

Hi all,
Long story short is that I've blown PS return line right at the cooler for the 3rd time now. 1995 7.4 Bravo 1. I kept trimming the hose where it would burst/crack, and kept reinstalling until i finally ran out of line length and ended up replacing the entire part with a new quicksilver line & fitting. Line blew twice during idle speeds and once at WOT. Blew twice on my own (1st and 3rd) and once on my mechanic while it was idling on muffs, who ended up pulling the cooler to inspect and found no issues on that end.

Just curious as to whether these older rubber lines are known to break down over time? I inspected the nipple on the cooler and the hose clamp and didn't see any visible sharp edges. I'm hoping the new hose holds up, as its a major PITA to clean up the mess of ATF in the bilge when it leaks and fix the hose end. Not to mention a new part was $$$ for what it was (now I understand why my mechanic wanted to avoid changing the whole unit).

 

[Scott06]

Hi all,
Long story short is that I've blown PS return line right at the cooler for the 3rd time now. 1995 7.4 Bravo 1. I kept trimming the hose where it would burst/crack, and kept reinstalling until i finally ran out of line length and ended up replacing the entire part with a new quicksilver line & fitting. Line blew twice during idle speeds and once at WOT. Blew twice on my own (1st and 3rd) and once on my mechanic while it was idling on muffs, who ended up pulling the cooler to inspect and found no issues on that end.

Just curious as to whether these older rubber lines are known to break down over time? I inspected the nipple on the cooler and the hose clamp and didn't see any visible sharp edges. I'm hoping the new hose holds up, as its a major PITA to clean up the mess of ATF in the bilge when it leaks and fix the hose end. Not to mention a new part was $$$ for what it was (now I understand why my mechanic wanted to avoid changing the whole unit).

So it hasn't blown since you replaced it completely? If it hasn't yes I would blame it degradation of the hose. In hydraulics except in a pinch we never put a new end on an old hose for that reason. Inside of hose may have broken down restricting flow to where pressure builds up

 

[tango13]

So it hasn't blown since you replaced it completely? If it hasn't yes I would blame it degradation of the hose. In hydraulics except in a pinch we never put a new end on an old hose for that reason. Inside of hose may have broken down restricting flow to where pressure builds up

Just replaced last night in the garage, blew for the 3rd time last week while on vacation. Band aid fixed it by trimming down but after three times it was obvious that something was wrong. Just hoping that the new line holds steady

 

[Bondo]

Ayuh,.... Did you blow through the cooler to make sure it's clear,..??

That line should be free flowing to the reservoir,...

 

[tango13]

Ayuh,.... Did you blow through the cooler to make sure it's clear,..??

That line should be free flowing to the reservoir,...

Confirmed flow, Cooler was inspected and I had backflow from the reservoir

 

[Scott Danforth]

You are using Power Steering return hose, correct?

It's rated about 100 psi with a 400 psi burst

Regular hose won't cut it.

 

[alldodge]

Ayuh,.... Did you blow through the cooler to make sure it's clear,..??

That line should be free flowing to the reservoir,...

Agree, that hose should never see much above 10 psi if that.

You sure that's the return line and not on the pressure side?

If should come from the ram, thru cooler to reservoir tank, "open flow" no restriction

 

[tango13]

You are using Power Steering return hose, correct?

It's rated about 100 psi with a 400 psi burst

Regular hose won't cut it.

Yes, its a Quicksilver return line. #32-806221.

 

[tango13]

Agree, that hose should never see much above 10 psi if that.

You sure that's the return line and not on the pressure side?

If should come from the ram, thru cooler to reservoir tank, "open flow" no restriction

Positive its a return line, threaded fitting on the steering ram side, and a rubber hose clamped on the cooler side. Quicksilver part# #32-806221. Agreed it should be very low pressure, open flow. My system works fine, and I've witnessed back flow from the pump reservoir back to the cooler and out the inlet from the ram so I know there is unrestricted flow. I bled the system after the last line failure and it was successful.

The rubber hose end isn't necessarily dramatically "blowing off", I guess i should have called it "quick deterioration". It will spring a leak through those right around where it connects to the cooler, and then leak out all the fluid. I've been finding cracks in the hose where its leaking, and that's why I'm wondering if these hoses become compromised with age or if there is something else that's causing pre-mature failure> Time will tell if the new line solves it but it would be nice to know if it is/was a common issue

 

[Scott Danforth]

It is not a common issue

 

[04fxdwgi25]

Interesting. Stated it was line from cooler to PS pump.

Never seen a return line to the PS pump "blow". Rub thru: yes, Fall apart from age: Yes. But never blow, since there is zip on it for pressure.

It would see pressure if there was a serious restriction at the the return fitting on the pump, maybe from a chunk of the hose liner breaking off and plugging the return port.

I would lean towards just plain old age and it's due for replacement.