jeff spahn

I seem to have a leak at the P/S return line on my S4 (928 347 449 07 in the PET) where it hose clamps onto the hard line. As I have no experience with this part leaking in the past I'd like to know if others had success just tightening the hose clamp or should I take it off and take it to my local hydraulic shop and have them replace the rubber hose section? Seems this would be more cost effective than buying the new $200 part.


Also, when I take this off, from what I can see in the WSM I just fill the system back up and work the bubbles out by moving the wheel back and forth?

Jadz928

Jeff,
This should give you what you need to know to fix it w/o spending much.

Dwayne's PS hose writeup at Dwayne's Garage: LINK

Make sure you replace the PS reservoir when you do this R&R. ($35 est.)

jeff spahn

If the P/S reservoir was replaced in 2008, does it need to be replaced again?

Jadz928

^^^
a couple years, probably not.

OTOH, you'll have to drain it, so why not?

StratfordShark

There shouldn't be a hose clamp there, but a metal crimp onto the hard line.

To replace the rubber line as per Dwayne's write-up and others on this forum, you dremel the metal crimp and then attach a fresh section of hydraulic line between the hard section and reservoir using a clamp. I wonder if a PO has done this and not tightened the clamp sufficiently? If it is a removeable clamp then best to replace that section of hose - the usual leak mode for return line (which isn't under much pressure) is weeping where it attaches to reservoir.

And yes you can bleed air out just by turning side to side a few times (but try no to hokd wheel against lock, which causes most stress on rack).

ammonman

Be aware that the two ends of the rubber portion of that line (928 347 449 07) are different diameters. Learned this the hard way after having the line rebuilt by a local shop and trying to get the end of the hose back onto the "cooler" hard line. The hose shop couldn't source anything with two correct sizes on either end so I had to get the line from Porsche. I suspect that the "cooler" is a larger diameter to slow the fluid down in the "cooler" section relative the rest of the system to allow more time for heat transfer.

Mike

the flyin' scotsman

Theres 2 low pressure lines on the reservoir; one feeds the pump the other is the return. If you replace both and the res plus flush the system with fresh fluid (ATF remember) you'll be good to go for years.

jeff spahn

Thanks guys

Tampa 928s

If you can't source the correct hose "two diameters", use a reducer in line!

WallyP

If there is a hose clamp, just tighten it and see what happens. If it still leaks, cut off 1/4" of the hose and re-clamp. If it still leaks, then start looking at a more drastic repair.

Cost - zero. Time - fifteen minutes. Chance of success - high.

jeff spahn

Thanks Wally. I didn't know if this was doable but I'll try it.