Turbo wastegate actuator hose deterioration

[onebob]

My Turbo wastegate actuator hose has split again - new hose 2 years ago :mad: lost boost halfway up a climb though the Toolangi forest yesterday towing a trailer. Investigated at the top of the climb and find the boost hose was completely severed at the the bottom inlet of the boost modulator - the hose had softened and swollen (a remnant of the hose and fortunately the clip was still attached to the inlet). And yes got her going again by removing and utilizing the hose that goes from the boost modulator to the induction pipe near the MAF sensor and blocking the open hole with a few wraps of lecky tape.

I'm looking for a more robust hose as a replacement that'll better handle the under bonnet environment - any suggestions anyone?

onebob

[davrac]

If your talking about replacing vacuum type hose to the boost modulator you could get some braided diesel return hose. Runs between the injectors on old school diesels. Its tuff stuff. Can get from any diesel pump specialist, don't think Repco etc will have it.

Dave

[twr7cx]

What type of hose are you using?

One of my previous vehicles was a EF Falcon XR6 with a Powerdyne supercharger, and following that I had a BA XR6 Turbo, on both I used silicone hoses under the bonnet.
When I fitted my VNT to the D2a TD5, I found some left over silicone hose (in bright blue) and used that for the wastegate actuator.
Silicone is also what the upgraded intercooler pipes are made out of, and they don't delaminate like the rubber OEM units.

Perhaps try some silicone hose?

[onebob]

thanks for the helpful replies - I am using what i thought was the best quality vacuum hose but each length swells and softens for about 40mm back from the ends... i think it doesn't like the oil vapor that is drawn into the induction pipe (pre turbo) via the PCV pipe.

onebob

[OffTrack]

I suspect it's not the oil, rather it's the temperature and pressure. The outlet temperature of the turbo can easily exceed 100°C, and the hose will be subjected to maximum boost pressure at the same time.

I went back to using genuine hoses after having similar failure occur with aftermarket hose. The LR hose to the modulator is a far more robust construction/material than the off the shelf vacuum hose I could find. I had concerns about how well the small spring lamps would retain a slippery silicon hose, but apart from that silicon would be far better than off the shelf rubber.

cheers
Paul

[twr7cx]

thanks for the helpful replies - I am using what i thought was the best quality vacuum hose but each length swells and softens for about 40mm back from the ends... i think it doesn't like the oil vapor that is drawn into the induction pipe (pre turbo) via the PCV pipe.

My understanding is that vacum hose is designed for non-boosted applications. With the boost pressure it can expand which effects the responsiveness.

[onebob]

I got 2 metres of GATES 4mm ID high pressure Fuel Hose today - I had checked out braided EFI hose and silcone gasohol hose as well but couldn't justify the extra cost versus utility when all compared .......

cheers onebob

[OffTrack]

FWIW these are the PN's for the three hoses. The Microcat descriptions are a bit obtuse for two of them.

PNH101680 - hose, wastegate control
PNH101670 - modulator to aircleaner
PNH101570 - vacuum wastegate control (shown as modulator -> wastegate in diagram)

I ended up ordering all of three, and seem to recall that the PNH101680 was the lower "problem" hose.

cheers
Paul

[onebob]

hi Paul, and yes - the bottom hose is my problem was well. Oil can contaminate that hose because PCV oil mist precipitates as oil in the compressor air stream. I will be looking next at oil catch cans i think ......

Robert

[roverv8]

Im waiting on some of this to arrive

NEW Turbo Boost Pressure NEW Silicon Silicone Turbo NA Vacuum Hose 4 MM | eBay (http://www.ebay.com.au/itm/NEW-TURBO-BOOST-Pressure-NEW-Silicon-silicone-TURBO-NA-Vacuum-Hose-4-MM-/331041203859?pt=AU_Car_Parts_Accessories&hash=item4d1397e693)