Recommended maintenance: Replace vacuum hoses at 100K miles
 

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I decided to pull of the intake manifold to make it easier to replace the PCV valve and knock sensors, and so I decided to do all vacuum hoses too. Glad I decided to go that way. Virtually every hose had hardened to the point of being almost non-flexible. I suspect that many of the hoses would have started leaking vacuum within the next 20k-30k miles.
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Gee, I will have to go out and check mine. :)

How many can be replaced with standard hose and how many need to be the OEM pre-bent hoses?

Doug

I think that all of the vacuum hoses could be replaced with straight hose, but it would be necessary to get high quality hose that's got the proper metric ID. I tried some 1/8" vacuum line I picked up at Schuck's, and the ID was too big for a good seal. I'd probably go with viton hose which has a greater heat range than standard nitrile rubber and can withstand gasoline fumes (unlike silicone hose).

I don't have to go under my hood to know most of my hoes are hard as rocks. :(

I replaced all mine a while ago with just bulk straight hose. You don't need the pre bent hose as long as you can remember which hose hooks to what terminal.

Almost all of mine were dry and brittle. I'm sure I was losing vacuum with the condition they were in.

Mychailo,
Gee, what a surprise that the lines were rock hard :rolleyes: :D
Can you post your source for viton hose when you find it? Thanks.
-Bill

I took a look at that vacuum tubing again, and its actually 4 mm vacuum tubing. Too big. 1/8" should work fine.

My favorite raw material supplier, McMaster-Carr, has viton hose. Do a search on "viton tubing". You'll find it in a variety of diameters, both SAE and metric. Get the Shore A 60 durometer stuff. Here is a list of all the vacuum/air hoses under/around the intake manifold:

http://www.subaru-svx.net/photos/fil...czko/29136.pdf

Mychailo,
Well, the viton is here and ready to go. Looking at the valves that came with my "spare" intake, two of them have snapped off hose connectors :mad: Can you confirm that I've got the following part numbers right:

http://www.subaru-svx.net/photos/fil...Ride/30472.jpg

Thanks in advance for your help on this!

-Bill

Hi Bill,

Those part numbers look correct to me except that 14474AA271 looks like it should be 14471AA391 (updated). 16102AA020 is the solenoid that I broke and had to replace. If you're mail ordering, Jason at Auburn Subaru (WA) has the best prices. 866 528-5282.

BTW, if anyone is interested in tackling this, I wrote a how-to on it. Its in the how-to locker:

http://www.subaru-svx.net/photos/files/How-To/30340.pdf

Re: recommended maintenance: replace vacuum hoses at 100K miles
 

Old thread revival...

I ordered some Viton hosing from McMaster but I want to make sure that the hose I received is indeed the 60 "firm" and not 70 "soft" variety.

What had happened was I placed the order and accidentally ordered the soft hose. I immediately messaged customer service and asked to switch the type, they responded quickly that they did but I received my hose and I am not sure what I got. The packing slip still says soft so that's why I am concerned.

Re: recommended maintenance: replace vacuum hoses at 100K miles
 

For any future searches, the firm hose feels more like a pencil eraser and the soft hose is more like a rubber band.

I also found out that the majority of the vacuum hoses I ordered from Subaru were on national backorder...

Re: recommended maintenance: replace vacuum hoses at 100K miles
 

Big thanks to mbtoloczko for writing this up years ago. I tackled this project over the weekend. My 92 with 160k desperately needed replacing of all vacuum lines, hoses, pcv and knock sensors (both were cracked).

The longest part was actually getting the parts. Some hoses were on back order and took longer than expected to ship. However the following hoses are no longer available:

807607992 (throttle body water hose #1); 807412162 (aux air hose #2; 807503900 (small vacuum hose upper rear throttle body #1); 807504442 (vacuum hose into small black box) and 807520162 (idle air control hose).

Each had hardened to the point they could be broken in half. As careful as I was i managed to break the vacuum box and both solenoids under the intake manifold. The hoses essentially bonded to the plastic and the slightest torque applied simply snapped the plastic valve. Fortunately I had a spare intake manifold and was able to safely remove the hoses from those solenoids. I used a dremel and carefully cut the rubber to help speed up the process.

If the SVX is your daily driving or if you need it the next day, definitely consider purchasing the solenoids beforehand. Due to the limited availability and delays in shipping, if you break a part you may be svxless for at least a week.

One note is that I had to remove the alternator and loosen the a/c compressor to allow enough clearance to remove the driver's side intake manifold with the fuel lines.

Btw, what's the secret to uploading pics to this site? Each time I try, my upload "fails".

Thanks again for a great write up and taking the time to include all the part numbers, descriptions and alternative part sourcing.