Replacing an F-hose
06-24-2002, 11:27 AM
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Replacing an F-hose
Well, as noted in a few posts below, I did find the source of the boost leak - the F-hose was torn. I replaced it this afternoon, and all is well again. (It's really good to have the boost back, I feel so much better...)
Anyway, with some of the recent questions on it, I thought I'd give some abbreviated instructions on checking it, and replacing it...
If you are experiencing a loss of boost, particularly at higher RPM, it's worth checking the f-hose. I could actually hear a "wooshing" noise under boost. This may have been the turbo wastegate... To check the f-hose, first you have to find it. It is located just under and behind the passenger-side Diverter Valve. See picture below.
<img src="http://pictureposter.audiworld.com/3729/fhose-after.jpg">
You can check it without removing the DV - just run your hand under and around the hose. You may be able to feel the split. If it's oily and dirty on the hose and just below it, it's probably bad.
<b>To Replace</b>
This take about an hour. You'll need the replacement F-hose, 3 hose clamps, a long and short flat-blade screwdriver, long-nose pliers, and a light.
1. Get the replacement part. Part number is:078-133-784-AJ. Samco also makes an F-hose in silicone - a lot less likely to split again...
2. Remove the plastic engine cover over the TBB. (The "big" one).
3. Remove the passenger side Diverter valve. You may be able to skip this step, but it makes it a lot easier. If you have never removed your stock DV's, this could take a little time, and requires 3 more hose clamps. If you still have stock DV's, this might be a good time to swap in the "upgraded" Bosch DV's... Hint: cover the open hoses with a piece of duct tape to prevent bits of hose clamp (from next step) from falling into the airflow...
4. You can now see the F-hose! You'll have to remove the factor "crimp-on" hose clamps. I did this by inserting a small screwdriver blade into the crimp, and prying it open a bit. I then worked my way counter-clockwise around the clamp until I popped one end off. I then used the long-nose pliers to pull the rest of the clamp off. Repeat with the other 2 clamps. They are hard to get to, but ya gotta do it...
5. Congrats - the hard part is done. Remove the old f-hose. You may see an evil split, as pictured below:
<img src="http://pictureposter.audiworld.com/3729/tornfhose.jpg">
6. Put a hose clamp on the "middle" finger of the f-hose, and attach that first. You can pull the check valve that it attached to up a little to make that easier. Do the "top" of the hose next, attaching it to the throttle body. Then, attach the base of the "f"...
7. Be sure all clamps are tight. Re-install the Diverter Valve and the engine cover. Drive happy...
Anyway, with some of the recent questions on it, I thought I'd give some abbreviated instructions on checking it, and replacing it...
If you are experiencing a loss of boost, particularly at higher RPM, it's worth checking the f-hose. I could actually hear a "wooshing" noise under boost. This may have been the turbo wastegate... To check the f-hose, first you have to find it. It is located just under and behind the passenger-side Diverter Valve. See picture below.
<img src="http://pictureposter.audiworld.com/3729/fhose-after.jpg">
You can check it without removing the DV - just run your hand under and around the hose. You may be able to feel the split. If it's oily and dirty on the hose and just below it, it's probably bad.
<b>To Replace</b>
This take about an hour. You'll need the replacement F-hose, 3 hose clamps, a long and short flat-blade screwdriver, long-nose pliers, and a light.
1. Get the replacement part. Part number is:078-133-784-AJ. Samco also makes an F-hose in silicone - a lot less likely to split again...
2. Remove the plastic engine cover over the TBB. (The "big" one).
3. Remove the passenger side Diverter valve. You may be able to skip this step, but it makes it a lot easier. If you have never removed your stock DV's, this could take a little time, and requires 3 more hose clamps. If you still have stock DV's, this might be a good time to swap in the "upgraded" Bosch DV's... Hint: cover the open hoses with a piece of duct tape to prevent bits of hose clamp (from next step) from falling into the airflow...
4. You can now see the F-hose! You'll have to remove the factor "crimp-on" hose clamps. I did this by inserting a small screwdriver blade into the crimp, and prying it open a bit. I then worked my way counter-clockwise around the clamp until I popped one end off. I then used the long-nose pliers to pull the rest of the clamp off. Repeat with the other 2 clamps. They are hard to get to, but ya gotta do it...
5. Congrats - the hard part is done. Remove the old f-hose. You may see an evil split, as pictured below:
<img src="http://pictureposter.audiworld.com/3729/tornfhose.jpg">
6. Put a hose clamp on the "middle" finger of the f-hose, and attach that first. You can pull the check valve that it attached to up a little to make that easier. Do the "top" of the hose next, attaching it to the throttle body. Then, attach the base of the "f"...
7. Be sure all clamps are tight. Re-install the Diverter Valve and the engine cover. Drive happy...
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