Subaru Plumb Back InstructionsUpdated 11 days ago

IMPORTANT NOTES ON YOUR SUBARU PLUMB BACK BOV

• Please thoroughly read and understand these instructions before commencing this installation.
• The thread on the cap for the vacuum source is AN#3. The standard swivel nipple can be changed to a AN#3 fitting if desired.
• The Plumb back is designed to be open at idle and does not require adjustment. 

RECOMMENDATIONS

• Turbosmart recommends that your Blow off valve (BOV) is fitted and adjusted by an appropriately qualified technician
• Turbosmart recommends that a boost gauge be permanently fitted to the vehicle
  

HOW TO INSTALL YOUR SUBARU PLUMB BACK BOV

Please check that the following items have been provided in your Subaru Plumb Back kit.

Remove the standard BOV from the intercooler by removing the two bolts. Disconnect the vacuum line to the top of the standard BOV.

Using pliers, carefully clamp onto the spring clamp on the plumb back hose and pull the BOV off the hose. Then carefully remove the clamp completely.

Remove the plumb back fitting on the back of the standard BOV and install it onto the Turbosmart BOV using the standard screws.

Push the plumb back side of the Turbosmart BOV onto the standard return pipe and secure the hose with the provided hose clamp. Unclip the hose shown in the picture from the bracket and move the line under the wiring loom that supports it.

Refit the BOV using the standard screws. Start the engine and check for leaks.

MAINTENANCE

Turbosmart recommends that the following maintenance procedure is carried out at six monthly intervals or at higher intervals if the environment is very dusty or wet. Regular maintenance will ensure that your BOV is operating at its peak performance and will extend the working life of the product.

• Remove the cap of the BOV by rotating in an anti-clockwise direction – CAUTION, the cap is under spring force, remove with care!
• Carefully remove the piston and thoroughly clean the piston and the bore of the BOV
• Inspect the surface of the piston and the bore of the BOV for scoring or excessive wear, silver coloured marks on the bore are an indication of excessive wear
• Check the Base O-ring and the Cap O-ring for any damage – replace if necessary
• Lubricate the bore and the piston with Uni-Glide™, hydraulic oil or sewing machine oil – DO NOT use grease or viscous oils
• Re-assemble the BOV in the reverse order 

TROUBLE SHOOTING

The following points should be checked if you find that your engine is dipping below normal idle, stalling or if the BOV is functioning poorly. Please note, the following checks will cure 99% of problems experienced with a BOV.

• Check the vacuum hose for splits, cracks, loose connection, kinking or any obstruction – old or fatigued hose may collapse under vacuum causing an obstruction.
• With the engine running remove the vacuum / boost hose from the nipple in the cap of the BOV, there should a loud hissing sound. The engine should idle poorly, double check by covering the end of the hose with your finger – otherwise the hose is blocked.
• Check to see if the BOV is blocked or contaminated with dirt or debris.
• Ensure that the vacuum / boost source is not shared and that the vacuum source is directly from the inlet manifold.
• Check the seal between the intercooler flange and the BOV.  Make sure the supplied gasket is installed and the BOV Flange is secured on the intercooler flange with the two factory bolts.
• Ensure the spring clamps are secured on silicon hoses and fittings.
• Failing the above, submit a technical request to [email protected] with information of your engine configuration and photos of installation and one our expert technicians will respond as soon as possible. 

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