7.3L Injector Cup Replacement

3. August, 2012

Ford Mod Installations

IMPORTANT: Before starting installation, please be sure that all items which were supplied with the kit are accounted for.

Recommended Tools:
‐SAE and Metric Sockets and Wrenches
‐90o Die Grinder with cutoff wheel.
‐RPD HPOP Hose Quick Disconnect Tool

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Required Parts:

F4TZ9F538A Injector Cups

Cup Retaining Compound (Ford Spec WSK‐MZG351‐A6)



1) Disconnect the negative cables from both batteries.

2) Drain the coolant from the radiator using the petcock. Fluid level needs to be lower than the heads.

3) Remove the coolant plugs from the each side of the block. They are ¼” square drive plugs. Drivers side is aft of the oil filter housing. Passenger side is located behind the starter motor.

4) Remove the fuel injectors from the heads.

5) Insert the RDP Injector Cup Removal tool into the injector bore. Make sure the arrow is pointing towards the valve springs (Fig 1).

6) Install the bolts (2) into the injector hold down holes. Tighten down bolts to 10 ft‐lbs.

7) Turn the outer bolt (smaller size) clockwise while pushing down to engage the tool into the injector cup. 1‐2 full turns is all that is needed. Caution: If you thread it in to far it can make the cup harder to remove. (Fig 2)

8) Once the tool is engaged into the cup. Turn the nut clockwise with a socket to pull the cup from the bore (Fig 3). When the cup releases, remove the tool from the head.

9) Remove sealant residue from the injector cup bore in the head using Injector Sleeve Brush set or equivalent. Make sure the bore is oil free to ensure the retaining compound adheres.

10) Remove the injector cup off of the tool using locking pliers and a wrench to hold the tool. (Fig 4)

11) With the cup removed from the tool, you can see the engagement of the tool to the cup. (Fig 5)

12) Place the new injector cup onto the installation tooling. The cup is retained on the tool by an o‐ring. Make sure the cup support mandrel is threaded all the way up to the holding plate. Clean the outer surface of the cup to remove oil residue. Apply the cup retaining compound to the vertical flanges of the cup as shown. (Fig 6)

13) Center the tool into the bore and install the cup being careful not to get the compound on the bore until it is fully installed. Install the bolts through the holding plate and tighten to 10 ft‐ lbs. (Fig 7)

14) Seat the cup into the bore by tightening the mandrel bolt . You do not need to over tighten the bolt (roughly 20 ft‐lbs is all that is needed). Once the cup seats into the bore, you no longer need to tighten the bolt. (Fig 8)

15) Remove the tooling and wipe any excess compound squeeze out from the bore.

16) Repeat for all other cylinders.

17) Caution: Make sure you allow the compound on the cups to cure for a minimum of 12 hours before starting the engine. This will ensure adequate bond time which will prevent leaks.

18) Reinstall the fuel injectors.

19) Re‐install the coolant plugs on the block and refill the coolant system.

20) Reconnect the negative cables to the batteries.

21) After performing this work, you may experience slow starts and rough running for up to 50 miles due to air in the system.


Special thanks to FTE members Lloydable for the pictures and Woodnthings for the instructions!

Disclaimer of Warranties and Liabilities
Riffraff Diesel disclaims any responsibility/liability for improper, incorrect, or inexperienced installation of products by the consumer or paid installer resulting in damage or loss. Buyer affirms by purchase of this product that it is fit for intended use and accepts all liability.

Buyer affirms products purchased are engineered to increase automotive performance and are used at buyers own risk and accepts full responsibility.