How To Install a Clutch Line in Your 240SX LS1 Swap

How To Install a Clutch Line in Your 240SX LS1 Swap


When it comes to the GEN III GM LS series of engine, the most popular type of transmission found in swaps is the T56 Tremec. This transmission is one of our personal favorites, with solid gate work and confidence inspiring shifting all in a neat package that’s willing and able to take abuse. The fact that may people opt for the T56 as a swap transmission candidate only speaks to the LS1’s long list of positives with relatively few cons.


One such con for 240SX LS1 Swap owners is the location of the slave cylinder / throwout bearing, which resides inside the transmission bell housing. As the hydraulic system has no real way of bleeding from the outside of the car, you should most definitely purchase a hydraulic remote bleeder.

The slave cylinder we are looking at today is Centric part number 138.66006 and this is mounted inside your transmission bell housing.


The only other way to bleed this clutch in a 240SX would be to drill a hole in your floorboard, on the driver side of the transmission tunnel and use a long extension. In other words, it’s not recommended and you definitely need a remote bleeder for convenience and practicality.

This fitting allows you to attach a -3 AN line to your OEM GM LS style T-56 throwout bearing.


To begin, remove your transmission and locate your adapter fitting, this can be a -3 or -4 depending on the style of master cylinder you are using. We prefer the -3 AN which helps keep pressure up and reduce the amount of deflection that will occur with free floating clutch lines.

We’ve seen -4 AN setups feel far too mushy with a 7/8 master cylinder bore, this may change if you opt for a partial hardline that is somehow secured to the frame or motorset.

Start by gently knocking out the roll pin located in the slave cylinder housing, as shown below.

Use a hammer and gently tap this pin out.

Slide out the roll pin out and set it safely to the side as you will be reusing it shortly. Pull off the original fitting, and make sure that the rubber gasket is also removed at the same time.

Remove and discard
Remove and discard

Now install your new AN adapter fitting, and make sure that your rubber oring does not become damaged or kinked during installation. While pressing in the new fitting, gently re-insert the roll pin and tap in with a hammer.

Make sure the rubber o-ring is removed before installing your new unit

If you are bleeding or pre-bleeding the clutch with a prefilled clutch line, make sure you do not interrupt or otherwise introduce air into the line.

Gently reinsert and tap roll pin into place

Now with your clutch line attached you are ready to route the clutch hose up near your master cylinder. Hopefully you will have installed your master cylinder already with the proper bracing, and you should now be ready to bleed your clutch hydraulics and start your car.

We recommend the 7/8 Wilwood master cylinder
We recommend the 7/8 Wilwood master cylinder

For more information on How To Swap a LS1 into a 240SX, or How To Wire a LS1 into a 240SX, check our articles here. If you need information on how to install your wilwood master cylinder, refer to the links below.