May 2009 - Accord Clutch Slave cylinder replacement

Observed symptoms:

Difficulty shifting into 1st gear from Neutral. Had to shift into 2nd to move the car a bit then shift into 1st or alternaticvely launch in 2nd gear
Observed frequency - maybe 1 out of 10 times.
I think this had progressively worsened since I bought the car in 2008


Diagnosis:
Read on the internet that the 1st gear synchro might be having a hard time engaging
Check 1: Bad Transmission fluid
Result: Noticed dealer had refilled Transmission fluid just before putting the vehicle up for sale. Opened the transmission fluid top plug (fill plug) and about 1/2 qt fluid poured out. Seems like the dealer had overfilled but I dont know how since one can never fill above the fill plug hole. Draining excess fluid helped a little but not much. So decided that transmission fluid is not an issue


Read on internet that the synchro might be having a hard time engaging due to the clutch not fully disengaging.
Check 2: Leaks in hydraulic clutch mechanism
Result: Observed clutch fluid leaking out of the clutch slave cylinder. During my first oil change I had noticed some colorless fluid on the transmission housing but did not know where it came from (now I know). The fluid was leaking inside the rubber boot of the slave cyl. Internet sources quoted a bad seal. Leaks in the hydraulic system causes loss of pressure and introduces air in the system thereby reducing the effort transmission from clutch pedal to clutch. Required action = replace with new clutch slave cylinder


Repair process:

Bought replacement slave cylinder from NAPA for $37. It was the same brand as the old one (NABCO - Made in Japan)





The rubber tip is to prevent contact wear with the clutch shift lever. The 2 rubber arms extending out are to keep the tip in place. These are supposed to break off after the cylinder is installed and the cylinder push rod is fully extended

I also got a new O-ring and a push pin with this cylinder


Prep Work:

1 small bottle Dot3 brake fluid
bleed tube and collection bottle
High temp grease


Step 1: Remove old slave cylinder

In order to uninstall the old cylinder you need to

A) Remove the 2 bolts securing the cylinder the the transmission housing

You will need to you a ratchet extension to reach these. I sprayed some WD40 on these since they were a bit rusted











B) remove the bolt securing the clutch line to the slave cylinder

This is to ensure that the clutch line is not stressed. The line seems pretty fragile and you dont want to break it. If you break it you will need to replace the entire line.







C) Detach the clutch line from the slave cylinder

The real precedure is to punch out the pin at the bottom of the line connection on the cylinder. But I as not able to punch out the pin which the cylinder was attached to the clutch line. So I detached the line at this junction. This is a brass to steel connection and so the nut is very diffuclult to remove. You will have to hold the lower nut with a wrench and then loosen the nut on the clutch line with another wrench. Do not even think of using an adjustable wrench since you will end up damaging one or both of these nuts.

This part was the 2nd hardest step of this process

Step 2: Remove the quick connect to threaded nut fitting

You need to punch out the pin to remove this fitting. This was the hardest part of the process for me. But that was because I was not using the right tools. I tried using a nail and it would no budge. I thought I will have to order this fitting from Honda. But then I tried using a small punch bit and viola it worked. This picture shows the pin and the fitting removed

You need this fitting to use with your new replacement slave cylinder.

Step 3: Installing the new slave cylinder

A) Loosen the bleed nut with a wrench and hand tighten it back

B) Install the quick connect-threaded nut fitting you removed from the old cylinder on the new one. Dont forget to use the new gasket supplied with the cylinder. Lubricate the o-ring with some brake fluid. Punch in the new pin supplied with the cylinder

C) Put some high temp grease on the rubber tip to ensure contact lubrication

D) Manually push in the push rod

E) pour in some brake fluid from the fitting opening till it starts spilling out

F) Install the cylinder on the transmission housing mounting pad. You will need to hold it in place while you insert the 2 mounting bolts. Dont forget to apply some high temp grease on the mount bolt threads

G) Reattach the clutch fluid line to the slave cylinder. Again you will need to use the 2 wrench method

Step 4: Bleeding the clutch hydraulic system

Ok now that you have the new cylinder installed, you need to bleed any trapped air in the hydraulic lines and in the new cylinder. Since we filled the cylinder with brake fluid prior to installation, there should not be too much air trapped inside the cylinder itself. You will need an assistant for this process

A) Remove the bleeder rubber cap. Insert a 1/4" clear hose over the bleed valve. Insert the other end of the tube in a collection bottle

B) Ask your assistant to step inside the vehicle and pump the clutch 3-4 times. The pedal will most likely stick to the floor. So ask your assistant to pull the pedal back up and pump it. Finally ask the assistant to hold the pedal in the depressed position

C) Loosen the Bleed valve nut with your fingers (not much room there) or using a wrench. You will see fluid and some air rising in the clear hose.

D) Tighten the bleed valve nut and ask the assistant to release the pedal.

Repeat Steps B - D 3 to 4 times till you see only fluid coming out of the bleed valve
At this point the clutch pedal should be firm indicating that the air has been bled out.

Put the bleeder rubber cap in place over the bleeder valve

Step 5: Test drive

Before starting the vehicle ensure that the gears are being engaged with the clutch depressed.

Start the vehicle and take it for a short drive around the block.

Stop and check for any fluid leaks

Thats it you are done!!!